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Volume 28 (1978)
- Issue 6 Pages 721-
- Issue 5 Pages 557-
- Issue 4 Pages 401-
- Issue 3 Pages 249-
- Issue 2 Pages 109-
- Issue 1 Pages 1-
Volume 28, Issue 2
Displaying 1-10 of 10 articles from this issue
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Sadayuki F. TAKAGI, Masae IINO, Hiroshi YARITA1978 Volume 28 Issue 2 Pages 109-128
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSEffects of various gustatory stimulants upon the olfactory epithelia were examined in the olfactory bulb of the bullfrog and the carp.
1. The olfactory epithelia of the two animals responded to the salty, bitter- and acid-tasting substances, but not to the sweet ones.
2. The olfactory epithelium of the bullfrog responded immediately to sodium solutions of high concentrations (the “initial response”), but the response to those of low concentrations showed long latency (the “delayed response”). In the carp, the “initial response” was found, while the “delayed response” was not in most cases. A “negative” delayed response was found only infrequently.
3. Responses only to high alkali or acid solutions were found in the two animals.
4. When 0.05 M NaCl was added to HCl solutions, an enhancing effect was found in the bullfrog, while a reducing effect occurred in the carp. On the contrary, when 0.05 M NaCl was added to NaOH solutions, an enhancing effect occurred in the carp, while no consistent result was found in the bullfrog.
5. Many amino acids were effective stimuli in the bullfrog, but only betaine and 1-aspartic acid were found effective in the carp.
6. Changes in temperatures beyond 35°C or under 10°C elicited responses. Mechanical stimuli were effective in the carp, but not in the bullfrog.
7. The “water response” was found in the bullfrog, but not in the carp.
8. Sensitivities of the olfactory epithelia of the two animals were compared and discussed.View full abstractDownload PDF (2272K) -
Sadayuki F. TAKAGI, Masae IINO, Hiroshi YARITA, Kensaku MORI1978 Volume 28 Issue 2 Pages 129-148
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe stimulating effects of mono- and divalent cations and anions were studied in the olfactory epithelia of the bullfrog and the carp. The rhythmic waves induced by these ions were recorded in the olfactory bulb.
1. Many mono- and divalent cations and anions showed stimulating actions in the bullfrog and the carp.
2. Microelectrode studies disclosed that the olfactory receptor cells respond to different ions differently.
3. When many ions were applied with various concentrations, responses appeared with long latencies while the concentration was very low (the “delayed responses”). The responses nearly disappeared at the intermediate concentrations, but then responses with short latencies appeared at the higher concentrations (the “initial responses”). Thus, many ions showed dual responses in the bullfrog, although some exceptional cases were found (choline+, Tl+, La3+, Cd2+)
4. Cd2+ and other heavy metal ions showed depressive actions upon the responses induced by other ions in the olfactory epithelium.
5. Tetrodotoxin of even 10-5 g/ml was found ineffective in depressing the rhythmic waves induced by ions.
6. Chemoreceptive activities of the olfactory epithelia of the bullfrog and the carp were compared with the activities of the gustatory receptors. They were also compared with the other chemoreceptors of the fish, namely the palatal organ, external chemoreceptors over the snout region and the lateral-line organ. Chemical senses of the fish were discussed.View full abstractDownload PDF (2061K) -
Masae IINO, Sadayuki F. TAKAGI1978 Volume 28 Issue 2 Pages 149-157
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe olfactory epithelia of the bullfrog and the carp were stimulated with various odorants in the gaseous and/or aqueous phases. Some ionic solutions were also applied.
1. By recording the induced waves in the olfactory bulb, it was shown that the bullfrog responds to odorants in the two phases, but the carp can respond only to odorants in the aqueous phase.
2. Comparison of the stimulative effects of the same odorants in the two phases were made in the bullfrog. Although various response patterns to gaseous and aqueous stimuli of single cells in the olfactory bulb were found in most cases, a difference in the application methods of vapors and solutions made such comparison difficult.
3. The same single cells in the olfactory bulb usually responded to various odorous vapors and solutions as well as to ions in different patterns. When the responses to the vapors and solutions of the same odorants of different concentrations were compared, different patterns were also found.View full abstractDownload PDF (953K) -
Ken-ichi HONMA, Tsutomu HIROSHIGE1978 Volume 28 Issue 2 Pages 159-169
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSSimultaneous determination of the circadian rhythms of locomotor activity and body temperature was carried out in the rat. Deep body temperature was monitored continuously using a telemetric device. The circadian rhythm of locomotor activity was characterized by clustering of several bursts of activity during the dark period. The circadian rhythm of body temperature was also characterized by bursts of small fluctuations which were well correlated with those of locomotor activity. Correlation between the two functions was such that the regression line expressing body temperature as a function of locomotor activity had approximately the same slope for dark and light periods, but a body temperature for a given amount of locomotor activity was significantly higher during the dark period than during the light one. After a prolonged exposure to constant light, the circadian rhythm disappeared in both functions. Both showed bursts of fluctuations which were correlated with each other. These results indicate that the bursts of body temperature increment were dependent on those of the locomotor activity. However, manifestation of the circadian rhythm per se of body temperature could not be explained as resulting exclusively from the circadian fluctuation of locomotor activity.View full abstractDownload PDF (1120K) -
Emiko ADACHI1978 Volume 28 Issue 2 Pages 171-180
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSScotopic properties of the peripheral retina in man was studied by recording visually evoked cortical potentials (VECPs).
The intensity required for a criterion latency of the scotopic VECP was compared with the sensory threshold in a number of situations where the stimulating retinal site and the area of the stimulus were altered. With circular spot stimulation, the VECP amplitude attenuated greatly as the stimulus site moved to peripheral 10° and was almost null when stimulation was made outside it. However, within the retinal area from the fovea to peripheral 10°, the VECP sensitivity was found to vary according to the rod distribution, as suggested from the sensory threshold. Stimulation with annular patterns revealed that the parallelism between the VECP sensitivity and the rod distribution holds good within up to 30° from the fovea. A strong summation was proved to be operative for eliciting VECPs by stimulation of the peripheral retina.View full abstractDownload PDF (1019K) -
Takahiro KUBOTA, Mamoru FUJIMOTO1978 Volume 28 Issue 2 Pages 181-196
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn order to examine the seasonal changes in the relationship between the membrane potential and potassium activity of proximal tubular epithelium, a micropuncture study was performed with potassium selective microelectrodes on the kidney of the bullfrog (Rana catesbeiana) in two different seasons: winter (7°) and summer (20°).
The potassium activity in winter animals (7°) was 2.92±0.33 (mean± S.D., n=20), 63.2±12.7 (n=26), and 2.68±0.19 (n=26) mM for the tubular fluid, cell, and plasma, whereas that in summer animals (20°) was 2.84±0.05 (n=22), 61.8± 11.2 (n=24), 2.63±0.24 (n=24) mM, respectively, indicating no seasonal difference. On the other hand, the mean values of the membrane PD in winter animals were 59.4±1.8 (n=26) and 71.7±7.2 (n=26) mV for the luminal and peritubular borders, whereas those in summer animals were 55.1 ± 1.7 (n=24) and 63.9 ± 6.9 (n=24) mV, respectively, indicating that there was a significant seasonal difference (p<0.05 and p<0.001). Hence, compared to winter animals, the changes in the electrochemical profile for potassium in summer animals were: 1) the peritubular membrane PD is lower and 2) the transtubular electrochemical gradient is less steep. The sodium permeability calculated as the best fitting for a modified Goldman equation was 0.01 and 0.03 for winter and summer animals, respectively.
In view of the fact that potassium in the cell and luminal fluid of the proximal tubule is kept at similar levels, potassium homeostasis is maintained in both groups of animals. The seasonal changes in electrical potentials are probably be due to an increase of cellular membrane permeability to ions other than potassium and to increased paracellular shunt conductance through the epithelium.View full abstractDownload PDF (1767K) -
Takuro OSA, Toshio FUJINO1978 Volume 28 Issue 2 Pages 197-209
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe membrane activities of the longitudinal and circular muscle bundles of rat uteri were recorded with a single sucrose gap method, using animals at various stages of the estrous cycle, pregnancy and after ovariectomy. In the longitudinal muscle during estrus, an initial plateau potential was followed by a slow potential. During diestrus and metestrus, an asynchronized action potential composed of plateau and a slow potential were exhibited. The action potential re-corded in uteri taken out of an ovariectomized animal or during early pregnancy was similar to that of uteri during diestrus and metestrus. The circular muscle during estrus gave a plateau potential similar to that of the longitudinal muscle. During diestrus, metestrus, early pregnancy and in the ovariectomized uterus, the membrane activity of the circular muscle was decomposed to produce small plateaus.
The spike activity took place in the longitudinal muscle after mid-pregnancy. The slow potential was dominant in the circular muscle during mid-pregnancy, while spikes were progressively generated toward term. Those differences of membrane activity between the longitudinal and circular muscle bundles were discussed in relation to the endogenous change in the sex steroid hormones.View full abstractDownload PDF (1255K) -
Effects of Low Temperature on the Membrane Currents and Tension Components of Bullfrog Atrial MuscleMasayoshi GOTO, Yasuo TSUDA, Atsuko YATANI, Masahiko SAITO1978 Volume 28 Issue 2 Pages 211-224
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn order to clarify the nature of inotropic action of low tempera-ture, the effects of cooling on the membrane currents and tension com-ponents were studied on the bullfrog atrial muscle under voltage clamped and unclamped conditions with double gap method. Cooling (in between 35°-7°C) produced an increase of overshoot and a prolongation of the action potential accompanied by a slight depolarization of the membrane, a decrease of basal tension and an increase of twitch contraction. Under voltage clamp, a marked augmentation of contraction also occurred despite a decrease of basal tension, suggesting that the inotropic effect of cooling is not merely dependent on the prolongation of action potential. When the components of membrane current and tension were isolated in modified Ringer solutions, it became clear that ICa and ICa-dependent tension markedly increased at low temperature, while all other currents (INaf, INas, IKl, Ix) and ICa-independent tension decreased. Leaky mem-brane current (Il) for hyperpolarizing pulses also diminished. Tempera-ture coefficient (Q10) of the ICa-independent tension component was 1.2-1.5 between 7°C and 17°C, while that of ICa-dependent tension varied depending on depolarization voltages. These data were discussed in relation to possible alteration of Ca concentration at outer and inner layers of the membrane which may depend on temperature.View full abstractDownload PDF (10121K) -
Kohtaro KAMINO, Akira INOUYE1978 Volume 28 Issue 2 Pages 225-237
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSChanges in the fluorescence intensity of merocyanine-540 were measured in suspensions of synaptic plasma membrane ghosts isolated from rat brain cortex. With preincubation of the membrane ghosts in isotonic KCl or NaCl solution, K- and Na-enriched ghosts samples were prepared. In suspensions of both sort of synaptic membrane ghosts, merocyanine-540 showed a fluorescence emission peak at a wavelength of 590 nm.
Under a fixed total concentration of NaCl and KCl, high external K+ induced an increase in the fluorescence intensity, such an increase being proportional to logarithm of K+ concentration. Replacing K+ by Rb+, NH4+ or Cs+, a similar effect was observed. Rb+ was about as effective as K+; NH4 is about 2/3 and Cs+ 1/4 as effective. But the changes in fluorescence with increasing K+ concentration were larger in K-ghosts than in Na-ghosts. K+-induced fluorescence changes were very small when gramicidin D was added to the suspension. K+-induced fluorescence changes were not observed in ultrasonicated ghost suspensions. Such findings seem to indicate that the K+ -ions induced fluorescence increases reflect the depolarization in the isolated synaptic plasma membrane ghosts. Furthermore, the permeability ratio PNa/PK(PNa, PK: the permeability constant for Na+ and K+) was estimated to be smaller than 0.03.View full abstractDownload PDF (4257K) -
Takehiko SEMBA, Tsuyoshi MIZONISHI1978 Volume 28 Issue 2 Pages 239-248
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe atropine-resistant contraction of the alimentary canal, first reported by CAMPBELL (1966) and subsequently confirmed by others, was examined in dog in vivo. The gastric and colonic motor excitations were examined by stimulating the extrinsic nerves, the medulla oblongata or the spinal cord and its roots. Prolonged stimulation of the vagus, medulla oblongata or splanchnic nerve, thoracic cord and its dorsal root produced excitation of the gastric motility even after intravenous injection of sufficient atropine, although the intensity and frequency of peristalsis were slightly reduced. Prolonged latent periods were characteristic of the atropineresistant excitation in the stomach, the latency being 29.8-49.4 sec as compared to 2.3-14.5 sec in control (without atropine). On the other hand, the colonic excitation induced by the stimulation of the pelvic nerve, or sacral cord and its ventral root was not inhibited by atropine; no prolongation in latency and reduction of peristalsis was observed.View full abstractDownload PDF (1023K)
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