1. The response pattern of binaural interaction of single auditory neurons in the trapezoid, accessory and S-segment nuclei of the superior olivary complex of the cat was described. Neurons in these nuclei were classified as monaurally responding units and binaurally responding units. The former were further classified into ipsiexcited (type I) and contraexcited (type II) “timeintensitytrading” neurons.
2. Trading characteristics to interaural time and intensitydifferences were the same in both type I and type II neurons. An extremely short time course of inhibition was found.
3. On binaurally responding units the response areas were determined separately by monaural stimulation of the two ears. The response areas were similar, with almost the same characteristicfrequency but adifferent threshold. Comparing the latency to click stimuli of the two ears, a surprising coincidence in latency of responses was found by means of computer analysis. Binaural interaction was produced in these units with long-lasting inhibition. Interneuron action with burst discharges may participate in the mechanism of this interaction.
4. Directional sensitivity of auditory neurons tofrequency modulated sound was observed at this level. Since no directionally sensitive neurons could be found at a more peripheral level, the superior olivary nuclei is the lowest level in the auditory pathway where such neurons exist.
5. “Time-intensitytrading” neurons may play an important role in the localization judgment. However, the binaurally responding units which produced a sustained inhibitory interaction between both ears must have some other function besides the localization judgment.

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Absorption of dl-methionine from the rat intestine was studied during different stages of reproduction. Radiomethionine was introduced into the intestinal lumen of anaesthetized animals and, after a thirty minute period when the fluid remained in the intestine, was collected and its activity was detected. Blood samples were taken from the portal vein at 10th, 20th and 30th minutes. Samples were prepared from the liver and the mammary gland parenchyma as well, and their radioactivity was similarly determined. Methionine and cystine content in liver and mammary gland parenchyma tissue was examined by paper-chromatography.
The results indicate that there is an increased absorption of the labelled methionine from the small intestine in the second and third week of lactation. At the 21st day post partum, the rate of absorption have returned to almost the normal values of the controls. The increase in utilization of methionine goes parallel with the increase of “tissue demands” for this amino acid. Thus the requirement of the mammary gland parenchyma for methionine be comes more evident in the second and third week post partum than is observed during pregnancy or early in lactation. The accelerated turnover of radiomethionine is supported by the rapid conversion of methionine into cystine in liver as well as mammary gland parenchyma.
No significant incorporation of radiosulphur was noted in the liver, however, the biological half life time of methionine in the portal blood proved to be considerable less than that of the control cases. The results may relate to the functional adaptation of the lactating organism to meet the higher demands for methionine supply under the conditions of the increased food intake.

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It was shown that adrenalectomized dogs maintained with DCA easily succumb to shock in mild hypercalcemia due to an idiosyncratic hepatic engorgement similar to that observed in anaphylaxis. The induction of histamine release from the liver mast cells in the absence of glucocorticoid by calcium ions has been shown to be the cause.

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1. Changes in pH of rhodopsin solution was induced following illumination with the least color changes.
2. Changes in pH of rhodopsin solution on exposure to a dim green light might be clarified into 3 components, D₁, D₂ and R.
3. Isoionic point (P₀) might be affected with temperature. At lower temperatures (6°C, 19°C) P₀ was found in a neutral range, but the higher the temperature (19°C-30°C) the smaller the Po. Relations between temperature (t°C) and P₀ may be expressed as (41-t)(7-P₀) =28.
4. At 19°C to 30°C, element R was observed on the alkaline side of P₀-curve.
5. Element R might be the summation of immediate changes in pH evoked by successive illumination.
6. Origin of element R might be a photo-release of oxygen from rhodopsin solution following illumination.

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1. An investigation has been made to make clear the site of the excitation of the tooth tissues and the sensory and transmissive mechanisms of these tissues by thermal stimulations deduced from the action potentials evoked in the odontoblast cell area and the pulpal branch of the alveolar nerve.
2. The tooth responds to thermal stimuli when cooling or heating were applied on the amelodentinal junction and the pulp of the dog's canine. The least effect is found in the case of stimulation on the dentine. The temperature causing excitation, generally, ranges from 0°C to 20°C in the case of cooling and from 30° to 40°C in the case of heating. These values are essentially similar to those obtained in the skin and other organs sensible to thermal stimuli.
3. When cooling the amelodentinal junction, two contradictory biphasic action potentials are obtained from a micropipette electrode, large in diameter, inserted into the odontoblast cell areas, whereas a single biphasic action potential is obtained by a small micropipette electrode.
4. These action potentials evoked diminish by the use of narcotic agents, or destruction of pulp tissues.
5. Based on this available evidence, a discussion by the authors follows on the synaptic contact between the odontoblast cell and the nerve fibre in the tooth pulp and on the cause of the differences of the threshold values of temperature of thermal stimulations between the data of authors and the others.

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1. The change of polarity in the ERG observed when recording was made from illuminated area as opposed to ad jacent non-illuminated regions (MoToKAWA et al., 1959) was analyzed in the isolated inverted carp retina.
2. It was shown that, in the carp retina, the conventional PIII consists of at least two subcomponents ; the distal Pill which arises in the receptor cell layer and the proximal Pill emerging from a more proximal layer. These results are similar to those observed in the retinas of frogs and turtles (MURAKAMI and KANEKO, 1966). Isolation of the distal Pill by means of a coaxial microelectrode showed that the distal Pill was not involved in polarity reversal phenomenon.
3. Utilizing the chemical agents, ammonia vapor and ethyl alcohol, which influence the ERG components in specific manner, it was demonstrated that polarity reversal could be accounted for by different distributions of the proximal Pill and the PII component. The proximal Pill was produced within the illuminated area, while the PII component had a wider spatial distribution, not being restricted to the illuminated area. The algebraic summation of these components resulted in the apparent polarity reversal.

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In depth recording studies, the ERG components have usually been localized on the basis of points of maximal amplitude or polarity reversal. However, these criteria are contingent upon definite forms of potential distribution of the ERG. According to an analysis by HASHIMOTO et al.(1961), an alternative criterion based on the point of maximal potential gradient is not so restricted in application.
Localization of the ERG components in the carp retina on the basis of the latter criterion revealed that the distal PIII originates in the receptor cell layer whereas both the PII and proximal PIII are generated in the bipolar cell layer. These findings are very similar to data obtained on the frog and turtle eye.

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In the normal female rat the peak in sexual receptivity occurs during the proestrus-estrus stage of the estrus cycle. In the androgen sterilized female rat (10μg Testosterone propionate (TP) at 5 days of age) copulation did not induce ovulation. Progesterone (2.0 mg) enhanced mating behavior in these rats with no ovulation, but the additional administration of TP 0.2 mg suppressed the ability of progesterone to increase mating behavior. In normal ovariectomized rats which otherwise do not copulate, mating behavior was induced by daily treatment of 0.2 mg TP and three injections of 2.0 mg progesterone. However, if the amount of TP was increased to 2.0 mg this action of progesterone was suppressed.
Environmental stresses such as light, sound, or odor caused persistent and prolonged vaginal cornification or prolonged diestrus. The degree of sexual receptivity was reduced; however, copulation did induce ovulation.
A possible inference is that small amounts of TP suppress the ovulating center of the hypothalamus, apparently without inhibiting the mating center in the female rat. The mating center is responsive to progesterone, which enhances mating behavior. On the other hand, large amounts of TP appear to inhibit both the ovulating and mating centers, thus rendering the mating center less responsive to progesterone.
The mating and ovulating centers are not always synchronized. Provocation of the mating center enhances activity of the ovulating center which has been rendered refractory by stressful conditions.

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In order to elucidate the role played by the limbic structure for the regulation of pituitary-ovarian functioning, electrical stimulation was applied to the limbic structure and the hypothalamus through chronically implanted electrodes, and its influence on biosynthesis of various ovarian steroids was studied in the mature New Zealand white rabbit.
The implanted rabbits were primed with estradiol benzoate in oil (0.1 mg s. c.) for 2 days prior to stimulation to ensure anestrous state. Electrical stimulation, consisting of monophasic square wave pulses, was delivered unilaterally for 30min., 60 sec. on and 60 sec. off, 190-210μA, at 0.1 msec. duration, 60 cps. The experimental results as follows.
1. Ovulation was induced in 23 out of 27 cases by stimulating the alveus of the hippocampus. Facilitation of biosynthesis of various progestin fractions accompanied ovulation. Stimulation delivered to the cornus ammonis and the fascia dentata failed to induce ovulation in all of 17 cases. In these cases biosynthesis of progestin fractions was facilitated. Estrogen biosynthesis was little affected by brain stimulation regardless of whether ovulation was induced or not.
2. Ovulation was induced by stimulating the intermediate and medial nuclei of the amygdala in all of 13 cases. Progestin biosynthesis was markedlyf acilitated in these cases. Estrogen formation was slightly increased. Stimulation applied to the medial principal and lateral nuclei was ineffective in inducing ovulation, but progestin biosynthesis was considerably facilitated. Estrogen formation was not affected.
3. Stimulation of the periventricular arcuate nucleus of the hypothalamus was accompanied by ovulation and by facilitation of progestin biosynthesis. Supraoptic stimulation induced ovulation and facilitation of progestin formation in 5 out of 9 cases. Stimulation delivered to the centralgrey was ineffective in progestin formation.
4. Ovulation was induced by LH administration or copulation. Biosynthesis of progestin was remarkably facilitated, while estrogenwas moderately increased.
5. The influence of hippocampal or amygdalar stimulationon the progestin biosynthetic pattern was quite different from that of copulation, LH administration or stimulation of the periventricular arcuate nucleus.
6. The effects of hippocampal stimulation on ovarian functions were cancelled by destroying the fornix or periventricular arcuatenucleus but not by lesioning the stria terminalis.
7. Progesterone implants in the hippocampus facilitated progestin biosynthesis in the ovary. Thus hippocampus can be regarded as a focus concerned with positive feedback regulation of progesterone release.
8. Progesterone implants in the amygdala or supraoptic region or anterior hypothalamic area were almost ineffective for the steroid biosynthetic pattern of the ovary.
9. Thus the limbic system, above all the hippocampus, plays a significant role in the brain-pituitary-ovarian system.

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1.Effects of stimulation of the central cut end of the phrenic nerve on the movements of the stomach and small intestine were investigated in dogs anesthetized with pentobarbital sodium and in the decerebrated or spinal dogs. The movements of the stomach and small intestine were recorded by means of the balloon method. The right phrenic nerve was electrically stimulated at the neck or just above the diaphragm under artificial respiration.
2. The stimulation of the phrenic nerve produced an augmentation of the gastrointestinal movements. The excitatory effects still persisted even after severing the bilateral vagus nerves, and after the severance of the bilateral thoracic splanchnic nerves, the excitatory effects were completely abolished. In one case, the severance of the bilateral thoracic splanchnic nerves did not much change the excitatory effect, but on cutting the bilateral cervical vagus nerves they were completely abolished.
3. In dogs decerebrated at the level of the midcolliculus, the excitatory effects similar to those observed in (2) were also obtained. These effects were abolished when the spinal cord was transected at the level of C3 following the severance of bilateral cervical vagi.
4. It may be concluded that the excitation of the gastrointestinal movements produced by stimulation of the phrenic nerve is elicited via the vagus as well as the thoracic spalanchnic nerves, and that one of the reflex centers is the vagus nuclei in the medulla oblongata and another is an unknown excitatory center located between the inferior colliculus and medulla oblongata.

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Sleep states and their induction by sodium butyrate were studied in acute “encéphale isolé”(transection at the spinal cord C₁ level) and “IMPM”(“isolated midbrain-pons-medulla”)(precollicular decerebration and transection at the spinal cord C₁ level) preparations. The naturally occurring ortho- and para-sleep states were observed in the “encéphale isolé” preparation. The intravenous administration of sodium butyrate (1.5-2 mM/kg) induced orthosleep state of 2- to 6-min duration, followed by a 2-12 min period of the parasleep state. Similarly, in the “IMPM” preparation para-sleep state was observed, and also was induced by the butyrate. When the same amount of the butyrate (1.5 mM/kg) was given repeatedly at about 1 hour intervals, para-sleep state was reproducible in these preparations.

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1. The dip-prism microscope has been improved to minimize movement, when the focus is adjusted.
2. With this microscope, monophasic positive spike potentials are always.recorded in the region of nerve fibers (axons) in the cat motor cortex.
3. On the other hand, in the region of the cell body, both positive-negative diphasic spikes and monophasic spikes are recorded sometimes with a slow potential component and an unstable base line.

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