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Volume 21 (1971)
- Issue 6 Pages 591-
- Issue 5 Pages 465-
- Issue 4 Pages 359-
- Issue 3 Pages 241-
- Issue 2 Pages 119-
- Issue 1 Pages 1-
Volume 21, Issue 4
Displaying 1-7 of 7 articles from this issue
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Takashi YAMAMOTO, Yojiro KAWAMURA1971 Volume 21 Issue 4 Pages 359-374
Published: 1971
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSResponses of the chorda tympani and lingual nerve to cupric solution applied to the tongue were recorded in the rat, and the taste effectiveness of this solution was evaluated. The results obtained are as follows:
Integrated responses of the whole chorda tympani to cupric salts (above 10-3M) consisted of two components: an initial transient response, and a steady response each response showed different concentrationresponse magnitude curves.
Obvious nerve discharges were recorded from the chorda tympani by water rinse after previous application of strong cupric solution (above 5×10-3M) and these discharges were maintained over 30min.
Previous application of cupric solution (below 10-3M) enhanced or suppressed the responses of the taste nerve to four subsequently applied fundamental taste stimuli. Responses to sucrose and quinine-HCl solutions were strongly and, in many cases, irreversibly suppressed by 10-4 to 10-3M cupric solution, but these suppressed responses recovered to the control level after application of 0.05M EDTA to the tongue surface for 30sec.
Single fiber analysis of taste effectiveness of cupric solution revealed that the nonspecific taste fibers of the chorda tympani, which responded to the four fundamental taste stimuli, induced marked responses to cupric solution, but no response was observed in the specific acid and salt taste fibers or in some of the quinine fibers.
The mechano-and thermosensitive fibers in the lingual nerve did not respond to cupric solution applied to the tongue. The taste effectiveness of cupric salts and the concerned receptor mechanisms were discussed based on the results of the present experiments.View full abstractDownload PDF (1288K) -
Keiichi MIMURA1971 Volume 21 Issue 4 Pages 375-386
Published: 1971
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThere is a periodic fluctuation in amplitude of the alpha wave known as the “waxing and waning” phenomena. This periodicity was studied in human adults by means of the simplified method of frequency band analysis on the amplitude envelope of the alpha wave.
1. At least four types of fluctuations were found. Their periodic times ranged from 30 to 60 sec in type I, from 10 to 20 sec in type II, from 5 to 7 sec in type III and about 1 sec in type IV.
2. In each type of fluctuation, the phase was the same in all regions of the cortex.
3. Delivery of a steady light stimulation produced effects in only type I fluctuation.
4. The frequency of the alpha wave was also found to fluctuate at periodicities corresponding to type I and II amplitude fluctuations.
5. The amplitude of the flicker-evoked response also was noted to show periodic fluctuations. Four kinds of periodic time were found and they were almost the same as those in the spontaneous alpha wave.
6. The fluctuation of type IV had no correlation with the heart rate.
The possibility was discussed that these periodic fluctuations are dependent upon cortical excitability changes and that therefore the periodic phenomena in perception are based upon the neurophysiological mechanism.View full abstractDownload PDF (944K) -
Keiichi MIMURA1971 Volume 21 Issue 4 Pages 387-404
Published: 1971
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe periodic fluctuations in the amplitudes of the evoked potential produced by intermittent light stimulation of low frequencies were analyzed for a variety of areas such as the cortex, specific and nonspecific nuclei and midbrain reticular formation in the cat's brain. From the periodic time, four types of fluctuations were found, i. e., type I, 30-50 sec; type II, 7-12 sec; type III, 3-5 sec; and type IV, 0.7-1 sec. These were almost the same as the classification of the fluctuations in the alpha wave in man. The following characteristics were found in each type of fluctuation.
Type I fluctuation showed an excitability change common to the entire nonspecific system, including the cortex, regardless of the site or the component of the evoked potential.
Type II fluctuation was an excitability change of nonspecific origin and showed an antagonistic pattern between CM and the RF-cortex system.
Type III fluctuation showed an independent activity in CM and RF, and the type III activities in CM and RF separately affected the cortex.
Type IV fluctuation was a local activity in each portion of the brain and had a closer relationship within the specific system, rather than within the nonspecific one, as compared with other types.
The functions and physiological or biological significance of these periodic fluctuations of excitability were discussed through comparisons with different periodic phenomena in the central nervous system.View full abstractDownload PDF (1413K) -
Saburo HOMMA, Kenro KANDA, Shiroh WATANABE1971 Volume 21 Issue 4 Pages 405-417
Published: 1971
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Tonic activation of muscular activity was observed during forced vibration of the gastrocnemius and soleus muscles in the decerebrate cat. Such tonic activity was not observed in the tibialis anterior muscle.
2. Intervals of both unitary EMG and motoneuronal spikes were shown to occur according to the principle of integer multiplication of vibratory cyclic time.
3. Gradual recruitment of tonic vibration reflex (vibratory facilitation) was found to survive after the cessation of vibratory stimulation (postvibratory facilitation).
4. Nonsequential interspikes revealed that gradual tonic recriutment is effected by the spikes with a shorter firing interval.
5. Muscle activities during TVR may be effected by PTP with some excitatory frequency associated with that of the applied vibration.
6. Postvibratory facilitation did not correlate with the vibratory frequency. The firing of such phases may be determined by the intrinsic repetition rate of the individual motoneuron.View full abstractDownload PDF (1245K) -
Saburo HOMMA, Kenro KANDA, Shiroh WATANABE1971 Volume 21 Issue 4 Pages 419-430
Published: 1971
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Both in human subjects and monkeys, the tonic vibration reflex, TVR, was observed during vibratory stimulation of the muscle. In the latter, TVR reaches its maximum soon after vibratory application.
2. In the monkey, unitary EMG was recorded during vibratory stimulation and nonsequential interspike interval histograms were obtained. Intervals of unitary EMG were shown to occur on the principle of integer multiplication of the vibratory cyclic time.
3. A gradual increase or decrease of TVR during vibratory stimulation in the human subject or the monkey is effected by the EMG discharges of shorter or longer firing intervals which occur on this principle.
4. Both in human subjects and monkeys, the TVR becomes larger with the higher range of vibratory frequency. Beyond a certain vibratory frequency the TVR shows a gradual decrease. The relationship between the TVR and the vibratory frequency was called the TVR-f relation. There is an optimal frequency of vibratory stimulation for producing the largest TVR tension.
5. The size of the reflex tension from TVR-f relation depends on the discharge frequency of the unitary EMG, which occurs according to the principle of the integer multiplication of original vibratory cyclic time.View full abstractDownload PDF (1262K) -
Fumio ITO1971 Volume 21 Issue 4 Pages 431-441
Published: 1971
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Electrical responses of isolated leaf-like receptors in the frog sartorius muscle to muscle stretch were recorded by means of the paraffin gap method.
2. The sensory terminal is always positive by 0.25 to 1mV to the proximal portion of the axon. The magnitude of the steady potential decreases with increase in the terminal-gap distance. Crushing of the axon, especially under the paraffin pool, yields large changes of the steady potential.
3. A slow potential like a spindle potential in the muscle spindle receptor was observed during muscle stretch. The deflection was negative in some cases and positive in others, and the direction of the deflection was often changed by the movement of the axon in the paraffin pool during muscle stretch.
4. Monophasic and triphasic spikes occurred superimposed on the slow potential during muscle stretch of supra-threshold strength, when recordings of potential changes were made across the paraffin gap situated at a point along the axon less than 1mm from the isolated end of the nerve. The amplitudes of the monophasic spike and of each peak in the triphasic spike except the notch decreased exponentially with increase of the terminal-gap distance from 2 to 7mm. Consequently, it has been considered that the notch may be due to the conductive impulse while the others may be local activities originating near the sensory terminal or may consist of both the local activity and the conductive spike.
5. The slow potential and the local activities during muscle stretch were discussed in relation to a generator potential or a trigger mechanism in the mechanoreceptor.View full abstractDownload PDF (1333K) -
Sunao IMANISHI1971 Volume 21 Issue 4 Pages 443-463
Published: 1971
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The membrane potential of Purkinje fibers excised from the left ventricle of the dog heart was changed to various potential levels using the partition chamber method.
2. The existence of pacemaker activity of two kinds which are due to different mechanisms was suggested in Purkinje fibers: one is a natural pacemaker activity at high membrane potentials and the other, oscillations at membrane potential below about-60mV.
3. The natural pacemaker activity is strongly dependent on extracellular Na ions but little affected by changes in extracellular Ca ions except for an indirect action resulting from a change in the threshold potential.
4. On the other hand, the spontaneous repetitive discharges (oscillations) at low membrane potential depend markedly on extracellular Ca concentration but only slightly on Na ions.
5. It is postulated that background inward currents, responsible for generating the low voltage oscillation, are carried by both Ca and Na ions which pass through a probable “slow channel, ” which is activated at a membrane potential of about-50mV in normal Tyrode solution.View full abstractDownload PDF (2706K)
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