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Volume 18 (1968)
- Issue 6 Pages 687-
- Issue 5 Pages 563-
- Issue 4 Pages 403-
- Issue 3 Pages 267-
- Issue 2 Pages 145-
- Issue 1 Pages 1-
Volume 18, Issue 2
Displaying 1-10 of 10 articles from this issue
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Kohsi TAKANO, Saburo HOMMA1968 Volume 18 Issue 2 Pages 145-156
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Vibratory stimuli from 25-500c/s were applied to the cat's triceps surae muscle. The group Ia discharge from the muscle spindle was obtained from the dorsal root filament.
2. The new term “response ratio”, which shows the number of spikes res ponding to one cycle of vibration, was used and this ratio observed at every vibratory frequency.
3. There were sometimes a few gaps or valleys in the response's ratiofrequency curve, the frequency of which showed simple integral relations, such as one to two or two to three.
4. The discharge patterns at every frequency changed in a staircase manner.
5. It was discussed that these phenomena may be due to the physical properties of each muscle spindle.View full abstractDownload PDF (1197K) -
Hiroshi IRISAWA, Akinori NOMA, Ritsuko UEDA1968 Volume 18 Issue 2 Pages 157-168
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe oyster heart muscle can continue to develop spike potential rhythmically in a solution where practically all Na ions were removed and replaced by isosmolar Tris. Tetrodotoxin did not show any appreciable effect on both contraction and excitation at the concentration of 5×10-7g/ml. The application of 10mM manganese ion caused the frequency to increase, but after 30 minutes the rhythmical contraction stopped at a diastole with a concomitant cessation in electrical activity. The amplitude and maximum rate of rise of spike potential which developed in Na+ free solution increased as the concentration of Ca++ in the solution was elevated and decreased when it was reduced. A tenfold increase in [Ca++] 0 elevated the amplitude of the spike potential by approximately 19mV. This indicates that Ca++ can also play a dominant role in the generation of spikes in the bivalve heart muscle.View full abstractDownload PDF (1285K) -
Takeshi ENOMOTO, Kazuko FUKUOKA, Yasuo IMAI, Makoto KAKO, Yoshiyasu KA ...1968 Volume 18 Issue 2 Pages 169-178
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1) In the unanesthetized chronic cat the monosynaptic reflex responses were recorded from the masseter nerve or from the masseter and temporal muscles, after giving shocks to the trigeminal mesencephalic tract.
2) In the para-sleep phase the monosynaptic reflex response was smaller than in the preceding ortho-sleep phase. Transient facilitation and depression were also found during para-sleep. Threshold for the reflex elicitation increased slightly during para-sleep.
3) In awake relaxed state the reflex response was not larger than that of ortho-sleep.View full abstractDownload PDF (1006K) -
Tsutomu HIROSHIGE, Haruhiko KUNITA, Keiichi YOSHIMURA, Shinji ITOH1968 Volume 18 Issue 2 Pages 179-189
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSAn assay method for corticotropin releasing activity was described. In this method, use was made of direct microinjection of test materials into the adenohypophysis, exposed parapharyngeally, of dexamethasone-Nembutal blocked female rats. Possible spread of the injected materials to nearby neural structures was excluded by studying the distribution of 86Rubidium solution after intrapituitary injection. The adrenal and pituitary responsiveness of the assay animal was found to be sufficiently high. By use of this assay method it was shown that acetic saline extracts of the median eminence and posterior pituitary lobe of the rat exhibited a significant CRF activity, whereas nia detectable activity was observed in those of the brain cortex, midbrain and plasma.
It is proposed that direct microinjection. of test materials into the parapharyngeally exposed pituitary is a reliable and practical assay method for CRF activity.View full abstractDownload PDF (1072K) -
Yosizumi NIIMI, Kisou KUBOTA, Yoshiaki IWAMURA1968 Volume 18 Issue 2 Pages 190-197
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSBoth spontaneous and evoked GSRs were compared at different phases of the sleep (para-sleep and ortho-sleep) in unrestrained chronic cats. The GSRs were recorded from the forelimb paw pads, using zinc with zinc sulphate electrodes.
In 68 percent of 81 cases with 13 cats the number of spontaneous GSRs decreased during the para-sleep phase rather than during ortho-sleep phase, while in 32 percent it increased. The increased cases were characterized by a burst pattern composed of continuous small potentials continuing for 5 to 60 sec.
In the ortho-sleep phase, stimulation of peroneal nerve fibers evoked GSRs occasionally, while in the para-sleep phase, periods of complete silence and/or those of successive evocations appeared alternately.View full abstractDownload PDF (660K) -
Kisou KUBOTA, Yoshiaki KIDOKORO, Jiro SUZUKI1968 Volume 18 Issue 2 Pages 198-215
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. In the decerebrate cat, an IPSP was recorded intracellularly in the moto-neurons of jaw-closing muscles and of lumbar flexor and extensor muscles after single shocks applied to the lowest threshold afferent fibers of the super-ficial radial nerve of both sides.
2. The trigeminal IPSP had a latency of 8.5 msec, a rise time of about 5 msec and a decay time of about 30 msec. The lumbar IPSP had a latency of about 40 msec, a rise time of about 40 msec and a decay time of about 60 msec.
3. When the monosynaptic reflexes of the masseter nerve and from peroneal or gastrocnemius-soleus nerve were conditioned by a superficial radial nerve, the depression of similar time course to the IPSP was seen. Evidence is shown that the presynaptic inhibitory mechanism is not involved in the depression of lumbar monosynaptic reflex activities.
4. The polysynaptic reflex, evoked by the inferior dental nerve shock, and recorded from the nerve to the anterior belly of the digastric muscle and the mylohyoid muscle was depressed by the superficial radial nerve shock, having a similar onset and rise time to the masseteric monosynaptic reflex depression.
5. Interactions with the intracellular monosynaptic EPSP and cutaneous IPSP were studied in the trigeminal motoneurons.View full abstractDownload PDF (1837K) -
Katsuhide NISHI1968 Volume 18 Issue 2 Pages 216-231
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Changes in the threshold of the Pacinian corpuscle for mech anical stimulation by perfusion with Na-free solution, Li solution and solutions of varying K and Ca concentrations respectively were measured.
2. After perfusion of the corpuscle with Na-free solution the threshold in-creased first and the initiation of impulses was abolished withi n 8 min after perfusion. The impulse reappeared immediately after replacing Na -free solution by the normal one, the threshold returning to the initial value within 3.6 min. 3. Li solution caused an increase in the threshold and abolished the impulse within 22 min after the onset of perfusion, the recovery time being about 30 min, while nerve fibers supplying corpuscles lost their excitability after 90min in Li solution.
4. Perfusion with solutions of low K content and K-free solution produced a slight increase in the threshold, while with 11.2 mM KC1-solution the threshold was decreased. Perfusion with 28.4 mM KCl-solution caused a marked increase in the threshold and abolished the impulse
5. By perfusion with low Ca solution a threshold decrease was obse rved and with Ca-free solution the impulse initiation was maintained for 1 hr, while Ca-free solution containing EDTA blocked the impulse. Effects of EDTA were reversible. With increasing Ca concentration in the perf using solution the threshold increased and in 108 mM Ca-solution the impulse initiation was abol-ished.
6. It is concluded that Na and Li ions are mainly responsible for the gener-ation of the receptor potential but Ca and K ions may not affect the receptor potential directly.View full abstractDownload PDF (1553K) -
Masayasu SATO, Masahiro OZEKI, Katsuhide NISHI1968 Volume 18 Issue 2 Pages 232-237
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe receptor potential of the non-myelinated terminal of Pacinian corpuscles, of which the lamellae had been almost removed, was recorded in normal saline and Na-deficient solutions. Af ter replacement of the saline solution immersing the terminal by choline solution the receptor potential amplitude is reduced gradually to 25-50% of the original value in 60-90 min, the time course of the reduction being much slower than that obtained by perfusion of the corpuscle. Replacement of the saline solution by Li solution caused a decrease of the receptor potential to 70% of the original value in 60-90 min. The difference in the time course of the reduction in the receptor potential in Li solution from that in choline solution indicates that Li ions can substitute for Na in generating the receptor potential. The decrease in the receptor potential in Li solution has been attributed to accumulation of Li ions inside the terminal.View full abstractDownload PDF (605K) -
Masayosi GOTO, Yasuji SAKAMOTO, Hiroshi KAWATA1968 Volume 18 Issue 2 Pages 238-255
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1) Continual premature extra-activations produced a marked increase in rate of isometric tension development and peak tension of regular contraction in the isolated guinea-pig atrium without altering the duration of contraction and relaxation times.
2) The potentiation always appeared when transmembrane action potential (AP) was elicited by extra-stimuli, and never when AP failed. However, absence of change in resting potential and decrease in height, duration and rate of rise of regular APs all failed to give proper explanation of the potentiation.
3) Analyses of the frequency-strength relationship and degree of activation showed a marked enhancement of PIEA, slight increase in NIEA and no alteration of RSC during extra-activation potentiation. Thus, the enhancement of PIEA in the excitation-contraction coupling process was established as a main cause of the potentiation.
4) Ca++-excess solution, caffeine and thymol inhibited the grade of potentiation, while solution containing no Ca++ enhanced the potentiation. Sucrose hypertonic solution caused a peculiar inhibition instead of potentiation, and a rebounding accentuation of contraction, after onset and cessation of premature extra-activations respectively. Hypotonic solution produced reversal phenomena mixed with the known effects of NaCl-deficiency.
5) These facts suggest that Ca++-release and uptake by the tubular systems are closely associated with the changes of PIEA and NIEA and play fundamental roles in the production of premature extra-activation potentiation (or inhibition).View full abstractDownload PDF (1955K) -
Yosiko KIMOTO, Masayosi GOTO1968 Volume 18 Issue 2 Pages 256-265
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1) The mechanical characteristics of the toad blood vessels were investigated under different pHs using a dynamic strain amplifier.
2) The resting tension of the vessels had three peaks at pH 2, pH 5 and pH. 12, and in the range between pH 3 and pH 10 decrease slightly when the pH was altered in either direction from 7.4.
3) Active tension was developed between pH 3 and pH 11, and reaching a maximum level at pH 9.
4) In solution made hypertonic by adding sucrose, the active tension and the peaks in the resting tension at pH 5 and pH 12 disappeared. Furthermore, . the peaks in the resting tension at pH 5 and pH 12 were irreversible. Therefore, it was established that the peaks in the resting tension at pH 5 and pH 12 were due to acid and alkali contractures of the muscle component.
5) Vessels, treated with crude trypsin, so that only the collagen component remained functional, showed acid contracture at pH 2 and slight alkali contracture at pH 12, supporting the conclusion that the peak in the resting tension of the vessels at pH 2 was mainly due to the collagen component and that at pH 12 partly due to the collagen component.
6) Vessels digested with formic acid, so that only the elastin component remained functional, showed an almost constant response at different pHs over a wide range, but when out of this range, the resting tension decreased, the decrease being more rapid on the alkaline side.View full abstractDownload PDF (895K)
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