Studies were made to know whether some of methyl-and ethyl-derivatives of NH₄⁺can replace the role of Na⁺ in the medium concerning the ACh de-polarization of the end-plate of the muscle. The sartorius muscle of frog andtoad was used and following results were obtained:
1. The size of e.p.p. in a curarized muscle decreased very much when 4/5 of the total NaCl contained in the medium was replaced by sucrose, but a full re-covery was observed when the medium was again replaced by another one whichcontained, instead of sucrose, either NH3CH3Cl, NH₃CH₂CH₃Cl, NH₃CH (CH₃) ₂Cl or NH₂ (CH₃) ₂Cl. In a non-curarized muscle, a neuromuscular block produced bya low Na medium was recovered by applying the above mentioned solution.
2. A marked ACh contracture was demonstrated in a muscle soaked formany hours in a medium whose Na⁺ was wholely replaced by either NH₃CH₃+or NH₃CH₂CH₃⁺.
3. ACh depolarization, measured by the moving fluid surface electrodemethod, was larger in a muscle soaked in NH₃CH_3- or NH₃CH₂CH₃ Ringer thanin a normal Ringer.

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1. Effects of tetrodotoxin on the neuromuscular junction have been studiedon the nerve sartorius preparation of frog.
2. Tetrodotoxin has a potent narcotic action on nerve and muscle, withoutdepolarizing them. But, it does not suppress the sensitivity of the end-plateto ACh even at much higher concentration than needed for the narcosis ofnerve and muscle. This point is rather different from many local anesthetics.
3. When a dilute solution of tetrodotoxin was applied, the size of curarinee.p.p.(recorded by an intracellular electrode) decreased gradually to about70% of the initial value, then e.p.p. was abolished abruptly due to a conductionblock in the nerve fiber. Sometimes a stepwise change in the size of e.p.p.was observed, which may be explained by a blockage of conduction in thenerve fiber near its terminal arborization (fig. 6).
4. In most cases, a selective neuromuscular block was produced by tetrodo-toxin, but not in some cases. A neuromuscular block seemed to be more easilyproduced in a preparation whose safety factor of transmission was low.

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The secretory tubule of the horse sweat gland consists of a single layerof columnar or cuboidal cells and a myoepithelium. The gland cells are pro-vided with a brush border at their luminal end and have a number of mito-chondria and a variable amount of melanin pigment granules, but no secretionantecedents in the form of granules in their cytoplasm. There is no evidencethat they normally form secretion by pinching off or disintegration of theirdistal cytoplasm. The myoepithelial cells are thin and flat compared with thoseof the human sweat glands.
The gland cells do not contain glycogen, whereas the myoepithelial cellscontain some of it. A small amount of ribonucleic acid and only traces ofionic iron are detected in the cytoplasm of the former. Alkaline phosphatasesare demonstra ted in the brush border, the narrow zone of cytoplasm beneathit and the nucleus of the gland cells and in the myoepithelium.

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The effects of γ-aminobutyric acid (GAB) on the cortical activity wereinvestigated in the cat anaesthetized with Nembutal by applying the substancetopically on the cortical surface in a high concentration.
1. GAB suppressed both surface negative and positive components of sensoryevoked potentials, dendritic potentials and spontaneous spindle bursts. Cor-responding with the decrease in amplitude of the surface positive componentsof the evoked potentials, a recording with a microelectrode disclosed that thenegative response at the depths of the cortex was suppressed.
2. The muscular movements induced by electrical stimulation of the motorcortex suffered no remarkable change even when cortical electrical activities were completely suppressed by GAB applied to the site of electrostimulation.
3. The muscular responses induced by topical administration of strychnineto the motor cortex were abolished by GAB when negative components of thestrychnine spikes were suppressed.

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With the application of continuous excessive swimming to albino rats, the symptoms of seizure similar to the audiogenic seizure and conditioned seizure are resulted and this is called “Training seizure”.
The seizure consists of hypo-and hyperkinetic states. Judging from various symptoms, a wide area of the cerebral cortex, brain stem, cerebellum and spinal cord seem to be affected. The weight of cerebrum and diencephalon does not change so much, while the weight of cerebellum and medulla oblongata falls.
In regard to K and Na in the brain, K increases in cerebellum and medulla oblongata and Na increases in cerebllum so that the ratio K/Na is low in cerebellum.
The histological changes of ganglionic cells are extreme in cerebral cortex, while the cells of cerebellum are stable against hard training.

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1) The third effect of polarizing electrodes on the excitability of nerve can best be observed by means of the interruption method, but not by the superposition method because of the distortion due to the polarization potentials. Moreover, the nerve excitability shows momentarily on opening the polarizing current changes in direction contrary to that of electrotonus. These effects are attributed to the counter current of depolarization. Since the third effect and the counter current effect appear as the excitability changes in the same direction, the former as observed by the interruption method could in nature be taken for the latter. The present series of experiments were designed to elucidate the interrelation of the two effects concerning the duration of their actions. The height of action potentials induced by a submaximal stimulus applied to the affected region of a nerve was used in pursuing the excitability changes.
2) Immediately after opening the polarizing current the anodal polarization causes an increase, while the cathodal polarization a decrease in the excitability of nerve. These changes attain a maximum at intervals of 1-2msec. after opening and decay very slowly thereafter.
3) These changes consist of two components with different time courses. The first component decays rapidly with a time constant of several msec., while the other wanes so slowly that at the interval of 240msec. the effect is still considerable. The former must be attributed to the counter current effect, while the latter to the third effect.
4) The excitability changes due to the third effect of a prolonged polarization was observed by the interruption method with an interval of 250msec. between the interruption and stimulation. The curves thus obtained represent, even in far more regular forms, the same changes found by Suzuki et al. as the third effect by the interruption in threshold measurements.

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An experiment on the effect of the thyroid hormones and some of their metabolites upon succinic dehydrogenase activity was carried out by an improved Thunberg technique with the following results.
L-Thyroxine (T₄), L-3, 5, 3'-triiodothyronine (T₃), tetraiodothyroacetic acid (TA₄), triiodothyroacetic acid (TA₃), tetraiodothyropropionic acid (TP₄) and triiodothyropropionic acid (TP₃) depressed succinic dehydrogenase of mouse heart homogenate markedly at high concentration level. At the concentration of 10^-4 M, percent inhibition was as follows:
T₄, 23%; T₃, 14%; TA₄, 52%; TA₃, 31%; TP₄, 24%(at 5×10^-5M), TP₃, 17%.
All of the hormonal substances were effective in an activating way at their low concentrations, though the effect was rather slight and statistically non-significant in some cases. Percent activation was as follows:
T₄, 8%(10^-7M); _T3, 2%(10^-8M); TA₄, 3%(10^-8M), TA₃, 1%(10^-6M) and 3%(10^-7, 10^-8, 10^-9M), TP₄, 1%(10^-5, 10^-6M), TP₃, 2%(10^-7M) and 6%(10^-8M).
Thyronine was ineffective at all concentrations tested both in inhibition and in activation.

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The study was made of the effect of various concentration of ATP on the solubility of actomyosin in the low concentration of KCl at pH 7, in order to confirm the possiblility that ATP may also produce the “phenomenon of dual precipitation” which has been observed with Na-pyrophosphate and to clarify the relation of the phenomenon to the superprecipitation.
The results obtained are as follows:
(1) In the lower concentration of KCl at pH the solubility of actomyosin fails to run parallel with the increase of ATP concentration, but it shows dual decrease in the interim (the “phenomenon of dual precipitation” produced by ATP); one decrease appears at 10^-6M of ATP, the other in the range of the concentration from 10^-5M to 5×10^-3M.
(2) The precipitate at higher concentration of ATP occurs after going through a state of high solubility (clear phase) and is accompanied with syneresis (superprecipitation), while the precipitate at lower concentration of ATP is formed immediately after the set-out of the reaction and is not accompanied with syneresis.
(3) In this case it is noted that the condition under which the precipitate at higher ATP concentration appears is in agreement with that under which ATPase activity is highest.
(4) The mechanism of the “phenomenon of dual precipitation” produced by ATP has been discussed in detail. From this discussion, the occurrence and the grade of the syneresis is closely related not only to activity of ATPase but also to the extent of the discharge of actomyosin molecule which is considered to take place owing to its combination with ADP and inorganic phosphate (or one of these) which are produced from ATP by the action of actomyosin-ATPase.

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In 70 rabbits, the antagonistic effects of GABA on EEG against anesthetics, chlorpromazine, sodium cyanide and asphyxia were investigated.
1. The primary effect of GABA on the EEG under phenobarbital-or urethane-anesthesia was desynchronization of high voltage slow waves. Spindle bursts were less affected by GABA. The generation of regular waves of about 5 cps. in the thalamus was another characteristic of its action. These waves were sometimes observed evidently in the cortex.
2. The high voltage slow discharge induced by relatively large dose of chlorpromazine was inhibited by GABA.
3. The high voltage slow waves generating in the cortex under cyanpoisoning were likewise desynchronized following the administration of GABA.
4. EEG-activation was observed for some minutes by an intravenous injection of a few mg. per kg. of GABA. Long lasting EEG-activation by GABA could be produced by an intravenous injection of large amount or by intravenous drip infusion.
5. GABA caused also inhibition on slow waves which generated under asphyxia.
6. Other ω-aminoacids or glutamate did not show such anti-comatose effect.
7. The EEG-activating effect of GABA became rather prominent by intracisternal injection.
8. GABA facilitated EEG-arousal by afferent stimulations under deep anesthesia.
9. The EEG-activating effect of GABA under anesthesia was observable after transection at the higher medulla, but disappeared after transection rostral to the pons.
10. Topical application of GABA on the cortex did not desynchronize slow waves.

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Responses of the inverted carp's retina to focal illumination were recorded by means of a KCl-filled microelectrode about 1μ in tip diameter.
1. Positive potentials were obtained from the illuminated part, and from the surrounding area potentials of similar shape, but of opposite polarity were obtained.
2. One per cent solution of cocaine applied to the illuminated part abolished both kinds of potential. When the same solution was applied to a restricted area in the surrounding field, the negative potential recorded there increased in amplitude. This effect was attributed to suppression of a positive component caused by stray light.
3. The spectral response curves of positive and negative potentials were obtained using monochromatic lights produced by interference filters (Lange and Co.). The monochromatic lights were made equal with respect to their energy. The spectral distributions of both potentials were almost identical, showing dominant peaks at 480 and 520m E and less conspicuous ones at 580 and 620mμ. The peaks at longer wave-lengths became predominant over those at shorter wave-lengths under strong light adaptation.
4. The time-courses of positive and negative potentials were compared by the method of Lissajous' figure, and it was found that the development and subsidence of the negative potential were somewhat delayed.
5. Negative potentials were recorded at various distances from the margin of the illuminated part and their latencies were determined. Conduction velocities thus obtained ranged from 67 to 160mm. a sec., averaging 112mm.a sec.
6. The physiological mechanism of this phenomenon was discussed in comparison with similar phenomena in the cerebral cortex on one hand, with spreading induction in the human retina on the other.

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The effect of temperature on actomyosin-ATPase activity and superprecipitation was investigated in detail.
1) Actomyosin-ATPase activity increased in an approximately straight line up to 40°C, and dropped somewhat at 50°C.
2) Superprecipitation occurred from 0°C to 40°C, appearing strongest at 15-20°C. The grades in the final state of superprecipitation differ with varied temperatures.
3) Superprecipitation was inhibited from 20°C to 40°C, with the rise of temperature, in spite of increase of ATPase activity; in other words, there was a discrepancy between superprecipitation and ATPase activity with regards to temperature.
4) The above mentioned results are in approximate accordance with Yutasaka (5) and Nagai et al.(6).
5) Using the grade of superprecipitation and that of ATPase activity as the basis of the determination, experiments on the heat denaturation of actomyosin were performed. The reversibility of actomyosin with temperature was found under both conditions of the heat treatment for 15minutes at 40°C and for 1-3minutes at 50°C.
Based on these results, the mechanism of the above mentioned discrepancy between superprecipitation and ATPase activity with respect to temperature was discussed.

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The afferent impulses from the nerve trunk or a single nerve fiber to the kidney and testis of toad due to mechanical stimuli have been studied by means of oscilloscopic recording.
1) Kidney and testis are innervated segmentally with sympathetic trunks from cranial to caudal.
2) The receptive field of a single afferent fiber of these nerves is far smaller (5×5mm.²) than that of splanchnic nerve fibers (10×10mm.²).
3) The adaptation of these receptors is relatively, at times, extremely slow. The former probably belongs to the type (b) in Catton's classification or to category of type ‘A’ endings of Fessard and Segers, and the latter seems to belong to the type (d) in Catton's classification or to category of ‘pain’endings of Fessard and Segers.

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Discharges of a single neuron in response to tone bursts or continuous pure tones were studied in the secondary cortical auditory area of the cats under very light general anesthesia by means of hyperfine microelectrode technique. Difference of responses of a single neuron to sound stimulation was found between the primary and the secondary areas.
(1) Small evoked potentials by tone burst stimulation were recorded from the regions adjacent to the primary area while in the remaining regions they were hardly found.
(2) The thresholds of all neurons examined for any stimulating sounds were much higher in the secondary area than in the primary area.
(3) The latencies of responses to tone bursts were generally much longer, though variable, in the secondary area than in the primary area.
(4) Most neurons in the secondary area responded only to strong continuous pure tones and not to tone bursts alone. Their responsive frequency ranges were very wide. Sometimes, the prolonged after-discharges were observed.
(5) Neurons were also encountered responding to tone burst alone. Their responses had the same feature as those of the primary area.
(6) Measurements were done on the response areas of neurons. Some of them showed a characteristic properties similar to those in the primary area, while the others were different, the areas being wider and not having the distinct characteristic frequency.
(7) By two sound stimulation facilitatory and suppressive interactions were observed on the single neuronal responses just as in the case of the primary area.
(8) Tonotopic localisation was not clearly found in this area, because many neurons explored had no distinct characteristic frequencies. Even on the neurons having a narrow response area the situation was very complicated. In contrast to the primary area neurons were easy to be recorded from the lower half of the posterior ectosylvian gyrus.
(9) From the results described above it may be concluded that neurons of the secondary area do not play an important role for the analysis of sound, i.e for the discrimination of pitch and intensity of sound, but rather have integrative functions for analyzed component sounds.

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