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Volume 16 (1966)
- Issue 6 Pages 599-
- Issue 5 Pages 481-
- Issue 4 Pages 363-
- Issue 3 Pages 227-
- Issue 2 Pages 113-
- Issue 1 Pages 1-
Volume 16, Issue 2
Displaying 1-9 of 9 articles from this issue
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Keisuke TOYAMA1966 Volume 16 Issue 2 Pages 113-125
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Impulses discharged from single spindle receptors of frog's sartorius muscle were recorded during stretch at various velocities and their patterns wereanalysedon the basis of a visco-elastic model of the muscle spindle.
2. The model comprises a spring (G2) and a dash-pot (η) in parallel, and a spring (G1) in series with them ; G1 represents the elasticity of the sensory portionof the intrafusal muscle fibres, and G2 and η the elasticity and vis-cosity of the muscular portion, respectively. It is further assumed that the impulse frequency is related linearly to the tension along G1.
3. The spike frequency was measured as Fi before stretch, as Fs at the time when the muscle attained the final length and as Fb long thereafter. In good agreement with the prediction from the model, both Fi and Fb were linearly related to the muscle length at the time of measuring them, while Fd meas-sured as (Fs-Fb) was merely determined by the stretch velocity. The whole time course of the actual spindle response also conformed to that of the ideal response of the spindle model.
4. The parameters of the model were determined by the relations of Fi or Fb versus muscle length and of Fd versus stretch velocity.
5. The actual spindle response differed from the behaviour of the model. in two points: Firstly, the former showed an initial transient rise of the frequency which might be caused by pressure exerted upon the spindle by the neighbouring extrafusal muscle fibres. Secondly, the decay of the spindle discharge at the cessation of stretch was accelerated with an increase of the stretch velocity, which might be due to thixotropic property of the intrafusal muscle fibres.View full abstractDownload PDF (1165K) -
Masaichi SAWA, Naoshige MARUYAMA, Shizuo KAJI, Kyugo NAKAMURA1966 Volume 16 Issue 2 Pages 126-141
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe effect of topically applied strychnine has been studied on pyramidal-and non-pyramidal tract neurons in cats' cerebral motor cortex by means of a micro-electrode technique under barbiturate anesthesia.
In spontaneous activities of the neuron, the most common intracellular potential changes appear to be 1) a progressive increase of depolarizing waves (EPSPs) leading to the formation of long-lasting depolarizing waves (summated EPSPs) and 2) an increase and then a decrease of hyperpolarizing waves (IPSPs) through an advancing course of strychninization. Single shocks to the medullary pyramid have elicited almost the same changes in the responses of the neurons during strychninization.
Our interpretation of the action of strychnine is that it facilitates both the excitatory and inhibitory synaptic transmission and that the excitatory synaptic transmission remains active after the inhibitory one has been blocked.View full abstractDownload PDF (1515K) -
Ichiro TANAKA, Yutaka SASAKI, Hideo SHIN-MURA1966 Volume 16 Issue 2 Pages 142-153
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSOn the excised heart of, Tachypleus tridentatus, the intracellular recording of periodical depolarizations of the cardiac muscle fiber was made simultane-ously with the developed tension and also with the discharges of the dorsal nerve cord.
Spontaneous periodical depolarizations appeared at a rate of about 10/sec corresponding to the bursts of nervous discharges.
Each depolarization lasted about 3 sec and consisted of the initial depo-larization and the subsequent plateau and repolarization phase on which numerous wavelets were superimposed. The resting potential was 30-50 mV.
It was not observed that the depolarization exceeded the zero potential.
Depolarization to a single indirect shock could be recorded in the muscle fiber, and the potential summated to form a sustained depolarization when the repetitive stimulation was applied.
It could be observed that the depolarization during activity had a certain equilibrium potential which seemed to be lower than the zero potential.
From the results it could be concluded that the potential was a synaptic potential at the neuromuscullar junction of the cardiac muscle and that the fiber was multiply innervated.
The junctions would be distributed over the surface of the muscle fiber and the junctional potential developed the tension normally without the pro-pagated action potential.
The potential was extremely enhanced by TEA ion.View full abstractDownload PDF (999K) -
Tadao TOMITA, Teruaki SZAIMI, Naoki TOIDA1966 Volume 16 Issue 2 Pages 154-168
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The electrical response to inward current pulses were studied in the membrane of a single nerve fiber of the crayfish, Procambarus clarkii, depolarized by KCl.
2. The hyperpolarizing response was observed at a critical membrane potential producing a hump or repetitive and spike-like potential.
3. Cessation of a second inward current pulse during conditioning hyper-polarization caused break-depolarization and, at a critical intensity, a slow depolarizing response.
4. The electrical responses observed in this membrane could be mostly explained in terms of changes of the membrane resistance.View full abstractDownload PDF (1146K) -
Masayosi GOTO, Yosiko KIMOTO1966 Volume 16 Issue 2 Pages 169-184
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Introducing a universal tensile testing instrument into medical investigation, cyclic stretch and release and stress-relaxation tests were performed on the excised walls of the toad aorta and vena abdominalis.
2. Hysteresis loop of the aorta was far less remarkable than that of the vena abdominalis as expected. Changes in the initial length setting affected. the ascending limb of the hysteresis and that of the final length, the descending limb, in such a way that an increase of the setting length caused an increment of the steepness of respective limbs.
2. Changes in the loop under variable conditions such as the rate, number and interval of the cyclic stretch with a ‘definite amplitude’ were mainly produced by alteration of the ascending limb, while the descending limb appeared rather stable.
4. Electrical stimulation of the vessels enhanced the hysteresis loop and its steepness mainly elevating the ascending limb. Formic acid digestion of the vessels produced a decrease of elastic modulus and a dramatic disappearance of the hysteresis, whereas trypsin digestion caused an increase of the former accompanied by a considerable size of hysteresis.
5. Thus, the ascending limb seems to relate mainly to the muscle function, the descending upper half limb to the collagen and the lower half to the elastin elements.
6. Stress-relaxation curves for different grades of stretch were analysed into three component periods from the distribution functions, i. e. the initial, middle and last rising phases. Comparison of the normal distribution functions to those of formic acid and trypsin treated ones clarified that the collagen element played a main role at the initial phase, the muscle at the middle and the elastin at the last phase.View full abstractDownload PDF (3815K) -
Sosogu NAKAYAMA, Hiroyuki FUKUDA1966 Volume 16 Issue 2 Pages 185-193
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. In dogs anesthetized with pentobarbital sodium the intravenous administration of 0.5 to 1 Ivy dog unit/kg CCKV (Cecekin Vitrum) produced the excitation of the movements of the gall bladder, stomach and small intestine. After the administration of atropine or hexamethonium the excitatory effect was not abolished.
2. The motility of the isolated duodenal loop of a rabbit was increased by the administration of CCKV. The excitatory effect of the agent on the excised muscle strip of the dog jejunum was less than that in the rabbit intestine.
3. On the other hand, about 1.5 minutes after purfusing the lumen of the isolated jejunum with N/10 HCl solution, the gall bladder began to contract and several minutes later the contraction reached its maximum, while there occurred no response in the jejunal movements.
4. From the results described above it may be concluded that pure cholecystokinin exerts no effect on the motility of the small intestine, and that a potent preparation of cholecystokinin (Cecekin Vitrum) is not a purified cholecystokinin, but it contains some unknown substance to excite movements of the small intestine and stomach.View full abstractDownload PDF (738K) -
Jihei KONISHI, Masahide UCHIDA, Yukiko MORI1966 Volume 16 Issue 2 Pages 194-204
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Electrical responses of the taste receptors of the lips in sea catfish (Plotosus anguillaris (LACÉPÈDE)) to various taste stimuli were studied by recording from single facial nerve fibers.
2. In addition to tactile fibers, the facial nerve innervating the barbels contains fibers which respond specifically to passive bending of the barbels. The extremely high sensitivities of barbels and lips to mechanical stimuli and the bilaterally symmetrical innervation of the facial nerve branches suggest that the tactile and the above-mentioned pressure receptors may subserve rheotropic orientation of this fish.
3. Study of single taste fiber responses showed that taste receptors of this fish could respond to NaCl, quinine and acid dissolved in seawater. Many of these single fibers responded to more than one kind of taste stimulus, but in different degrees showed a variety of individual responses. Sucrose did not produce any appreciable response in the fish tested. The stimulation effectiveness of distilled water was rather inconspicuous. We noticed highly specific responses to NaCl and to acid.
4. A fiber which responds strongly to extract of marine worm was frequently found. This fiber was commonly stimulated by blood sera of other animals and sometimes by human saliva, milk, lecithin and betaine. It seems probable that sea catfish may have highly specialized taste receptors responding to gustatory-attractive substances.View full abstractDownload PDF (10185K) -
Kyoji TASAKI, Keishiro KARITA1966 Volume 16 Issue 2 Pages 205-216
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The ERG of the octopus and squid was studied when a plane polarized light was rotated. The direction of electric vector was expressed by the angle of deviation from the standard direction of the retina, the horizontal axis of the retina.
2. There was no differential response with respect to the simple rotation of the polaroid.
3. If the retina was pre-illuminated by polarized light of which e vector was at 45°, still no differential response was noted.
4. Pre-adaptation at around 0°(angle of deviation of e vector of adapting light from the standard direction was less than 45°) caused maximum suppression (minimum response) at 0° and 180°, and minimum suppression (maximum response) at 90° and 270° of test lights.
5. Pre-adaptation at around 90°(e vector was between 45° and 135°, except. at 45° and 135°) gave the opposite result.
6. These results suggest that in the cephalopod retina there are only two, sensitive planes which are maximally sensitive to either horizontal or vertical vector-component of the incident light.
7. These sensitive planes could well be analyzers which can discriminate e vectors between horizontal and vertical but not between 45° and 135°.
8. The morphological basis was considered and it was concluded that the horizontal-vertical organization of the rhabdomeres is the mechanism for polarization analysis.View full abstractDownload PDF (1132K) -
Kisou KUBOTA, Yoshiaki KIDOKORO1966 Volume 16 Issue 2 Pages 217-226
Published: 1966
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSExcitability of the single motor neuron was tested by stimulating directly the lumbar cord in unrestrained and unanesthetized cats, and was compared between sleeps with slow wave and spindle burst in EEG (slow wave sleep) and sleep with low voltage fast wave in EEG (activated sleep). During the latter, the threshold to elicit the single motor unit by the direct excitation of the motor neuron increased in both hind-limb flexors and extensors.View full abstractDownload PDF (3124K)
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