1. The Na and K content of the sartorius muscle of toads treated with various metabolic inhibitors was measured. In IAA the muscle gains Na and loses K, the gain of Na being nearly equal to loss of K.
2. The muscle also loses K in DNP, but it either loses K or accumulates Za, depending on the concentration, temperature and soaking time. Therefore in the muscle poisoned with DNP the Na secretory machanism operates quite independently from K uptake.
3. The oxygen uptake is increased by several folds in DNP-treated muscles compared with that in the control. At 15°C the oxygen uptake shows the maximum with a concentration of 0.025mM, while at 25°C the maximum lies at 0.05mM. The oxygen uptake is not increased in parallel with the facilitation of the Na secretion.
4. The membrane potential of the muscle fibre treated with inhibitors is reduced with time and in parallel with the decrease in K concentration inside the muscle fiber. There is a good correlation between the membrane potential and the K content of the muscle, suggesting that the former is determined primarily by the latter.

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1. The nature of neuromuscular depression, i. e., the gradual decline in size of e. p.p.'s during repetitive stimulation, was investigated in curarized nervemuscle preparations of the frog and rat.
2. The sensitivity of the end-plate to ionophoretic micro-application of ACh remains entirely unchanged even when the size of e. p.p.is greatly reduced after repetitive junctional activities.
3. When the transmitter-receptor reaction is enhanced or depressed presynap tically, the degree of neuromuscular depression is correspondingly augmented or reduced, whereas the depression is little modified when the reaction is altered postsynaptically.
4. It is concluded that the principal cause of neuromuscular depression is the gradual decrease of transmitter release per nerve volley, probably in consequence of partial exhaustion of the store of available transmitter, and that the desensitization of end-plate by ACh does not play any appreciable part in neuromuscular depression.

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This paper deals with the best conditions for preparing rhodopsin particulates by means of sonic treatment of rod outer segments separated from the dark adapted cattle retina. Thorough washing and subsequent sonic treatment of water suspension of rod outer segments gave fairly high optical purities, namely, ca. 0.3 of E_400mu/E_500mu and ca.3.0 of E_280mu/E_500mu.As long as rhodopsin articulates were kept at 7°C, the absorption spectra remained fairly stable even 7days after preparation in spite of slightly growing turbidity of solution.
Electron microscopic observation revealed that rhodopsin particulates consisted of globular particles in diameter of 50 Å to 200 Å. When illuminated, the diameter of particulate became larger, probably indicating the tendency of aggregation of particles upon illumination. On the basis of this observation, a model involving the rearrangement of rhodopsin lipo-protein micelle was postulated.
Titration of rhodopsin particulates and the bleached products signified a decreasing tendency in the number of acid titrable groups of the latter which almost reached 15% of total titrable groups at PH 3.01. This result is not consistent with the titration data of rhodopsin digitonin complex. 87 groupswere titrable per mole of rhodopsin in the range of PH 3.75 to 10.0. Also, it seems true that the isoionic point of rhodopsin particulates (6.3-6.5) is shifted remarkably to the alkaline side than that of rhodopsin digitonin complex (5.2-5.3).
This work was mainly performed at Honjo Laboratory, Department of Biology, Faculty of Science, Osaka University. The author is particularly obliged to Professor Ichijiro HONJO for his courtesy in making available the facilities of his laboratory and in preparing this manuscript.
Sincere thanks are also due to Professor Sadayoshi KAMIYA, Dapartment of Ophthalmology, Medical School of Nara, for his generous help in making this accomplishment possible.
The author is also indebted to Dr. Yuzo SEKOGUCHI of Honjo Laboratory for his valuable suggestion and kind help throughout this experiment, and to Dr. Akira TANAKA for his technical contribution in preparing the electron microscopic pictures.

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I. Arousal and sleep EEG patterns in rat. The EEG patterns in the neo-, paleo-, and archicortices with their related subcortical nuclei were almost the same as those of cats or rabbits.
FIG. 1 (A) is an example of the arousal pattern in which the amygdala shows low voltage fast waves (ca.30 cps), the hippocampus regular slow waves (4-6 cps), and the frontal cortex low voltage fast waves (ca.40 cps).
FIG. 1 (B) shows the drowsy pattern elicited by intravenous administration of progesterone (15mg/kg), in which irregular slow and fast waves are seen in the hippocampus, marked spindle bursts in the frontal cortex and high voltage synchronized waves in the amygdala. This pattern is closely resemble to the pattern shown in FIG. 2 (B) which occurred after intraperitoneal administration of 5mg/kg pentobarbital (Nembutal).
The administration of larger doses of a central depressant caused moremarked lowering of the electrical activity level of the whole brain. FIG. 1 (C) shows the sleep pattern with slow waves and spikes in all traces after intraperitoneal addition of 40mg/kg progesterone.Spontaneously occurred drowsy and sleep patterns were similar to the pattern elicited artificially by drug administration.
From these findings it may be said that the rat's EEG shows the similarpatterns as observed and classified in the cat's EEG by TOKIZANE (1958) and KAWAMURA (1959).
II. Activation pattern in lower level in rat. The activation pattern in lower level has been defined by IMAMURA and KAWAMURA (1959, 1962) to indicate the peculiar electrical activity which may be ranked between arousal and drowsy states.
In rats, the similar pattern was sometimes produced in the neocortex by reticular stimulation or frequently seen under influences of various kinds of central depressant drugs. Thus, after intraperitoneal administration of 30 mg/kg pentobarbital, reticular stimulation (100 cps, 1msec, 1.0 volt) produced the marked activation pattern in lower level in the neocortex, which was characterized by relatively regular waves (7-10 cps) of high amplitude (FIG. 3. B), and by stronger stimulation (1.5 volt) it was rather suppressed as shown in FIG. 3.(C). In this case, the hippocampal regular slow waves were superimposed with enhanced fast waves, although frequency of the slow waves markedly diminished.

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The brain stem of toads was explored with a tungsten microelectrode in order to locate the somata of respiratory neurons, with a simultaneous application of electro-myography to the submaxillar muscle.
1. Small respiratory neurons for the gorge respiration were located in a limited region underneath the striae acousticae. The region is near the margin of the floor of the fourth ventricle at the level of the root of the vestibular nerve and at the depth of about 1.2-1.5mm from the dorsal surface of the brain.
2. Their activity was characterized by continuous discharges of low spikes of about 100μV in amplitude with fluctuating intervals, by which the ventilation movement of the submaxillar muscle was put to action.
3. During the ventilation movement (gorge respiration), slow muscle responses were exclusively recorded from the submaxillar muscles. Therefore the small neurons which caused the responses were assumed to belong to the slow motor system.
4. Large neurons for pulmonary respiration were found more extensively around the region of the small neurons, reaching the optic lobe frontally and the obex caudally.
5. Large spike bursts of about 300μV in amplitude due to activities of the large neurons were always preceded by several low spike discharges of about 85/sec in frequency, which seems to be caused by an increased excitability of the small neurons. Then twitch (fast) responses occurred in the submaxillar muscles, always preceded by a short train of high frequent slow muscle responses.
6. Activities of their large neurons were measured to irradiate at about 0.2 to 0.25 rnisec along synapic relays between them.

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1. Employing the centrifugal fractionation method, the particulate 5-HT of rabbit brain was chiefly found in the heavier granules of crude mitochondrial fraction as well as in the microsomal particles. The higher 5-HT content of microvesicle fraction reported by WHITTAKER is attributable to his omitting the acetone extraction procedure, the activity observed by him being mainly that of substance P.
2. Such a particulate 5-HT was released by raising temperature, lowering pH, lowering osmotic pressure and by treating with ether, acetone or with higher concentration of KCl, while other cations such as Na⁺, Ca⁺⁺ and Mg⁺⁺ showed hardly any effect up to 200mM. Reserpine caused loss of particulate 5-HT in about 40% for 4 hours.
3. The particulate 5-HT is susceptible to monoamine oxidase, which seems to destroy it nearly completely when incubated at 37°C.
4. The 5-HT-containing granules show hardly any uptake of 5-HT added to the suspension media at 4°C.
5. In the microsomal fraction, a 5-HT-inactivating action is proved, which disappears after boiling and is inhibited by iproniazid, but not so activated with ether as reported by WHITTAKER.

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1. The effects of replacement or concentration change of a constituent ion of Ringer's solution on the twitch tension and action potential of frog sartorius muscle were investigated.
2. The Na removal within the limit of 75% improved the excitation-contraction coupling.
3. The excess K facilitated the excitation-contraction coupling under the limit of 9 mEq.
4. In the depolarized muscle, the excess Ca facilitated the coupling, but in the non-depolarized muscle, the twitch tension was depressed by the excess Ca, while the spike height increased.
5. In Ca-free Ringer's solution, none of significant change in mechanical response was observed at single or low frequency stimulation. But the maintenance tension at high frequency stimulation fell down far quickly than the control.
6. The Cl removal improved the excitation-contraction coupling.
7. TEA, substituted for Na, and anomalous anions, substituted for Cl, prolonged the duration of spike potential and increased the negative after-potential as well as the twitch tension. The relation between electrical change and mechanicalresponse, however, was not uniform. Because the specific effect of each ion was superposed on the general effect of Na and/or Cl removal.
8. The significance of Ca-entry to the excitation-contraction coupling as related to the depolarization and Na-permeability, and the dual (general and specific) effects of ion substitution were discussed.

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The effects of the immersion of nerve-muscle preparations of frog in Ringer solution on the excitation and contraction phenomena were followed up to 24 hours.
1. The twitch responses of the muscle to indirect and direct electrical stimulations decreased to quite similar degree until 8 hours after immersion. However, it was observed that the twitch responses to indirect stimulations reduced more prominently after 8 hours.
2. Until at least 8 hours after immersion, no changes in action potentials of the whole muscles elicited by indirect stimulations were observed.
3. Not only the action potentials of the nerve trunks, but also the resting and action potentials of the directly stimulated muscle fibres were quite similar to those in the control even at 24 hours after immersion.
4. There were no differences in size and shape of the caffeine-induced contractures between the muscle immersed in Ringer solution for 24 hours and the control.
5. In the muscle surviving for 24 hours in Ringer solution, the threshold concentration of Ach to produce contractures was about 10 times higher than that in the control.
6. It is concluded that the failure of the E-C coupling processes in the surviving nerve-muscle preparations starts in earlier stage prior to functional disturbances of the end-plate, and remains incomplete even after 24 hours when the end-plate transmission fails completely.

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