It was previously very difficult to obtain cerebral evoked potentials from the human scalp because the amplitude of these responses is small compared with that of the background EEG. However, the effort to obtain this response has been successful (DAWSON 1949, 1954, COBB & DAWSON 1960). This success. has been attained by averaging the EEG response synchronously with respect to each stimulation. Currently, averaging computers, designed specifically for this purpose, have made it easy to record the response and many reports regarding the evoked potential obtained by computers have appeared (for example see BARLOW 1960 and HRBEK & MAREŠ 1964). Visually evoked potentials in man show shapes of greater variety when the eyes are open than when the eyes are closed. Generally, in the eye-closed state the response to photic stimulation is composed of an initial response and subsequent alpha-like waves. These alpha-like waves have frequencies similar to that of the background. EEG (BARLOW 1960), while in the eye-opened state the response has no such rhythmic waves. The present experiment was designed to determine further the nature of these alpha-like waves resulting from photic stimulation. Theresults suggested that these alpha-like waves may contribute to the related. phenomenon of photic driving of the EEG.

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1. The relation between the response to photic stimulation and the photic driving was investigated on 25 students of our school.
2. In the eye-closed state, simple sinusoidal waves of large amplitude were obtained by continuous rhythmic photic stimulation of a frequency equivalent to that of the alpha-like waves resulting from photic stimulation.
3. Averaged waves of the EEG responses to the stimulation with frequencies lower than that of the alpha-like waves were composed of a few small characteristic waves. These small waves may be composed of the initial response and the rudiment of the alpha-like waves.
4. With frequencies above that of the alpha-like waves the initial response only was observed in the averaged waves.
5. In the eye-opened state an increase of the response amplitude to each photic stimulus in the train of stimulation at about 10 cps was not observed, while in the eye-closed state the response to each stimulus in a train of the same frequency stimulation augmented up to the 7th stimulus from the beginning of the train.
6. In drowsy state photic driving of theta waves was not observed even at a frequency of stimulation within the theta wave range.
7. Photic driving of alpha waves appears to be due to the summation of alpha-like waves resulting from each photic stimulus in the train of stimuli.

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By using the New Zealand White rabbits with chronically implanted bipolar electrodes in the several parts of the brain, studies of the influences of electrical stimulation of the limbic system and the hypothalamus upon progesterone and estrogen formation in the ovary and ovarian progesterone output were carried out. Effects were studied through observations upon inducement of ovulation and upon incorporation of radioactivity into progesterone and estrogen (estradiold-estrone) by the ovarian homogenates in vitro with (1-¹⁴C) acetate.
The implanted rabbits were primed with estradiol benzoate in oil (0.1mg s. c.) for 2 days prior to stimulation to ensure an estrous state. Electrical stimulation, consisting of monophasic square wave pulses, was delivered unilaterally for 30 min., 60 sec. on and 60 sec. off, 260-280μA, at 0.1 msec. duration, 60 cps. The results were as follows:
1. Ovulation was induced by 260-280μA electrical stimulation of the hippocampus in the estrogen primed rabbits in the 20 out of 30 cases. Almost no, differences were observed between the effect of electrical stimulation of the dorsal and the ventral parts of the hippocampus. Similar results were observed. in the effects of stimulation upon the intermediate nucleus of the amygdala and the periventricular arcuate nucleus. The ovulation induced thereby was. blocked by bilateral lesions of the dorsal or the ventral fornix, by a massive lesion of the septum, or by a localized lesion of the periventricular arcuate nucleus including the adjacent regions. On the contrary, when the stria terminalis was damaged bilaterally, hippocampal stimulation still produced hemorrhagic follicles in the ovaries.
2. Electrical stimulation of the hippocampus enhanced progesterone formation in the ovary more than that of the amygdala and the periventricular arcuate nucleus. But, it showed an unappreciable difference in estrogen formation. among these three regions. The ratio of (¹⁴C)-incorporated estrogen to (¹⁴C)-incorporated progesterone (E/P) showed a lower value in the hippocampus than in the other areas.
In respect to progesterone labelling from (1-¹⁴C) acetate by the ovarian homogenates, the ovarian progesterone output and the E/P ratio, little difference was observed between the effect of electrical stimulation of the amygdala. and the periventricular arcuate nucleus of the hypothalamus including the posterior tuberal region. When the dorsal or the ventral fornix was damaged bilaterally, the synthesis of ovarian progesterone and estrogen and the ovarian progesterone output were lower than those of the control without regard to hippocampal stimulation. But in the animals with lesion in bilateral stria terminalis hippocampal stimulation retained the facilitatory effect upon the formation of progesterone and estrogen and the progesterone output. These findings may suggest that the effect of hippocampal stimulation upon the ovary was exerted through the fornix and the basal hypothalamus including the arcuate nucleus, and not through the stria terminalis.

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Methods employing various types of capsules for the measurement of sweat volume and for the collection of sample sweat were studied; the filter paper method was found to be the most reliable and easiest to use among the methods examined. Using the filter paper method, sweat volume as well as sweat chloride content from a small skin area were measured during the sweating response to a high environment temperature. The following results obtained:
(1) Individually reproducible response patterns were observed both for sweat volume and sweat chloride content, suggesting a classification of the patterns into four types. Type I: Large sweat volume with high chloride content. Type II: Large sweat volume with low chloride content. Type III: Small sweat volume with high chloride content. Type IV: Small sweat volume with low chloride content.
(2) Determinations on various parts of body revealed that regional variations exist in sweat chloride content. In general, sweat chloride content declines according to the following order: head and neck, middle line on the chest, pectoral region on the chest, forearm (flexor and extensor side) and back of hand; this sequence is the same for most subjects.
(3) Year around experiments have demonstrated clear seasonal fluctuations in sweat chloride content. In all 12 subjects (5 males, 3 females and 4 children), sweat chloride was much higher in winter than in summer. It generally began to rise in early September, (in some subjects during end August) toward high winter levels, and fell toward low summer levels from May on. Sweat chloride content were much higher in all adult males, especially in the winter, than in females and children. This resulted in wider seasonal fluctuations in sweat chloride in men than in women and children.
(4) These seasonal fluctuations in sweat chloride content were observed to follow the same pattern in the various regions of the body.
(5) The parallel relation between sweat rate and sweat chloride content was exhibited less markedly in subjects who secrete sweat of dilute concentration, and vice versa. This relationship could also be applied to seasonal changes in sweat chloride excretion.
(6) It was demonstrated that the sweat chloride level is correlated negatively to the degree of vascular responsiveness as measured by a vascular reaction test to cold.
The findings obtained are thought to support strongly the idea that the chloride excretion in sweat is controlled mainly by the systemic effect of climatic conditions through its influence upon salt reabsorption activity of the gland. It was also suggested that the ability of sweat glands to excrete chloride may be closely related to the other thermoregulatory functions.

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In the previous papers two antagonistic areas in the pons concerning micturition, the pontine detrusor nucleus (PDN) and the pontine urine-storage nucleus (PUSN), were reported. In the present paper the interference between these two pontine areas was investigated by means of electromyogram of the external urethral sphincter. The conclusions are as follows:
1. PDN stimulation elicits strong vesical contraction with simultaneous disappearance of discharge from the external urethral sphincter.
2. In the resting bladder, stimulation of PUSN results in an increase of discharge from the external urethral sphincter despite the absence of recognizable change in the intravesical pressure.
3. If during the long-lasting PDN stimulation PUSN is stimulated for a while, sphincter discharge reappears with the inhibition of the rise of the intravesical pressure corresponding to the period of PUSN stimulation. This phenomenon can be observed also in bladderless preparations.
4. The significance of this interference for micturition and urine-storage was discussed in detail.

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1. In the isolated preparation of guinea-pig's taenia coli the tension and the spike discharge have been recorded simultaneously.
2. When the muscle was stretched, the frequency of spike discharge increased with the increase in tension developed by stretch, but the maximum frequency of spike discharge during the spontaneous contraction did not alter, and even decreased at the extremely stretched muscle.
3. The magnitude of spontaneous contraction decreased by synchronization of spike discharges.
4. On application of electrical stimulus the evoked contraction was followed by the quick and deep relaxation. At least a part of this deep relaxation is neither the result of cessation of spike discharge nor the result of adrenaline release. Strong contraction inhibited further contraction probably by lowering the inner visco-elasticity of muscle cell.

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1. On paralyzed dogs the electrical activity of the left sympathetic and parasympathetic cardiac nerves was recorded simultaneously with the activity of the cerebral cortex (sigmoid gyri).
2. The electrical activity of the sympathetic postganglionic fibers (superior cervical and “stellate” ganglia) increased when the anterior or posterior sigmoid gyri were activated. When a self-sustained activity was evoked in these areas the increase in sympathetic activity lasted as long as the cerebral self-sustained episode (FIGS. 1 and 2). The magnitude of the increase in the sympathetic discharge was in general parallel to the increase in the activity of the anterior sigmoid gyrus (FIGS. 6 and 7).
3. The self-sustained cortical response, evoked by the stimulation of convolutions other than the sigmoid, did not produce by itself changes in either the activity of sympathetic cardiac nerves, the systemic blood pressure, the heart rate or in the pupillary size (FIGS. 8B). Such modifications appeared only when the self-sustained activity spread from the stimulated area to the sigmoid gyri (FIG. 8C).
4. The pattern of the sympathetic activity of the cardiac nerves showed two types of responses (tonic and clonic) which coincided with the tonicclonic stages recorded from the anterior sigmoid gyrus (FIGS. 3 and 5). The self-sustained activity ended suddenly and at this moment the sympathetic discharge diminished or even was abolished (FIGS. 1, 2, 3, 5 and 9). This reduction in the sympathetic discharge appeared simultaneously with the cessation of self-sustained activity and lasted 2 to 13 seconds.
5. The above mentioned effects were observed after bilateral vagotomy and also when the changes in systemic blood pressure, produced by the cortical self-sustained activity, were minimized by means of a compensator system.
6. The self-sustained cortical activity of the sigmoid gyri produced during the initial part an increase in the vagal discharge (FIGs. 4 and 5) which was in general followed by a gradual reduction ; at the final part of the self-sustained episode the reduction was so evident that the vagal discharges were abolished.
7. Simultaneously with the abrupt cessation of the self-sustained activity and during the sympathetic inhibition an increase of the vagal activity was observed (FIGS. 4, 9 and 10). The cardiovascular changes observed during the self-sustained cortical activity are discussed considering the relationships between the magnitude and temporal course of sympathetic and parasympathetic efferent discharge.

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Some characteristics of the electrical activities of the pontine reticular formation (PRF), recorded with gross- and micro-electrodes following stimulation of either the sciatic or the superficial radial nerve, were studied under the effects of stimulation of the mesencephalic reticular formation (MRF). The experimental animals were exclusively unanesthetized cats, immobilized with succinylcholine chloride or Faxédil.
1. The peripherally evoked PRF potentials were composed of the initial positivity and the following negativity, this potential form being independent of the site of stimulation. The latency and the duration of the initial positive component were 10-20 msec and 10-30 msec, respectively, while the negative component had a duration of 40-75 msec. The MRF-induced, PRF potential was triphasic having the initial positivity. The threshold intensity of stimulus for eliciting the PRF potential was dependent on stimulating sites of the MRF.
2. The peripherally evoked PRF unit response was classified into two types. The first type unit response occurred with an initial burst of spikes without being followed by after-discharges, whereas in the second type an initialburst of spikes continued to regular discharges with gradually decreasing frequencies. The mode of activation of the PRF unit was not essentially different between the MRF and the peripheral nerves. For a given stimulating point of the MRF, two types of the PRF unit were distinguished according to the threshold of activation (low-threshold and high-threshold). The discharge pattern of a given PRF unit to MRF stimulation was not fixed but variable depending on the site of stimulation.
3. There are two types of spontaneous discharges in the PRF, the one with an irregular pattern of less than 10c/s and the other with a relatively regular pattern at 30-60 c/s. The firing rates of the PRF unit were mostly increased by MRF arousal stimulation.
4. A single shock applied to the MRF with strengths sufficient for eliciting the PRF potential suppressed the peripherally induced, PRF potential for 10-40 msec.
5. The peripherally induced, PRF potentials were suppressed during and after repetitive stimulation of the MRF, this being parallel to EEG arousal.
6. Repetitive stimulation of the MRF increased the peripherally evoked, PRF unit response. The facilitatory effect was found more frequently in the high-threshold units than in the low-threshold ones, whereas this relation was reversed with the inhibition.
7. It was suggested that the descending connection from the MRF is not diffuse, but rather specific.

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Cardiac irregularity found in oyster was studied in relation to interaction between cells or groups of fibers, by means of action potential recording from the muscle fiber of each of the connected half-ventricles.
1. A periodical appearance of abnormal heart rate being mainly due to the difference in rhythm of the two half-ventricles was frequently observed.
2. The cardiac rhythm becomes somewhat irregular owing chiefly to change in the shape of the transmembrane action potential, particularly that in the plateau phase.
3. The heart rate is found to be disturbed very often due to the block of conduction.
4. The rhythm becomes remarkably disordered after some severe treatments.
5. The heart rate is disturbed either transiently or sporadically by a considerably slow rate of the rhythm of the other half-ventricle.
6. The interaction between the two halves of the ventricle is complicated. As the result of such interaction, the heart rhythm is frequently disordered.
7. Wenckebach phenomenon is recognized also in the oyster heart and the cause of its formation was discussed.
8. Disorders of heart rhythm are considered to be aroused not only by disorders of impulse formation and disorders of conduction, but also by disturbance of interaction between fibers.
9. In the oyster, arrhythmias involving greatly increased heart rate such as flutter and fibrillation was not to be found.

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