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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 4
Displaying 1-13 of 13 articles from this issue
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Hidenobu MASHIMA, Hiroshi WASHIO1968 Volume 18 Issue 4 Pages 403-416
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The changes in membrane potential of frog semitendinosus muscle produced by AC or repetitive pulses were investigated with intracellular microelectrodes.
2. At 100-500c/sec, responses evoked by AC or repetitive pulses were separated into successive three phases;the phase of spike potentials, the phase of alternating spike and local responses and the phase of summated local responses.
3. The first two phases were shortened with increasing frequency but the third phase lasted considerably long without fatigue. Each phase in AC stimulation was longer than that in pulses stimulation, provided with the same frequency.
4. The absolutely refractory period was apparently shortened when the hyperpolarizing current was applied before the test pulse.
5. During the phase of summated local responses, the membrane potential showed the steady depolarization of 20-30mV for pulses stimulation and the mean depolarization of 30-40mV for AC stimulation.
6. The amount of mean depolarization during AC stimulation was almost independent of the resting potential between 50-70mV or the intensity of the current examined.
7. No rectification or no capacitance change was observed during AC stimulation.View full abstractDownload PDF (8225K) -
Hidenobu MASHIMA, Hisako TSUCHIYA1968 Volume 18 Issue 4 Pages 417-431
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The mechanical response of frog's semitendinosus muscle generated by AC or SP at various frequencies and intensities were studied, referring to the electrical changes in membrane potential described in the previous paper.
2. The AC stimulation generated the early tetanic contraction due to propagating spike potentials and the late contracture response due to non-propagating local responses. Both the early and late contractions were separated when the longitudinal AC between 200-1000c/sec was applied.At the frequency higher than 500c/sec the early contraction became a twitch.In the strong transverse AC field the late contraction was dominant and it was decreased at more than 2000c/sec.
3. In the excess potassium (9-18mM) solution the early contraction was abolished.
4. Both contractions were decreased by the sodium removal or the presence of 10-8g/ml tetrodotoxin.
5. The effect of SP stimulation was similar to that of AC and the difference in the frequency characteristics was explained by the difference of electrical changes.
6. In the sodium-free solution, strong AC or SP evoked some tension, which was decreased with increasing frequency.Transverse AC was more effective than SP at less than 200c/sec but the effect was reversed at more than 200c/sec.
7. Raising the external calcium concentration, the late contraction in the excess potassium or sodium deficient solution was augmented.
8. In the chloride-free solution the late contraction was augmented and the relaxation was slowed.View full abstractDownload PDF (1377K) -
Masahiro OHTA, Nobuo TASHIRO1968 Volume 18 Issue 4 Pages 432-445
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The pyramidal tract response to cortical stimulation was examined in twenty adult rats and was compared with the antidromic cortical response and with the histological sections of the cerebral cortex made by Bodian's method.
2. The pyramidal tract response consisted generally of two positive potentials, D and I waves.The D wave is caused by the direct excitation of the cortical pyramidal tract neurons and the I wave by the indirect or synaptic excitation of the same neurons.Sometimes there are a few I waves and sometimes there is no I wave.
3. The D wave has lower threshold for cortical stimulation and is less facilitated by repetitive stimuli than the I waves.
4. The cortical representation of the pyramidal tract response corresponds fairly well with the cortical motor area but is slightly different from the distribution of the antidromic cortical response.
5. This is well explained by histological observation of the cortical pyramidal cells and the functional significance of the apical dendrites of these cells is emphasized.View full abstractDownload PDF (1251K) -
Akihiro KUROSHIMA, Norimichi KONNO, Katsuhiko DOI, Shinji ITOH1968 Volume 18 Issue 4 Pages 446-452
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSEffect of corticotropin and cortisone on the blood flow through brown adipose tissue was investigated in the rat, employing the radioactive isotope indicator method of Sapirstein.
Administrations of corticotropin in daily doses of 2 and 5 I.U.for 5 days produced a significant increase in the blood flow. Daily injections of cortisone acetate (1mg/100g, 6-7 days) caused a similar increase in the blood flow as corticotropin did.
In adrenalectomized rats corticotropin in a daily dose of 5 I.U.for 5 days failed to affect the blood flow in this tissue.The results indicate that corticotropin exerts its effect on the blood flow in brown adipose tissue through the secretion of adrenocortical hormone.
Corticotropin and cortisone did not influence the fresh weight of brown adipose tissue in normal rats under the present experimental conditions, but in adrenalectomized rats the administration of corticotropin caused a slight decrease in the weight of brown adipose tissue.View full abstractDownload PDF (693K) -
Juro IRIUCHIJIMA, Mamoru KUMADA1968 Volume 18 Issue 4 Pages 453-461
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Cardiovascular effects of stimulation of the superior laryngeal nerve were studied in the dog by observing cardiac output and blood pressure as well as, efferent discharges in the vagus nerve.
2. The blood pressure decrease on stimulation of the superior laryngeal nerve was ascribable mostly to a decrease in cardiac output due to vagal bradycardia. No decrease in peripheral resistance was observed.
3. Only a fraction of the cardiac vagal fibers, responding to sinus nerve stimulation, were reflexly excitable on stimulation of the superior laryngeal nerve.
4. It is concluded that laryngeal nerve stimulation excites the cardiac vagal center without reciprocal inhibition of the sympathetic cardiovascular center and that the group of the cardiac vagal fibers which is excitable on laryngeal nerve stimulation is not identical with that of the fibers excitable on sinus nerve stimulation, though there is some overlapping between them.View full abstractDownload PDF (932K) -
Hiroyuki NAKAO, Mitsuo YOSHIDA, Toshinari SASAKI1968 Volume 18 Issue 4 Pages 462-470
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe aim of this investigation has been to study whether electrical stimulation of the midbrain central gray could produce negative reinforcement. Sixty seven adult cats were tested. The test learning was the switch-off behavior, an escape learning.
The positive points for the test were found in an area located laterally to the Sylvian aqueduct to the middle and caudal portion and an area extending ventro-laterally from the above described area in the caudal portion of the midbrain central gray.
These areas were situated very close to an area which elicited painsuggestive screeching in the central gray. We did not use these screechingyielding sites for the test and assumed that the negative reinforcement obtained in the present study was not due to pain but to fear in the sense of a sub jective experience.Transfer experiments of the switch-off behavior proved that central gray stimulation could induce the same motivational effect as hypothalamic stimulation did.
A well-directed attack response was induced by stimulation in the central region of the middle portion of the central gray, but an attack response was rarely obtained in comparison with a flight response.View full abstractDownload PDF (766K) -
Ayako ISHIDA1968 Volume 18 Issue 4 Pages 471-480
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The release of oxytocin from the isolated pituitary glands of the rat were determined by the bio-assay, measuring the milk-ejection pressure.
2. Ca++ is required for the high release of oxytocin observed when the glands are stimulated by exposing to excess K Locke's solution.
3. The release of oxytocin is potentiated in Na-deficient media.
4. Tetrodotoxin (5×10-7g/ml) can suppress the release of oxytocin, and this suppressive effect is also seen in Na-deficient media.
5. The addition of Mg++ (8.8mM) in the media fairly well suppresses the release of oxytocin.
6. Ba++ can substitute Ca++ for the release of oxytocin.
7. The similarity between the release mechanisms of oxytocin and vasopressin and the necessity of Ca++ in the stimulus-secretion coupling were discussed.View full abstractDownload PDF (1001K) -
Teiichiro TONOUE, Kiyoshi YAMAMOTO1968 Volume 18 Issue 4 Pages 481-488
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSEffects of thyroidectomy and thyroxine supplement were studied on amino acid incorporation into secretory granules obtained from rat anterior pituitary slices incubated with alanine-14C in vitro.Thyroidectomy stimulated the incorporation of alanine into TSH-rich granules specifically, and this stimulation was suppressed by thyroxine administration.The same suppressive effect was seen when T4 was added to pituitary slices in vitro.Since T4 dose administered in vivo or in vitro was in the range of physiological level, the effect mentioned above could be considered to be of physiological significance.It was assumed that pituitary TSH synthesis is continuously carried on under the influence of circulating thyroid hormone level, and through this mechanism the feed-back relationships are maintained, at least partly, between the thyroid and the anterior pituitary.View full abstractDownload PDF (5551K) -
Hideo SAKATA, Julio MIYAMOTO1968 Volume 18 Issue 4 Pages 489-507
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSSingle unit recording and microstimulation were performed in the primary motor area of unanesthetized, unrestrained cats.
1. Neurons in the motor cortex were excited by physiological stimulation on the skin and deep tissues.Modality and receptive fields for 96 units were studied in detail.
2. When focal stimuli were applied through the microelectrode to the same region where the unit spike was recorded, localized movements elicited were found to be closely related to the receptive fields of the units recorded in the stimulus site.
3. Thresholds of movements were measured at different depths along the electrode penetrations.Each focal region concerned with a specific movement was found to have considerable extent (usually more than 0.5mm).
4. The relationship between sensory receptive fields of units and movements elicited by focal stimulation were studied in 59 focal regions.A close topographic correlation were found between the two.There was a tendency for the limb movement to avoid the contacting ob ject.
5. Penetrations in the primary motor and primary sensory areas were performed in a same animal.No movement was elicited with microstimulation of less than 100μ A in the sensory area.View full abstractDownload PDF (1992K) -
Takeshi HOSHI, Yukio KOMATSU1968 Volume 18 Issue 4 Pages 508-519
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The sugar-induced change in transmural potential was recorded in vitro from everted small intestines taken from hibernating toads and the characteristics of the potential change were studied under various external conditions.
2. Qualitatively, the sugar-evoked potential of toad intestine had characteristics quite similar to those seen in mammalian intestine, and it was intimately related to the active sugar transport.The size of the glucose-evoked potential revealed a Michaelis-Menten like relationship with external Na and glucose concentrations, the apparent Km values for glucose and Na being dependent on the Na and glucose concentrations of the medium, respectively.
3. The portion of the intestine capable of producing a large sugar-evoked potential was confined to the upper small intestine, where the affinities for glucose and Na were remarkably high in comparison with intestines of other animals.
4. The size of the glucose-evoked potential linearly increased as temperature or pH of the medium was elevated in the temperature range of 4-32°C and in the pH range of 6.6-8.2.View full abstractDownload PDF (1052K) -
Yosiko KIMOTO1968 Volume 18 Issue 4 Pages 520-535
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. To clarify the mechanism of the tone of smooth muscles the passive mechanicalproperties of the guinea pig's taenia coli were investigated, using the universal tensile testing instrument.
2. Guinea pig's taenia coli showed excess relaxation after the release of stretch in normal NaCl Krebs solution, and after that gradually recovered its usual tone. However, as excess relaxation and recovery of tone occurred more obviously in KCl Krebs solution, the participation of the membrane potential was not always necessary for maintaining tone.
3. On the other hand, since excess relaxation and the recovery of tone did not occur in glycerol-extracted muscle fibers of taenia coli, the excess relaxation and recovery of tone were not derived from the simple viscoelastic properties of the component muscle elements.
4. The excess relaxation and the recovery of tone were linearly related to the concentration of Ca++ in the solution, inhibited by metabolic inhibitors such as DNP, NaN3 and CH2ICOOH and also by lack of glucose, restored by the addition of ATP. From this, it is presumed that Ca++ plays a leading role in these phenomena and energy rich phosphates such as ATP and creatine phosphate also play important roles. In this respect, the tone of smooth muscles is a biologically active process like the contraction of skeletal muscles and both of them can be said to have very similar features.
5. It is presumed, however, that the roles of the relaxing factor were entirely different in skeletal and smooth muscles because the action of caff eine, thymol and KSCN in smooth muscles is opposite to that in skeletal muscles.View full abstractDownload PDF (1395K) -
Katsuhide NISHI1968 Volume 18 Issue 4 Pages 536-550
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Effects of several local anesthetics on the sensory terminal of Pacinian corpuscles were studied by measuring changes in the threshold when perfused with anesthetic solutions.
2. 0.03%-Procaine solution abolished impulses from corpuscles within 5min after their perfusion, while the axon supplying corpuscles lost their excitability 30min after immersion in 0.03%-procaine solution. Impulses reappeared immediately after replacement of procaine solutions by the normal one. It took a longer time for local anesthetics to cause conduction blockage in axons supplying corpuscles than that necessary for abolishing impulses from corpuscles.
3. The effect of procaine on blocking impulses from corpuscles was increased by a reduction in Ca concentrations in the perfusing solution, while an increase of Ca ions decreased the effect of procaine.
4. The effect of procaine on impulses was not modified by changing Na concentrations from 77 mM to 308 mM in the perfusing solution.
5. Blocking potencies of six local anesthetics on Pacinian corpuscles were in suscepthe order of tetracaine> lidocaine> chloroprocaine> carbocaine>cocaine> procaine.
6. It is concluded that the impulse-initiating mechanism has a different tibility to local anesthetics from the mechanism generating receptor potentials and that procaine and Ca ions act competitively in initiating impulses at the non-myelinated terminal of Pacinian corpuscles.View full abstractDownload PDF (5713K) -
Takesi HUKUHARA, Toshiaki NEYA1968 Volume 18 Issue 4 Pages 551-562
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn both rats and guinea pigs the colonic motility, especially concerned with the transport of the content through the pacemaker area as well as the pacemaker mechanism, were studied. The results obtained were summarized as follows:
1. At the turn of the ascending to the descending part of the colon there existed a pulsating ring of constriction, pacemaker area, sending contraction waves, antiperistalsis and peristalsis.
2. The content which was inspissated to become scybalum, was anally transported through the pacemaker area by antiperistalses. The underlying mechanism might be as follows: The mucosa is stretched by the scybalum to elicit the intrinsic mucosal reflex, resulting in a rise of the excitability at the part over and proximal to the scybalum which in turn reinforces the antiperistalses there to produce the shifting of the scybalum toward the anal direction.
3. Rhythmic contractions elicited in the pacemaker area both in vivo and in vitro were reduced in strength by administration of hexamethonium, whereas they were abolished by atropine or tetrodotoxin.
4. The pacemaker area contained acetylcholine in an amount larger than its adjacent areas.
5. The histological examinations revealed that the pacemaker area was a site where the networks of AUERBACH'S plexus were denser than those observed in the adjacent areas.
6. From the results described in 3, 4 and 5 it may be concluded that the pacemaker is a site where the cholinergic neurones are much more numerous than in any other areas of the colon.View full abstractDownload PDF (4698K)
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