A peptide pheromone, sodefrin, has been considered to be a major female attractant released from the abdominal gland of male newts. By means of gas chromatography-mass spectrometry, we demonstrated that a considerable amount of steroidal substances such as pregnenolone, progesterone, androstenedione and estradiol were contained in the abdominal gland of the male newt. Moreover, we confirmed that synthesis and release of steroidal substances such as pregnenolone and androstenedione occur in the abdominal gland. Moreover, we found both of these steroids have a considerable female-attracting activity. Combination of both steroids and sodefrin exerted more potent female attracting activity than the mixture of the two steroids or sodefrin alone. The results strongly suggest that both the peptide pheromone and the steroids act together to attract sexually developed females during courtship. [J Physiol Sci. 2008;58 Suppl:S141]

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During amphibian fertilization, sperm bind to vitelline envelope (VE) that surrounds an egg, and undergo acrosome-reaction that enables sperm to penetrate the VE. Sperm-egg fusion activates an egg and resumes the cell cycle. Despite considerable lines of evidence, molecular mechanisms of fertilization remain to be elucidated because of the conflicting results. To understand molecular mechanism of sperm-egg ineraction, we have characterized a 26 kDa Ca²⁺-binding protein, Xenopus dicalcin, in Xenopus eggs. Xenopus dicalcin is localized prominently in the VE of Xenopus eggs, and dicalcin binds to protein cores of two constituent glycoproteins in a Ca²⁺-dependent manner. Since these two VE glycoproteins are considered to function as sperm-receptors, we tested the effect of dicalcin on sperm-VE binding and fertilization in vitro. Preincubation of eggs with recombinant dicalcin reduced the number of sperm that bound to VE as well as the efficiency of fertilization. In contrast, inhibition of intrinsic dicalcin by preincubation of anti-dicalcin antibody increased sperm-binding to VE and the efficiency of fertilization. These results indicated that dicalcin inhibits sperm-egg interaction and subsequent fertilization. [J Physiol Sci. 2008;58 Suppl:S141]

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We previously demonstrated that irritating dietary substances such as papain and capsaicin induced cystatin S in submandibular saliva of rats. In order to expand knowledge about induction of salivary proteins by a dietary constituent, we investigated the effects of dietary quinine, the bitter principle of tonic water, on the submandibular gland and its saliva in rats. Dietary quinine (973–9730 ppm) increased the weight of the submandibular gland and induced at least six cystatins (apparent molecular weight: 14–45 kDa) and induced/upregulated at least five quinine-binding proteins (apparent molecular weight: 14–105 kDa) in submandibular saliva by three days after the beginning of feeding. In contrast, the group treated repeatedly with 97.3 ppm–saturated quinine solutions through an oral cannula showed a similar electrophoretic pattern of saliva as for the intact control group (no cystatin and very low quinine-binding protein). These results suggest that the combination of masticatory and gustatory stimulation is required for induction of cystatins and upregulation of quinine-binding proteins in saliva by dietary quinine. [J Physiol Sci. 2008;58 Suppl:S141]

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By measuring the gastrointestinal motility, this study is aimed at obtaining a mathematical model of electrogastrography (EGG) and speculating factors to describe the diseases resulting from constipation and erosive gastritis. Initially, we applied the Double-Wayland algorithm to the EGG in order to measure the degree of determinism. As a result, we could not decide whether a chaotic process is appropriate for the mathematical model of the EGG. On the other hand, the waveform of the electric potential in the Cajal cells is similar to the graphs of numerical solutions to the van der Pol equation (VPE). Hence, we added the VPE to a periodic function and random white noises named after the intestinal motility and other biosignals. We rewrote the stochastic differential equations (SDEs) into difference equations, and the numerical solutions to the SDEs were obtained by Runge-Kutta-Gill formula as the numerical calculus, where we set the time step and initial values to be 0.05 and (0, 0.5), respectively. Pseudo-random numbers were substituted in the white noise terms. In this study, the pseudo random numbers were generated by the Mersenne Twister method. These numerical calculations were divided into 12000 time steps. The numerical solutions and EGG were extracted after every 20 steps. The EGG and numerical solutions were compared and evaluated by the Lyapnov exponent and translation error. The EGG was well described by the stochastic resonance in the SDE. [J Physiol Sci. 2008;58 Suppl:S141]

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C-terminus of AMPA receptor GluR1 contains phosphorylation sites, which may be involved in forms of synaptic plasticity such as LTP or depotentiation by regulating synaptic incorpolation of AMPA receptor or its internalization. However, little is uncovered on the roles of GluR1 C-terminus in synaptic plasticity in vivo study. To clarify the roles of GluR1 C-terminus in synaptic plasticity, we performed delivery of specific antibodies to GluR1 C-termunus containing S831 and S845 into hippocampal CA1 cell by injection of HVJ-envelope vector complex containing antibodies. During 5-6 days after delivery of antibodies into CA1 cells, behavioral tests using a watermaze task, prepulse inhibition (PPI) test of acoustic response, and open field (OP) test are conducted in antibody-treated, vehicle-treated and control rats. In watermaze task, antibody-treated rats displayed complete inability of spatial learning by loss of searching behavior or loss of motivation for escape, while vehicle-treated rats showed deficit of spatial memory and normal searching behavior. In OP and PPI test, antibody-treated rats show normal PPI and adaptive behavior. We discuss that the behavioral abnormality probably by loss of motivation seen in antibody-treated rats may be interpreted by antibody-induced disruption of interaction between GluR1 phosphorylation site like S831 and protein phosphatase in hippocampal CA1. [J Physiol Sci. 2008;58 Suppl:S142]

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We investigated how hippocampal place cells encode a continuously moving object in the environment. Neuronal place cell activities were recorded from freely moving rats when a toy car was introduced in an open field. First, in a freely moving (FM) task without the car, the rats freely navigated inside the open field to acquire intracranial self-stimulation (ICSS) reward by each travel of 150 cm. Second, they were then divided into 2 groups and tested by 2 different tasks. In a car-dependent navigation (CDN) task, a toy car was placed inside the open field. The rat could receive ICSS if it chased and approached the car within 20 cm distance from the car. In a car-independent navigation (CIN) task, the rat could acquire ICSS rewards if it traveled 150 cm path regardless of the car. Place fields remapped more frequently in the CDN than CIN tasks. In both the CDN and CIN tasks, the place neuronal activity was significantly modulated by movement parameters of the rat, car and distance between the car and rat. However, tuning of the place cells to movement variables of the car as well as the rat was more selective in the CDN than CIN tasks, while information regarding movement variables represented by the place cells was larger in the CDN than CIN tasks. These results indicated that place cell activity within the place fields represents not only own location but also movement variables of other moving object in the environment. [J Physiol Sci. 2008;58 Suppl:S142]

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Although learning induces long-term potentiation in hippocampal area CA1, the molecular and cellular mechanisms underlying learning-dependent plasticity of CA1 pyramidal neurons are still unknown. By combining in vivo gene delivery with in vitro patch-clamp recordings, we found that hippocampal-dependent inhibitory avoidance (IA) learning drives recombinant GluR1, an AMPA receptor subunit, into synapses formed between CA3 and CA1 pyramidal neurons. For the in vivo gene delivery, we used recombinant Herpes virus injected into the dorsal hippocampus of male rats at 4 weeks of age. The brain was sliced 30 min after the IA training, and infected neurons were identified by the GFP tag on GluR1. Moreover, IA learning significantly increased AMPA/NMDA ratio suggesting synaptic delivery of endogenous AMPA receptors. For the behavioral study, recombinant Herpes virus were bilaterally injected into the dorsal hippocampus to express the GluR1 cytoplasmic tail in CA1 pyramidal neurons, a construct that inhibits synaptic delivery of endogenous AMPA receptors during long-term potentiation in vitro and experience in vivo. The expression of GluR1 cytoplasmic tail successfully impaired the IA learning performance without changing the latency to enter the novel dark box or the amount of 24-hour spontaneous locomotor activity. These results show that synaptic delivery of AMPA receptors into Shaffer collateral synapses plays an essential role in hippocampal-dependent learning function in behaving rats. [J Physiol Sci. 2008;58 Suppl:S142]

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Purpose of this study was to investigate whether protective effect of exercise on stress-induced impairment of spatial memory may be dependent on insulin-like growth factor 1(IGF-1). Male C57BL/6 mice were divided into four groups; control, immobilized, exercised and JB1-administrated mice. Control mice were fed in normal cage without immobilization and exercise. Immobilized, exercised and JB1-administrated mice were individually fed in small cage and exposed to 8 h of immobilization 6 days per week. Exercised and JB1-administrated mice were performed 1 h of treadmill running 6 days per week. All of mice were implanted osmotic pump that contained JB1, antagonist for IGF-1 receptor, in JB1-administrated mice and saline in control, immobilized and exercised mice. Four weeks later, spatial learning was measured by Morris water maze test. After water maze test, brains of mice were excised under anesthesia and used for immuohistochemical analysis with antibody of Ki67, which is neurogenesis marker. Chronic immobilization impaired spatial memory and suppressed Ki67-positive cells in dentate gyrus of hippocampus. Exercise prevented impairment of spatial memory and suppression of Ki67-positive cells, while JB1 canceled protective effect of exercise on spatial memory and numbers of Ki67-positive cells. These findings suggested that protective effects of exercise on stress-induced impairment of spatial memory were dependent on IGF-1. [J Physiol Sci. 2008;58 Suppl:S142]

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In urethane-chloralose anesthetized pigs, we examined theta activities in the temporal hippocampus by odor stimulation with the commonly used odor, beta-phenyl ethyl alcohol (PEA; rose-like odor). By stimulation with lower concentration of PEA (10⁻⁴w/w), power of type-1 theta (6-12 Hz) remained almost unchanged, but that of type-2 theta (4-6 Hz) was significantly increased. By stimulation with higher concentration (10⁻³w/w) of PEA, power of the type-1 and type-2 theta both gradually increased. The present study indicates the type-2 theta activity to the hippocampus of the pigs can separately be activated from the type-1 theta by odor stimulation with the low concentration of PEA. The type-1 theta may be activated with the type-1 in the temporal hippocampus of the pigs by stronger odor stimulation with PEA. Neural subsystems producing two theta rhythms to the hippocampus may be present which underlie olfactory cognition in the brain of the pigs. [J Physiol Sci. 2008;58 Suppl:S143]

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The prefrontal cortex (PFC) and hippocampus (Hip) are important brain regions for learning and memory. The anatomical connection between both regions is well known. The aim of this study was to investigate relationship between these regions based on the correlation of neuronal activities. Under urethane anesthesia, the recording electrodes were implanted into PFC and Hip according to anatomical data reported previously. After that, multiple unit activities (MUAs) of both regions were recorded simultaneously. Analysis of cross-correlograms (CCs) between MUAs revealed significant peaks. They had lags mainly from Hip to PFC. The peaks of those CCs (MUA-based CCs) could reflect relationship between individual spikes and/or population of spikes. To evaluate contribution of these factors, we calculated CCs based on spike density function (SDF), which mainly reflects function of population of spikes. There were no significant differences in lags between MUA-based CCs and SDF-based CCs. These results suggest that relationships between population of spikes not individual spikes contribute to our observed peaks of CCs. Significant information may be conveyed by population of spikes at least in Hip-PFC communication. Such a communication based on population of spikes between Hip and PFC could provide some gates for information flow between these regions. [J Physiol Sci. 2008;58 Suppl:S143]

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In rodents, the medial prefrontal cortex (PFC) is involved in the suppression of temporally inappropriate responses. This raises a possibility that the PFC plays an important role in a delayed reinforcement operant task. If so, the PFC may exhibit neuronal activities during the delay period related to withholding the impulse to respond or timing the response correctly. To address this issue, we investigated the effects of transient PFC inactivation on a delayed reinforcement lever-press task. The effects of hippocampal inactivation were also tested for comparison. In a separate experiment, we recorded the multiple unit activities (MUAs) of the PFC during the task. The inactivation experiment showed the involvement of the prefrontal cortex in this task: prefrontal cortex inactivation but not hippocampal inactivation significantly impaired the performance of the delayed reinforcement task. The present MUA analysis revealed a significant decrease in the PFC neuronal activities during the delay period. These results indicate the involvement of the rat PFC at least in a certain type of delayed reinforcement operant behavior, in which a sustained decrease in the PFC neuronal activities during the delay period may play a role in a neuronal function performed by the PFC in the inhibitory control of behavior. [J Physiol Sci. 2008;58 Suppl:S143]

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To understand the evolution of human behavior and brain, it is fundamental to determine how brain development of humans differs from that of chimpanzees (Pan troglodytes). The area of particular interest for human evolution is the prefrontal area, which mediates high-order behaviors such as, working memory, attention, planning, decision making, or social behaviors. We studied the development of the gray matter (GM) and white matter (WM) in the frontal area of 1 male and 3 female chimpanzees, at the ages of 2 months to 7 years old. MRI images were acquired using T1-weighted, gradient echo imaging with a 0.2T MR imager. We examined GM and WM volumes in the prefrontal area, the frontal area, and the whole brain using FSL software. The prefrontal and the frontal areas were defined as all portions anterior to the corpus callosum and the anterior commissure respectively, in a plane perpendicular to the line connecting the anterior and posterior commissures. The results revealed that (1) growth spurts of whole brain and the frontal area were seen during the 2 years after birth, (2) after this period, GM volume decreased in both the prefrontal and frontal area, (3) whereas WM volume increased throughout childhood at a slow rate, especially in the prefrontal area, (4) the prefrontal WM volume has not yet maturated to an adult level at seven years old, as in humans. Our findings may uncover key information on human brain development and its relation to functional and evolutionary milestones. [J Physiol Sci. 2008;58 Suppl:S143]

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Humans tend to make illogical inferences, that is, after 'if A then B' (AB) relation was learned, subjects readily infer 'A' from 'B' (BA relation), which animals rarely exhibit. Such an illogical, although not necessarily wrong, cognitive bias may be essential to human highly intelligent functions including language faculty. In this study, we conducted an fMRI experiment to investigate the neuronal correlates of such illogical inference. The subjects were trained with five sets of AB and BC relations to reach the criteria of 90% accuracy before the MRI scans. During scan sessions, subjects were tested with, in addition to trained relations, four untrained and emergent relations; illogical relations of symmetry (BA and CB), their combination (CA), and a logical relation of transitivity (AC). Behaviorally, correct rate were significantly higher than chance level in all emergent relations. Imaging result detected activities in the brain areas both distinctive and common for logical and illogical inferences. The left anterior PFC was activated for logical AC inference, which may contribute to combination of trained relations. The posterior cingulate cortex was activated only for illogical CA inference, which may be involved in the combination of symmetrically emergent relations. The commonly activated areas, right PFC, medial frontal cortex and intraparietal area, may be involved in the process of an abstract category formation which should be made by manipulating relational orders and the categorical discrimination based on the emergent relations. [J Physiol Sci. 2008;58 Suppl:S144]

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Although recent advances in the computer graphics techniques allow us to generate photo-like images, we can distinguish them from real photos. This suggests that an ability to detect the differences between real photo and photo-like images may be embedded in our cognitive system. In this study, we investigated the cortical mechanisms underlying this ability by means of fMRI. Color photographs of human face were modified into painting-like images in five steps. To characterize physical properties of stimulus, the spatial frequency, and the mean changes in color and luminance of each image were calculated. Participants were required to classify the images into one of the five steps(1:photo,5:painting-like image) during fMRI scanning. We found several brain regions, including middle occipital gyrus, middle temporal gyrus, temporo-parieto-occipital junction, parieto-occipital sulcus (POS), fusiform gyrus (FG) and middle frontal gyrus (MFG), were activated during the task. The detailed analysis showed that the activity in the POS and MFG was enhanced when participants evaluate the presented images as more painting-like, while activation in the other regions was correlated with the physical properties of images. These results suggest that the POS-MFG. network may play a crucial role in the detection of differences between real photos and photo-like images. This study was supported by Academic Frontier Project for Private Universities:"Brain Mechanisms for Cognition, Memory and Behavior"at Nihon University:matching fund subsidy from MEXT. [J Physiol Sci. 2008;58 Suppl:S144]

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We have investigated the effect of diffuse color illumination on human brain activity by monitoring EEG. We expected some pattern of diffuse color illumination might have soothing effect on our brain activity level. The light from a number of LED was projected on a white screen which had half-circular shape with the height of 1.8 m. The continuous change of color of emitted light was controlled by a computer. A subject sat in the mid-point of hemi-circle and kept looking at a fixation point. Color was changed continuously along the hue circle (red-yellow-green-cyan-blue-magenta-) for 150 s duration in 2 cycles: rapid (7.5 s/cycle) and slow (15 s/cycle), and in 2 stages of color saturation (hypochromatic and primary colors). EEG was recorded according to the international 10-20 system using EEG-1100 (Nihon Kohden). Eye blinks and movements were digitally cancelled out by Spike2 software (CED). Only theta to gamma regions (4 Hz to 80 Hz) of EEG was analyzed by ATAMAP II (Kissei Comtech). The result from 10 subjects showed that the suppression of alpha and beta, or alpha only or beta only occurred in 7 out of 10 subjects. The luminance of the screen was twice strong with hypochromatic colors and the suppression occurred in the same degree by both color saturation levels, the effect could be resulted from the cyclic color change. Descriptions of subjects when they watched the screen indicated loss of spatial and temporal discrimination, which is different from being in complete darkness. [J Physiol Sci. 2008;58 Suppl:S144]

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When we cannot recall the name of a well-known person despite preserved access to his/her semantic knowledge, a phonological hint such as the initials sometimes helps us to recall. Such recall failure appeared to occur by the transmission deficit from lexical-semantic to lexical-phonological stages in recall processes, and the phonological cue appeared to activate the transmission, leading to successful recall. Using event-related fMRI, we investigated brain regions that respond to the phonological cue. Eighteen right-handed subjects participated in this study. Written informed consent was obtained from all the subjects in accordance with Declaration of Helsinki, and the experimental procedures were approved by the Institutional Review Board of National Institute of Radiological Sciences. We used a 3T MRI system (Signa EXCITE, GE) with GE-EPI. A famous face image was presented with a phonological cue and subjects were required to overtly pronounce the name. The number of correctly recalled trials with first syllable (F) was larger than those with non-verbal sound of a chime (C) and non-first syllable (NF), suggesting that F facilitated name recall. The fMRI results demonstrated that two regions in the left superior temporal gyrus responded more to F than C and NF. In addition, they responded more to the successful recall. These results suggest that they may play a crucial role in the transmission from lexical-semantic to lexical-phonological stages in name recall processes. [J Physiol Sci. 2008;58 Suppl:S144]

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To examine whether acute dynamic exercise could improve cognitive function and the changes in cerebral blood flow of the frontal brain were associated with improved cognitive function, a Stroop color-word test (SCWT) was performed in 12 adults before and after cycling exercise at 20%, 40%, and 60% of maximum voluntary exercise. In SCWT, the subjects were asked to answer a displayed color of a word, which meant "the different color". The total time and the number of errors for 100 SCWT trials were recorded as index of cognitive function. We measured the concentration of oxy-hemoglobin (O₂Hb) in the frontal brain with near-infrared spectroscopy to monitor local cerebral blood flow. 40%- and 60%-exercise for 15 min shortened the total time for SCWT and increased O₂Hb, though 20%-exercise did not alter both of them. The number of error was not altered by any intensity of exercise. The increase in O₂Hb started 5 min after the onset of the exercise and was sustained during and after exercise. When the duration of 40%-exercise was shortened to 5 min, both total time for SCWT and O₂Hb were not altered. These results suggest that acute dynamic exercise at a moderate intensity for a longer period of 15 min, but not 5 min, is able to improve cognitive function and the improved cognitive function may be associated with increased cerebral blood flow of the frontal brain. [J Physiol Sci. 2008;58 Suppl:S145]

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It has been known that the cerebral cortex has an important function to control swallowing movement in humans. Motor and sensory cortices are thought to be dominantly involved in swallowing movement. However, the detail cortical mechanisms underlying swallowing movement in humans are still remained unclear. In the present study, the cortical areas activated by a variety of swallowing tasks such as volitional saliva or water swallowing, jaw, tongue or hand movement in human subjects were precisely analyzed using f-MRI. Eight right handed healthy volunteers were introduced in the present study (4 males, 4 females, age range 27-41 years, mean 33.6±5.5 years). The primary motor cortex (MI), primary sensory cortex(SI) and cerebellum were activated during saliva or water swallowing, jaw and tongue movements. The insula, right middle frontal gyrus, cingulate gyrus and supplementary motor cortex were activated during saliva or water swallowing, or tongue movement. Basal ganglia and left middle frontal gyrus were also activated during saliva swallowing and tongue movement, or during water swallowing, respectively. We also observed that the activation of MI and SI was significantly stronger during saliva swallowing compared with water swallowing. These findings suggest that several cortical regions relating sensory-motor functions are significantly involved in swallowing movement in humans. [J Physiol Sci. 2008;58 Suppl:S145]

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The importance of somatosensory information arising from intraoral mechanoreceptors in intraoral sensory discrimination (e.g. detecting position, consistency, size and shape of an object in the oral cavity) should be stressed, since sensory discrimination in the oral cavity are performed without visual information by nature. Nonetheless, there is little information about how the somatosensory information is processed within the cerebral cortex during intraoral sensory discrimination tasks. For this, many studies showed that visual cortical areas are active during tactile discrimination such as Braille reading and blind discrimination of Mah-Jong tiles both in blind and normally sighted humans. The present study was conducted to investigate if visual cortical areas as well as prefrontal area are activated during intraoral form discrimination task by assessing total ([total-Hb]), oxygenated ([oxy-Hb]) and deoxygenated ([deoxy-Hb]) hemoglobin concentration changes using 44 channel near-infrared spectroscopy (NIRS) in normally sighted humans. Among 12 subjects tested (23-62 years old), increase in [total-Hb] and [oxy-Hb] was observed in visual cortical area in all subjects during the task. Also, such task-related increase in [total-Hb] and [oxy-Hb] in prefrontal area was observed in 8 subjects. The findings suggest that visual cortical areas play important roles in intraoral somatosensory discrimination and somatosensory processing patterns within the cerebral cortex may be variable among individuals. [J Physiol Sci. 2008;58 Suppl:S145]

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To evaluate effects of frankincense odor to human, we analyzed one of the event-related potentials of electroencephalogram (EEG), i.e. contingent negative variation (CNV), electrocardiogram (ECG), heart beat, fluctuation of heart rate and pneumogram. Frankincense odor was applied as vapor to healthy subjects from heated aroma pot onto which 30 maicro-L of the essential oil was dropped. EEG was recorded almost 30 min (5 min control, the first CNV as a control condition for about 6 min, then odor stimulation was started, after 10 min the second CNV as a stimulated condition for 6 min) by Neurofax EEG-1100 (Nihonkohden, Tokyo). Electrode configuration of 25 points on scalp of subjects was based on the 10-10 electrode method by the IEF, International Encephalogram Federation. Averaging of summated EEG data was performed by Eplyzer (Kissei Comtec, Matsumoto). We found that areas of CNV in odor condition were increased on the central region (C3, Cz, and C4) and parietal region (P3, Pz and P4). Heart rate was slightly reduced just after the beginning the odor stimulation. High frequency of heart rate fluctuation (about 4 sec interval, HF) corresponds to an activity of parasympathetic nervous activities. Low frequency of the fluctuation (about 10 sec interval, LF) per HF shows sympathetic activities. We found that the odor activated the parasympathetic activities. Intervals of respiratory ventilation changed depending on each subject during the stimulation. Present results suggested that frankincense odor stimulated concentration and/or expectation of mind in accompanying with an enhanced relaxation. [J Physiol Sci. 2008;58 Suppl:S145]

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EEG related to time dependent varying tasks are signals of non-stational processes, and ordinal information criteria for which stational processes are assumed can not be applied directly. We have proposed an analysis method for EEG signals related to time dependent varying tasks using an information criterion (WMDL) which has been published by one of the authors. By using the method, time dependent varying information amount of a time dependent varying EEG can be evaluated. Tasks performed in this research (II) were observing line drawings of a rounded spiral and a squared spiral whose drawing total time was 17seconds for each. The images of the line drawings were displayed on a CRT display. The subjects were seven graduate students. For measurements of EEG at observations of the images, an electrode cap with 19 electrodes was mounted on the subjects. For two electrodes related to motion activities, the information amount analysis was performed. As the result, on the time axis, most of the information amounts of the EEG signal of the rounded spiral is larger than that of the squared spiral for all seven subjects. For comparison, the information amounts of the primitive images of the line drawings using a Markov model were calculated theoretically and on the time axis, most of the information amounts of the rounded spiral are larger than that of the squared spiral whose information amount is large only at the corners. The important result for the tasks is that the inequality relation between the information amounts of the primitive images is preserved also in the brain signals. [J Physiol Sci. 2008;58 Suppl:S146]

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Objective: The Revised Hasegawa Dementia Scale (HDS-R) is considered as a useful supplementary method to diagnose dementia and to evaluate severity of cognitive disturbance. However, the region of the cerebrum that correlates with HDS-R score is not clear. Recently, a new method was developed to analyze regional cerebral blood flow (rCBF) using a Z score imaging system (eZIS). This system shows changes of rCBF compared with normal database. In addition, a three-dimensional stereotaxic ROI template (3DSRT), fully automated ROI analysis software, was developed. The purpose of this study was to investigate the correlation between rCBF changes and total HDS-R score using these new methods. Methods: The association between total HDS-R score and rCBF changes was investigated in 26 patients (mean age ± SD: 71.8 ± 9.3 years; 7 men and 19 women) with memory impairment using eZIS and 3DSRT. Step-wise multiple regression analysis was used for multivariate analysis, with the total HDS-R score as the dependent variable and rCBF change in 24 areas as the independent variable.Results: Total HDS-R score was significantly correlated only with reduction of left hippocampal perfusion (r=0.61, p<0.01).Conclusion: Total HDS-R score is the important indicator of left hippocampal function. [J Physiol Sci. 2008;58 Suppl:S146]

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Objective: According to a hypothesis of Narabayashi, Goto and Kosaka (1967) based on the effects of thalamic stimulation and lesion during the stereotaxic surgery for Parkinson disease (PD), the nucleus ventralis intermedius (VIM) is involved in the pathology of cogwheel rigidity (CgwR), whereas the ventrolateral nucleus (VL) is concerned with the tonic component of rigidity. In an attempt to test the hypothesis we have confirmed a causal relationship of exaggerated VL β-band electrical activities to the tonic rigidity. In this context we further examined CgwR with the tremor-related VIM activities. Methods: 1) Thirty PD patients gave their informed consent to undergo the thalamotomy. 2) The surface electromyograms (EMGs) were recorded from limb muscles to reveal properties of rigidity. 3) The thalamic activities were led from a bipolar concentric semi-microelectrode (electrical resistance, 50-100 kohm), and monitored as filtered local field potentials and multiple unit spikes. Results: 1) CgwR was induced to muscle stretch with oscillatory activities on EMGs of 5-10 Hz rhythm. 2) The concurrent activities were manifest not on VL β-band activities but on VIM activities with similar coherent frequencies. The frequencies, 5-10 Hz, of CgwR and VIM activities were slightly higher than those of resting tremor of 3-7 Hz in PD, but similar to those of postural or action tremor in essential tremor. The VIM lesion alleviated all these symptoms. Conclusion: The results support the hypothesis by exhibiting the dual nature of pathology of rigidity with tonic and cogwheel components. [J Physiol Sci. 2008;58 Suppl:S146]

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We previously identified inspiratory phase locked alpha oscillation during olfactory stimuli in humans. Electroencephalographic dipole tracing identified their source generators in the entorhinal cortex, hippocampus, amygdala, and orbitofrontal cortex. These areas of activations were needed for process of olfactory recognition and emotion. Recent studies reported that olfactory dysfunction is one of the earliest symptoms of Parkinson's disease (PD). In this study, we used the same protocol in PD patients and compared results of PD with those of age matched controls. All PD patients detected odor, but five out of 10 showed impaired odor recognition. Changes in breathing pattern associated with emotional changes during exposure to odor stimuli were not observed in PD patients. Inspiratory phase locked alpha oscillation waveforms were not observed, however, positive waves followed by negative waves were identified approximately 100 ms after inspiration onset. Dipoles of this component were localized in the entorhinal cortex for odor detection in all patients. The entorhinal cortex may play a crucial role in odor detection, however, decreased activation of the entorhinal cortex, and the limbic areas in PD patients may impair odor recognition. [J Physiol Sci. 2008;58 Suppl:S146]

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Attention deficit hyperactivity disorder (ADHD) is a common behavioral disorder in childhood. Methylphenidate (MPH: Ritalin), a psychostimulant, is widely used drug for the treatment of ADHD as well as attention enhancer in normal adults. Pharmacological studies have shown that MPH blocks dopamine transporter (DAT) and thereby elevates extracellular dopamine (DA) level in mammalian brain. It is hypothesized that these pharmacological actions are relevant to its therapeutic effects whereas underlying mechanisms of the effects remain unclear.Neurochemical mechanisms of the effect of MPH have mostly been studied by using rodents that do not have enough higher cognitive abilities. Thus, we tried to investigate neurochemical mechanisms concerning how MPH elevates extracellular DA, in the prefrontal cortex and striatum of the primate that has much higher cognitive abilities. We first examined effects of MPH on monkeys' cognitive behavior. We trained monkeys on several kinds of cognitive tasks such as delayed response, go/no-go, stop signal and self-control tasks, and examined effects of MPH on monkeys' performance in these cognitive tasks.Oral administration of MPH significantly changed performance of the animal in those cognitive tasks in dose-dependent manner. Especially, clear improvements were observed in the performance of go/no-go and self-control tasks. The results indicate that monkeys could be appropriate models to examine changes in neurotransmitter in relation to MPH-induced cognitive behavior. [J Physiol Sci. 2008;58 Suppl:S147]

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Orbitofrontal cortex (OBF) plays important role in the organization of adaptive behavior. To characterize these functions, single neuron activity was recorded in rhesus monkey OBF 1) during feeding or sexually motivated visual category discrimination tasks and 2) microiontophoresis of neuroactive substances (e.g. glucose, dopamine). The effect of fasting signals on task performance was also tested. Specific feeding- and sex-related firing rate changes were found. OBF neurons showed wide variety of task or category selectivity. Reward- and expectation-related activities were also recorded. In addition, OBF neurons showed complex chemosensitivity to microiontophoretically administered chemicals. Task performance was improved by the i.m. injected fasting-induced endogenous substance 2-buten-4-olide. Our results revealed that OBF is one of the key centers in the organization of adaptive behavior by integrating endo- and exogenous information both on the neurochemical and cognitive level. Supported by Grants-in-Aid for Scientific Research (S.A.), 21st Century COE Program, NRF and HSC of Hungary (T042721, M036687, ETT 315/ and 317/2006), NKTH-RET 008/2005 MEDIPOLIS and Hungarian Academy of Sciences. [J Physiol Sci. 2008;58 Suppl:S147]

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Semaphorins and their receptors have diverse functions in axon guidance, organogenesis, angiogenesis, oncogenesis and immune regulation. Mutations in semaphorin genes are linked to several human neurological diseases, but their actual influence in the pathogenesis remains unclear. To get a clue to the crucial role of semaphorin-triggered signalling in brain homeostasis, we are currently examining the behavioral phenotypes of mice lacking semaphorins and their receptors. Sema4D/CD100 belongs to the class 4 semaphorins, which exhibit crucial roles in growth cone guidance of developing neurons. Our analyses disclosed accelerated motor behavior of Sema4D-deficient mice, suggesting the subtle alterations in the development of various central structures. We also present an aberrant behavioral phenotype of plexin-A1-deficient mice. The mutant mice showed impaired prepulse inhibition of acoustic startle, which is commonly observed in several neuropsychiatric diseases in humans including schizophrenia. Thus the study of the mutant mice may provide a molecular basis underlying the defects of schizophrenia and the related disorders. [J Physiol Sci. 2008;58 Suppl:S147]

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Previous studies reported that we developed a new system comprising continuous wavelet transform (CWT) and artificial neural network (ANN) , and it was effective for the detection of automatic absence-like seizure in long-term electroencephalography (EEG) monitoring. The porpose of this study is to exmine the circadian profile of epileptic seizure using epileptic rats. We measured EEG with the animal model for epilepsy, the Wakaya epileptic rat (WER) . WER is a new mutant exhibiting both spontaneous absence-like behavior and tonic-clonic convulsions. EEG data redorded for three consecutive days were analysed using the system based on CWT and ANN. The frequency of absence-like seizure was greater during the dark period than light period. It was suggested that daily oscillations in the frequency of epileptic seizure might be depended on light and dark cycles. [J Physiol Sci. 2008;58 Suppl:S147]

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Sez12 is a seizure-related gene, which exhibits a down-regulated expression in mouse brain after a pentylenetetrazol-induced seizure. The Sez12 protein is a transmembrane protein encoding the C-type lectin domain in its extracellular region, which is probably involved in cell-cell interaction. Sequence analysis of the Sez12 provided a mouse homologue of the human DGCR2/IDD gene lying within the DiGeorge syndrome critical region, whose hemizygous deletion causes a developmental disorder, termed Velocardiofacial/DiGeorge syndrome (VCFS/DGS). VCFS/DGS patients display malformations in multiple systems, as well as an increased frequency of neuropsychiatric defects including schizophrenia. To examine the physiological and pathological involvement of the Sez12, we generate mice with a deletion in the Sez12 gene. Several Sez12 knockout mice displayed long-lasting seizure-like activity, and abnormal gait and rotarod performance. Histological analysis of these Sez12 knockout mice showed vacuolated perikarya in the Purkinje cell layer, where the expression of the knock-in gene encoding the green fluorescence protein was prominent. However, there was no pathological change in the skeletal muscle involved in some behavioral abnormalities. These findings suggest that the behavioral phenotypes of Sez12 knockout mice are caused by a deficiency of the cell-cell interaction through the Purkinje cells. [J Physiol Sci. 2008;58 Suppl:S148]

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Oxytocin is known as a peptide hormone that causes uterine contruction and facilitates the delivery of the newborn, and stimulates the milk ejection during motherhood. Abundant oxytocin receptors also appear in central nervous system (CNS), especially in limbic system. Oxytocin is involved in the regulation of social behaviors, including maternal care, affiliation and social behaviors in CNS. Moreover, recent studies have shown that oxytocin has anti-anxietic effect during motherhood. However, the exact molecular mechanism is unclear. In the present study, we identified a crucial molecule involved in the regulation of anti-anxiety by oxytocin and regulated the expression by oxytocin. Oxytocin induced the expression of regulator of G-protein signaling2 (RGS2), which is known as a modulator of anxiety, in the amygdala slices of female mice. RGS2 expression in the amygdala of lactating mice was significantly higher than that of virgin mice. Moreover, the expression of RGS2 in virgin mice undergone restraint stress was facilitated compared with that of control mice. And the expression of RGS2 of the group that injected oxytocin antagonist into mice amygdala was significantly lower than that of placebo control group. In addition, RGS2 expression in virgin mice undergone restraint stress with oxytocin antagonist treatment was obviously lower than that with placebo treatment. These results suggest that oxytocin may downregulate anxiety through the induction of the expression of RGS2 gene. [J Physiol Sci. 2008;58 Suppl:S148]

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Lateral hypothalamic orexin neurons project widely through the neuroaxis. One of their target areas is the extended amygdala. We studied the effects of intraamygdalar orexin-A (OXA) microinjections on food and water intake, and emotion- and learning-related behaviors in rats. Bilateral administration of OXA into the intraamygdaloid division of the bed nucleus of stria terminalis (BSTIA) enhanced food and water intake which were blocked by a selective orexin-1 receptor (OX1R) antagonist. In elevated plus maze test (EPM) the time spent on open arms was increased after OXA administration. In EPM and open field tests general motor activity was not changed. In the passive avoidance test OXA increased the transfer latency indicating its enhancing effect on avoidance learning. Analgesic effects of OXA were not found in the hot plate test. We provided evidences for the complex functions of OXA in the BSTIA on food and water intake mediated via OX1Rs, on decrease of anxiety, and on avoidance learning which is supposed to be due to anxiolysis. These data indicate the functional heterogeneity of OXA on feeding behavior, emotion- and learning-related mechanisms. Supported by 21st Century COE program and Grants-in-Aid for Scientific Research (S.A.), NKTH-RET-008/2005 MEDIPOLIS, ETT317/2006, NKTH-OTKA K68431 and HAS (L.L.). [J Physiol Sci. 2008;58 Suppl:S148]

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We have investigated the low dose effects of bisphenol A (BPA) on the central nervous systems such as the sexually dimorphic brain and behaviors, emotion and neuronal activity. Perinatal exposure to BPA disrupted the sexual dimorphism of the size of locus coeruleus (LC) (Kubo et al. 2003). Pre- and postnatal exposure to BPA both impaired the sexual differentiation of exploratory behavior and enhanced depressive behavior (Fujimoto et al. 2006). In addition, the effects of BPA on general motor activity and avoidance response to predator odor and olfactory responses in medial amygdale (MeA) neurons were examined. The smell of fox predominantly suppressed locomotor activity and enhanced avoidance response in the BPA-treated rats. Male MeA neurons showed selective excitatory responses to predator odors. This type of neurons did not respond to plant odors. In contrast, female neurons did not show such selectivity. The sex difference in this neuronal response pattern was attenuated by prenatal exposure to BPA.We hypothesize that anti-androgenic BPA actions are mainly affected on the sexually dimorphic open-field behaviors. In addition, the results suggested that BPA impaired the formations of olfactory neuronal network system which may be due to perinatal gonadal hormone actions. [J Physiol Sci. 2008;58 Suppl:S148]

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Serotonin is considered to play a significant role in anxiety-related behaviors in animals through actions of the median raphe nucleus (MRN) neurons. The habenular nucleus is also concerned with anxiety behaviors, but the connections between MRN neurons and lateral habenular nucleus (LHb) neurons are not yet understood completely. We investigated this point in rats anesthetized with urethane (i.p. 1.5g/kg) anatomically and electrophysiologically: anterograde as well as retrograde tracing methods and extratracellular unit recordings in MRN neurons on stimulation of LHb. Anatomical experiment with injection of fast blue (FB) and fluoro ruby (FR) into LHb and MRN, showed that LHb neurons project to MRN. Stimulation (0.3mA in strength, 0.3ms of duration) of LHb suppressed MRN neurons firing for 25ms to 50ms in post-stimulus time histogram, and stronger stimulation (1mA, 0.3ms) prolonged the duration of this inhibition. Picrotoxin (i.v. 1mg/kg) blocked a later part of the inhibition, but not an early one. Our results suppose that the early inhibitory effect of LHb stimulation is through a direct pathway and the later inhibition via GABAergic interneurons. [J Physiol Sci. 2008;58 Suppl:S149]

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Sensory performance of animals gradually matures as they grow postnatally. This maturation depend on developmental change of not only response properties of single neurons, but also relation among activities of an ensemble of neurons. Here we studied postnatal changes of pair-wise correlation of trial-to-trial fluctuation of responses between nearby neurons in rat primary somatosensory cortex, S1. Using a multi-probe single-shaft electrode, we recorded extracellular activities simultaneously from a group of single neurons that were vertically arrayed across the cortex in urethane-anesthetized rats (postnatal day 5, P5, to P31). Neurons in a rat on P9 showed the greatest positive trial-to-trial correlation (r = 0.78) in their responses to single whisker deflection. Correlation of responses gradually decreased with age and was 0.02 (p < 0.001) on P31. Nearby neurons thus respond to stimuli more independently from others as animals grow up. Because correlation of responses among neurons deteriorates the averaging effect of response fluctuation by pooling of their activities, the results suggest that quality of coding of whisker deflection by an ensemble of neurons increases with development. Correlated activity evoked by sensory inputs in earlier period, on the other hand, may play a role in formation of neural circuits. [J Physiol Sci. 2008;58 Suppl:S149]

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It has been shown that both the amygdala and the insular cortex are important for conditioning taste aversion learning. Anatomically there are reciprocal connections between the insular cortex and the amygdala. However, a few electrophysiological studies on the neuronal networks between of these nuclei have been done. Previously, we reported that spontaneous activity of the insular cortex neuron was depressed after microinjection of glutamate into the amygdala. In the present study, we investigated the changes in neuronal activity in the insular cortex after amygdalar electrical stimulation (train; 100 Hz for 2 sec). At the end of the experiment, the stimulation site was lesioned, electrically. Of the 13 rats, 7 were stimulated within or near the basolateral nucleus of the amygdala. In all cases, spontaneous discharge rate of the insular cortex neurons was depressed after amygdalar train stimulation. In the remaining 6 rats, stimulation sites were located outside of the amygdala. In these cases, spontaneous activity of the insular cortex neurons was unaffected after train stimulation. The data obtained here were similar to those in the chemical stimulation of the amygdala (microinjection of glutamate). These results indicate that excitation of the amygdala depress the activity of the insular cortex neurons. Neural network between the amygdala and the insular cortex may have some roles in the neural mechanisms for the taste aversion learning. [J Physiol Sci. 2008;58 Suppl:S149]

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People can carry out everyday actions nearly automatically. Such habitual actions may become invalid if the environment changes, at which point we need to switch behavior under volitional control. The pre-supplementary motor area (pre-SMA) enables this sort of behavioral switching by first suppressing a habitual action and then facilitating a desired controlled action (Isoda and Hikosaka, 2007). Pathways through which the pre-SMA inhibits or facilitates individual actions remain unknown. To test our hypothesis that the inhibition of habitual action is mediated by the subthalamic nucleus (STN), we studied single-neuron activity as monkeys performed a saccade-overriding task (Isoda and Hikosaka, 2007). We found that successful switching from a habitual to an alternative saccade was associated with a significant change in presaccadic activity for 30% of STN neurons (43/145; "switch neurons"). Such switch-selective activity was direction-selective and emerged mostly when the saccade was to be switched to the contralateral side. In support of our hypothesis, a majority of switch neurons were considered to inhibit unnecessary habitual saccades, which was demonstrated using a saccade GO/NOGO task (Isoda and Hikosaka, 2007). Moreover, while the temporal evolution of switch-selective activity in the STN was early enough to initiate saccade switching, it followed that in the pre-SMA by 16 ms. These data suggest that the STN plays a critical role in inhibiting habitual saccades and the pre-SMA uses the STN to overcome habitual undesired saccades. [J Physiol Sci. 2008;58 Suppl:S149]

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The lateral geniculate nucleus (LGN) of the thalamus conveys visual information to the primary visual cortex. Because activity of LGN neurons is elicited by retinal inputs , amount of LGN activity is expected to represent strength of visual inputs. Thus, visual deprivation is assumed to decrease the LGN activity and induce experience-driven cortical plasticity in young animals. However, it is not clear whether neural activity of the LGN faithfully represents the input strength in awake condition. Therefore, we recorded neural activity in the LGN of behaving rats and examined the influence of visual environments on the LGN activity. Mean firing rate of some LGN neurons was significantly higher in normal light condition than in the dark, while the other neurons exibited similar or rather lower firing rate in the light condition. Thus, the rate of LGN firing does not necessarily reflect the amount of visual inputs. Auto- correlation analysis revealed oscillatory activities in a group of neurons, although we found no significant correlation between the oscillatory activities and the firing rate or light/dark conditions. We further explored the effect of visual deprivation on the firing characteristics of the LGN neurons. [J Physiol Sci. 2008;58 Suppl:S150]

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We studied the microdynamics of pointing accuracy through pen acceleration. Using a pen equipped with a three-dimensional (3D) accelerometer, healthy volunteers pointed to a self-estimated center, at which two oppositely oblique rectangles (each was displayed for 2 sec) intersected at quasi-random intervals (0, 0.5, 2, and 4s), and an unfixed area within a white background on a tablet-PC display. The standard deviation of the pointing distances from the exact center increased in proportion to the intersection interval. In a typical example, the microdynamics of the gripped pen decreased at powers <10 and 40-100 Hz for the last 3 s at an intersection interval of 4 s. We report the relationship between the microdynamics and the pointing accuracy (prediction deviation) for each intersection interval. [J Physiol Sci. 2008;58 Suppl:S150]

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What was the brain for ancient people; did someone think it to be the seat of mind? Yukihiko Kayama and Robert W. Doty Department of Neurophysiology, Fukushima Medical University, Fukushima, Japan Department of Neurobiology and Anatomy, University of Rochester, Rochester, N.Y., U.S.A. The brain is the organ processing various information, producing mental activity or spinning mind. Old Egyptian people did not think the brain to be an important organ; when mummies were prepared, the heart was left in the body and other organs were preserved in a stone box, but the brain was discarded. In the old Greek age, Alkmaion of Kroton (ca 500 BC) proposed that the brain was essential for perception (Doty, Neuroscience 147:561-568, 2007); the idea of the mental premacy of the brain influenced the teachings of Hippokratic school, but virtually slept for two millennia in Europe. In Asia, how did ancient Chinese or Japanese people understand the brain? We inspected meaning of the Kanji of the brain appearing in old literature. In I-shin-poh, the oldest medical book in Japan compiling more than 200 Chinese books, two Kanjis of the brain appeared; both were used to indicate something within the skull (with no meaning of mind). Also in the biggest Chinese-Japanese dictionary (edited by Tetsuji Morohashi) main meaning of the brain is substance, or marrow, within the skull, though in the dictionary a sentence is cited in which a Chinese writer (ca 300 AD) used the brain as a meaning of heart or spirit. [J Physiol Sci. 2008;58 Suppl:S150]

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Astrocytes play various kinds of important roles in such as regulation of neuronal impulse in synapses and maintenance of homeostasis of neurons. Bafilomycin A1, a macrolide antibiotic, reacts to an astrocyte as a specific inhibitor of vacuolar type H(+) pump (V-ATPase) and exert lots of function of astrocytes. Although a bafilomycin A1 has been reported to stimulate secretion of glial cell line-derived neurotrofic factor (GDNF). However, signal tranduction of Bafilomycin A1 in an astrocyte has been yet not elucidated well. Our focus of interest is to explore the signal pathway of bafilomycin A1 in astrocytes. We performed proteomics of human astrocytes stimulated with bafilomycin A1 using both two-dimensional electrophoresis and tandem-mass spectrometry. We found that expression level of cytoskeletal proteins including both cofillin and vimentin, and stathmin in astrocytes has changed significantly. These observations suggest that bafilomycin A1 may exert the function of cytoskeleton proteins. [J Physiol Sci. 2008;58 Suppl:S150]

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The neuronal mechanism underlying trigeminal neuropathic pain was studied in the rats with inferior alveolar nerve (IAN) transection. There is evidence that activated glia contribute to trigeminal neuropathic pain following peripheral nerve injury. However, the underlying mechanism of grial involvement in nerve injury induced neuropathic pain in the trigeminal region is not known. We studied the involvement of astrocytes in neuropathic pain in rats with IAN transection. IAN transection (IAN group) or sham operation (Sham group) was performed in SD rats under adequate anesthesia (50mg/kg, i.p.). Single unit recordings from the trigeminal spinal nucleus caudalis (Vc) were done in IAN or Sham group. Topical administration of fluoroacetate (FA, 1 mM) to the Vc attenuated noxious mechanical and heat responses in IAN group (P<0.05), but not in Sham group. The neuronal responses recovered after local application of glutamine in FA-treated rats. The pERK expression after IAN transection following noxious mechanical stimulation was depressed after the intrathecal (i.t.) administration of FA to Vc (P<0.05). The i.t. application of FA also produced a prolongation of the face withdrawal latency (p<0.01).The present findings suggest that the glutamine-glutamate shuttle in the astroglia is involved in the hyperexcitability of Vc nociceptive neurons, resulting in the trigeminal neuropathic pain following trigeminal nerve injury. [J Physiol Sci. 2008;58 Suppl:S151]

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Trigeminal neuralgia is one of the most common chronic pain syndromes, of which animal model has not been established and etiology is still unknown. We have developed a rat model of trigeminal hyperalgesia produced by a chronic constrictive injury with ligation of the infraorbital nerve. Pain threshold and the pain response scores to the mechanical stimulation were determined in the receptive-field by comparing sham-operated and injured sides. The pain threshold was reduced and the pain response score increased from 1 to 3 weeks and then recovered 4 weeks after injury. By means of in situ hybridization and immunohistochemistry, we found that the Cl- -extruder KCC2 mRNA and protein were downregulated in secondary neurons in injury side of spinal trigeminal nucleus (Sp5). The Cl- importer NKCC1 mRNA was upregulated in the small-sized and large-sized primary neurons in the injured side of the trigeminal ganglion (TG). These significant downregulation of KCC2 and significant upregulation of NKCC1 were observed from 1 to 2 weeks after injury. The results suggest that NKCC1 upregulation in TG may facilitate pain conduction and transmission by autocrine and presynaptic GABAergic depolarizations, respectively. KCC2 downregulation in Sp5 may result in disinhibition by impairing GABA inhibition. Such Cl- homeostatic disruption may increase pain transmission which may underlie the pathophysilology of the trigeminal neuralgia. [J Physiol Sci. 2008;58 Suppl:S151]

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Apolipoprotein E (apoE) affects immune responses and suppresses inflammation in an isoform specific manner. COG133 is a peptide corresponding to residues 133-149 of holo-apoE that possesses the immunomodulatory properties of holo-apoE. In response to lipopolysaccharide (LPS), COG133 significantly down-regulates the release of nitric oxide (NO), IL-6 and TNFa in BV2 microglial cells and in C57Bl/6 mice. These results suggested that we could employ the apoE-peptide, COG133, as a tool to understand how apoE suppresses inflammatory responses. LPS binding to Toll-Like Receptor-4 (TLR4) activates an intracellular signal transduction cascade, which includes phosphorylation of MAP kinases and transcription factors, that eventually participate in stimulating NO and TNFa release. LPS induced phosphorylation of IkB and levels of phospho-IkB were reduced in the presence of COG133. Phosphorylation of IkB is needed to activate NFkB DNA-binding activity and COG133 reduced phospho-IkB levels resulting in decreased NFkB DNA-binding activity. LPS also induced the levels of phosphorylated p38-MAP kinase, ERK and JNK, but the levels of these phospho-proteins were significantly reduced in the presence of COG133 suggesting another site of apoE-peptide action on this inflammatory signaling cascade. apoE peptides corresponding to COG133 were found to bind to cell-surface receptors that bind holo-apoE. We examined the role of these receptors in COG133 function. Independent of the presence or absence of LDL receptors, LPS plus COG133 treated macrophages released significantly less NO than their LPS treated counterparts. [J Physiol Sci. 2008;58 Suppl:S151]

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We participate in the project to establish the technique to detect an injury by shaking for brain in childhood resulted in a nerve disease at the early stage. The aim of our research as the development of method of detecting the injury with the diffusion weighted image by MRI using laboratory animals, evaluating the level of injury by using Fractional anisotropy (FA) and Trace index (TI) obtained from those images. In this presentation, we show the fluctuation of FA and TI values in the image of hippocampus of the brain of infant rat. Diffusion weighted images of hippocampus areas of postnatal 4th to 13th day rat were acquired. The FA value at molecular cell layer (Mol) is higher than that at pyramidal cell layer (Py) and dentate gyrus (DG), and the TI value at DG is lower than others. These results were similar to previous data of adult mouse though a significant conclusion was not obtained. However variations of FA value at Mol and Py that made a peak on the 10th day, and both were significantly different from at DG (two-way ANOVA: DG-Mol P=0.036, DG-Py P=0.028). But TI value at all areas had not show a peak in each day age. These results possibly are related to the expansion of the nerve fiber and the restructuring of the synapse that occur in the infant age rat brain. [J Physiol Sci. 2008;58 Suppl:S151]

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A reliable method to induce neural progenitor/stem cells (NPCs) into dopaminergic (DAergic) neurons as well as the mechanism involved has not yet been established. To induce DAergic differentiation from NPCs, cell cycle blockers in G1/S phase and the factors up-regulated in DA-depleted striatum were used. Treatment of a G1/S phase blocker, desferoxamine (DFO), significantly increased the expression of TGFβ1 mRNA 24 h after the differentiation, while TGFβ2 and β3 mRNAs expression did not change. Treatment of DFO increased the production of trasnforming growth factor beta (TGFβ) followed by nuclear translocation of smad 3, and inhibition of TGFβ signal decreased the number of β-tubulin III-positive neurons. Treatment with the factors up-regulated in DA-depleted striatum (IL-1β, LIF, GDNF, pleiotrophin) increased the number of tyrosine hydroxylase (TH)-positive cells compared with controls. Increases in DA in the medium were confirmed by high performance liquid chromatography. As an increase in hypoxia inducible factor (HIF)-1α protein was found, we investigated HIF-1α effect on differentiation of NPCs to DAergic neurons. Inhibition of HIF-1α caused a decrease in TH-positive cells. Data suggest that neuronal differentiation is induced by cell cycle regulation in G1/S phase mediated by TGF-β and DAergic differentiation was induced by LIF or pleiotrophin mediated by HIF-1α. [J Physiol Sci. 2008;58 Suppl:S152]

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Sodium bisulfite is clinically used as preservative agent for local anesthetics for epidural anesthesia. Some investigators indicate that sodium bisulfite deteriorates local neurotoxicity, while others indicate that it could decrease local neurotoxicity. Previously we reported that the axon of posterior root is most sensitive to local neurotoxicity. Therefore, we examined whether sodium bisulfite increases or decreases local neurotoxicity by estimating axonal flow in cultured mouse dorsal ganglion neurons.I. To determine the uneffective dose of sodium bisulfite on axonal flow, we added either of 0.1 mM, 1 mM, 10 mM, or 20 mM of sodium bisulfite to the axon. Consequently, more than 10 mM sodium bisulfite suppressed the axonal flow and allow the axon to swell, while 0.1 mM of it did not significantly suppress the flow.II. To investigate whether 0.1 mM sodium bisulfite has synergistic effect with local anesthetics, we compared axonal flow after treatment with 1mM procaine alone, 0.1 mM sodium bisulfite alone, and 1 mM procaine plus 0.1mM sodium bisulfite. Consequently, 1mM procaine alone, and 0.1m M sodium bisulfite alone showed 70-80% suppression of axonal flow, while the mixed solution showed 50-60% suppression.The results indicate that sodium bisulfite dose-dependently suppresses axonal flow and may increases local neurotoxicity. [J Physiol Sci. 2008;58 Suppl:S152]

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Neural tissue characteristically contains high proportions of docosahexaenoic acid (DHA) and arachidonic acid (AA). Polyunsaturated fatty acids (PUFAs) play an important role in neuronal development and function, including neurite outgrowth, signal transduction, and membrane fluidity. We previously demonstrated that DHA promoted neurogenesis from neural stem/progenitor cells (NPCs) and increased newborn neuronal cells in rat hippocampus. In other studies, supplementation with DHA and AA enhanced outgrowth of neurite in neuron-like cells and PC12 cells. However, the effects of PUFAs on differentiation of NPCs are not known. This study examined the effect of DHA and AA on proliferation and then on the ration of neurons and astrocytes in the NPCs. NPCs from E14.5 rats were cultured as neurospheres in N2 medium containing basic fibroblast growth factor (bFGF). For differentiation experiments, the cells were cultured in the bFGF-free medium with or without DHA or AA for 1, 2, 4 and 7 days. Cells were fixed, and then immunohistchemical staining using a specific antibody to identify NPCs, neurons and astrocytes. At 7 days in vitro, DHA significantly increased the percentage of neurons and decreased the percentage of astrocytes. [J Physiol Sci. 2008;58 Suppl:S152]

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Hyperphosphorylated tau protein is one of the pathological hallmarks of the brains of Alzheimer's disease patient. Phosphorylation status of the protein has been widely studied by Western blot analysis using phosphorylation dependent antibody. In addition, mobility shift of phosphorylated tau can be used as a manifestation of phospho-tau. We set off SDS-PAGE separation of phosphorylated tau using phosphate-binding tag, dinuclear manganese complex of acrylamide-pendant phos-tag^TM from NARD Institute Itd. In particular, we have studied the modulation of tau phosphorylation by multiple tau kinases including cycline-dependent protein kinase 5 (CDK5). We optimized SDS-PAGE conditions to resolve a mixture of phospho-tau from bovine brain extract. For example, 7.5% of acrylamide gel with 100 μM of Mn²⁺-Phos-tag gave much larger mobility shift than 10% of acrylamide gel without Mn²⁺-Phos-tag. We found that addition of Mn²⁺-Phos-tag in acrylamide gel caused difficulty of transfer to blotting membrane, resulting in poor sensitivity for Western blot analysis. To rescue the difficulty, we decreased methanol content in acrylamide to 10% and used Immobilon^TM-PSQ (0.2 μm) for a blot membrane to get better transfer. Using Mn²⁺-Phos-tag SDS-PAGE, CDK5-phosphorylated tau protein was separated to 3 major bands as a result of mobility shift. The present results suggest that the electrophoretic separation using Mn²⁺-Phos-tag acrylamide was useful to analyze phosphorylation status of tau. Improvement on the blot efficiency must somehow achieve. [J Physiol Sci. 2008;58 Suppl:S152]

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The key portion of the N-terminus of human tyrosine hydroxylase type 1 (hTH1) that affects the stability of the molecule in mammalian cells has not been clarified except for the observation that the sequence up to Ala⁵² is involved. Therefore, this study was performed to map more precisely the N-terminal sequence that predominantly contributes to the stability of hTH1. The results obtained by using N-terminus-deleted hTH1 mutants identified the sequence up to Ala²³ as exerting the effect. Next, in order to clarify the effect, PC12D cells exogenously expressing wild-type hTH1 or the mutants were established. Then, 14-3-3η proteins in the cells were down-regulated by using the RNAi method, because 14-3-3η can bind Ser¹⁹-phosphorylated hTH1. The down-regulation of 14-3-3η proteins in PC12D cells exogenously expressing hTH1 enhanced the stability of the wild-type enzyme and that of the mutant lacking the N-terminus up to Ala²³. However, the stability of the mutant was reduced compared to that of the wild-type enzyme. The stability of the mutant with the N-terminus deleted up to Glu⁴³ was not affected by the down-regulation of 14-3-3η. These results suggest that the 14-3-3η protein regulates hTH1 stability by acting on the N-terminus up to Ala²³. [J Physiol Sci. 2008;58 Suppl:S153]

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Purpose Variability of high frequency (HF) of heart rate power spectrum is known to express the parasympathetic nervous activity in each individual. The other low frequency (LF) is an index of the sympathetic nervous activity that is increased by tilt test, exercise and mental stress load and is known to increase the activity of the sympathetic nervous system. This study shows that LF/HF is a useful index for the evaluation of the stress response in each individual.Method Images for healing, physical fear (on boarding roller coaster), fear, brute, scare and bloodshed movies were shown on the screen of head-up display and ECG of the subjects (six healthy volunteers) was recorded. Power spectrum of R-R interval was analyzed before and after displaying the images, and LF/HF was calculated.Results LF/HF before displaying the images was 4.22±2.86 and it decreased to 1.35±0.80 by the healing image. We noticed that LF/HF in each individual did not show similar common responses to the various images which were expected to stimulate the sympathetic nervous system. However, we could divide the subjects into two groups depending on the change in LF/HF: a group showed no change in LF/HF and the other group showed an increase in LF/HF by the display of the images.Conclusion LF/HF calculated using R-R interval power spectrum is a useful index for the evaluation of the stress response in each individual. [J Physiol Sci. 2008;58 Suppl:S153]

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