1. Reflex tension, electromyograph (EMG) and afferent discharges were observed during sinusoidal movement in the gastrocnemius and soleus muscles of decerebrated cat.
2. The amplitude of tension began to decrease at over 9Hz in the gastrocnemius and at over 5Hz in the soleus. The phase angle of reflex tension showed the phase lead at low frequencies and the phase lag at over 14Hz in the gastrocnemius and at over 7Hz in the soleus. The alternate cycle fluctuation of tension was observed at over 22Hz in the gastrocnemius and at over 14Hz in the soleus.
3. The phase lead of EMG was amplified with increasing frequency but began to recede at over 8Hz in the gastrocnemius and at over 4Hz in the soleus, while the amplitude of EMG increased. The alternate fluctuation of EMG was seen at the same frequency as the alternate cycle fluctuation of tension.
4. The effect of reflex tension on stretch receptors was investigated by simultaneous recording of dorsal rootlet GIa and GIb discharges, reflex tension and EMG. The GIa discharges increased with sinusoidal movement but partial acceleration and pause of the discharges were observed during a cycle. EMG group discharges were seen after the acceleration and during the GIa discharge pause. GIb discharge pause was not seen during a cycle but discharge acceleration was observed after EMG group discharges.
5. The shift in the GIb discharge possibly occurring as a result of its own reflex tension suggests that it acts as an inhibitor to successive GIa discharges and may be the cause of the alternate cycle fluctuation of the EMG at high frequencies.
6. These results were discussed by introducing the reflex system time lag due to the conduction time of the nerve and the contraction time of the muscle.

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Sweating and body temperature response were studied in a total of 268 Japanese (non-Ainu Japanese and Ainu Japanese) of various groups which differed in sex, racial and ecological status. The pattern of response for the whole period of heat application was used for the analysis of the observations. In order to arrive at determinants of body temperature response-equilibrium body temperature, rise of body temperature at the equilibrium period, and slope of changes in body temperature in the post-equilibrium period were calculated. Sweating function was represented by the determinants such as peak rate of sweating, peak Na concentration in sweat, slope of changes in the rate of sweating as well as in Na concentration in sweat in the post-equilibrium period. Latent time of sweat suppression after the maximum sweating was also measured. Sweating types were assigned to individuals according to the criteria previously reported. Correlations between determinants above mentioned were examined and discussed from point of view of heat adaptability. The results are summarized as follows:
1) Latent time and rate of sweat suppression correlates well with body temperature response in the following manner; in subjects in whom sweat suppression progressed rapidly with a short latent time, the rise of body temperature at the equilibrium period was small. In these subjects, body temperature tended to decline more markedly in the postequilibrium period.
2) It was found that the sweat rate and body temperature not always changed in the same direction in the post-equilibrium period, thus it follows that no causual relationships exist between the two in this period. Na concentration in sweat changed in most cases in parallel with the sweat rate in the post-equilibrium period. However, it was observed in not a few subjects that Na concentration increased while the sweat rate was decreasing. In these subjects, body temperature showed less tendency to decline, or conversely, a tendency to rise again even after the equilibration of body temperature was once established.
3) The analysis of the correlation between “sweating types” and determinants for body temperature response and sweating pattern revealed inter-sweating types differences in most of the determinants with a statistical significance. The equilibrium body temperature after heat application was lower in sweating types 2 and 4 than in types 1 and 3. The rise in equilibrium body temperature from the initial temperature showed a similar tendency to the above according to sweating types, i. e. smaller in types 2 and 4 than in types 1 and 3. Also, the body temperature tended to decline in the post-equilibrium period more markedly in the former types than in the latter types. Sweat suppression was produced more rapidly in type 4 than in types 1 and 3. It was suggested that there are inborn differences in sweating responses among individuals which may play some role in heat adaptability.

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To estimate the hydraulic conductivity of dog submaxillary gland, an attempt was made to determine filtration constants of the glandular epithelium by analyzing the decay curve of the stop-flow intraluminal pressure.
The time course of the decay of intraluminal pressure after cessation of the secretory stimulation was found to be expressed as an algebraic sum of two exponential functions of time, one having the rapid component and the other having the slow component:
P=Ae^-λ1t+Be^-λ2t
The rapid component is atributable to the relaxation of the myoepithelium because the rate constant of the rapid component (λ2) is in good accordance with the rate constant of the relaxation of the myoepithelium. The rate constant of the slow component (λ1) is deduced theoretically to be a product of the filtration constant and a coefficient of volume elasticity of the gland. The value of λ1, was found experimentally to be 0.00512 sec^-1, and the coefficient of volume elasticity obtained by measuring the intraluminal pressure elevated by retrograde injections of fluid was 1.52 mmHg·g-gland·μl^-1. From these results, the filtration constant of dog submaxillary gland was estimated to be 0.0033 μl·sec^-1·mmHg^-1·g-glamd^-1 on the average. Recalculating the value on the basis of the surface area of the acinus per unit gland weight, a value of the filtration constant or an approximate value of the hydraulic conductivity of the acinal surface was calculated to be 0.6×10^-11 cm³·sec^-1·dyne^-1. The numerical values of the parameters described above may be applicable under similar experimental conditions to those used in the present study.

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Perforated capsules were implanted aseptically into the brain parenchyma of dogs. The capsules became filled with fluid, and tissue accompanied by blood vessels grew within them. The internal fluid pressure of the intracerebral capsules (BC) was measured. Other perforated capsules were implanted into the subcutaneous tissue and muscle (denoted SC and MC), respectively. The fluid pressure within them was compared with that in BC. The following results were obtained:
1) The average fluid pressure in BC was+57.9±8.3 (S. E. M.) mm H₂O, and was entirely different from the-60.2±5.5 (S. E. M.) mmH₂O in SC. A significant correlation was recognized between fluid pressure and protein content in the capsular fluids of SC and MC (P‹0.01) but not of BC (P›0.05).
2) Bilateral occlusion of the external jugular veins induced a sudden increase in CSF (cerebrospinal fluid) and BC pressure. There was a return to control level on release.
3) Increase in blood pressure caused only a slight elevation of BC and CSF pressure, with clear on-off effects in the case of carotid occlusion. Stimulation of the efferent vagus led to a decrease in blood pressure and to a small decrease in BC and CSF pressure, followed by marked fluctuation when the stimulus was removed. Low pressure changes in BC and CSF, concomitant with marked changes in blood pressure, are explained on the basis of an autoregulatory mechanism affecting the brain circulation.
4) The half-time for pressure reequilibration, following injection into or removal of a small amount of fluid from the capsules, was measured. It was appreciably longer in BC than in SC.
5) The evidence for a positive pressure in BC is discussed, and it is suggested that the BC pressure may reflect to some degree both the vascular and interstitial conditions of the brain.

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Perforated capsules were implanted aseptically into the brain parenchyma of dogs. The tissue and fluid formed within these intracerebral capsules (BC) were analysed for their ions and protein content. The results were compared with those for other perforated capsules implanted simultaneously into the subcutaneous tissue and muscle, respectively (denoted SC and MC). The following results were obtained:
1) In BC and MC, the Na/K ratio was different from that of the respective control tissues (cerebral parenchyma and temporal muscle) but similar to that of both the tissue in SC and control connective tissue. The water content of the three different capsular tissues was almost identical, but in each case different from that of the respective control tissues.
2) The Na/K ratio, Cl and protein content, and electrophoretic patterns of the three capsular fluids were similar to one another, and to serum. However, all (including BC fluid) were different in composition from the CSF (cerebrospinal fluid).
3) Investigations of the effect of time lapse after capsular implantation showed that the Na and K content was generally constant over the observed period, except that the K value was high in the initial few weeks.
4) Based on the results obtained, and on our data for pressure reequilibration in BC, the nature of the fluid compartment in BC is discussed. It is considered to represent an extension of the narrow space existing physiologically between the blood capillary wall and glial membrane, and not to be part of the true interstitial fluid compartment.
5) The barrier existing between the blood and brain parenchyma may be regarded not as a single membrane but as two membranes of dissimilar nature.

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An attempt has been made to clarify the exteroceptive control mechanism of extrinsic tongue muscles in cats. For this purpose, excitatory and inhibitory receptive fields of extrinsic tongue muscle motor units on the tongue surface have been investigated in urethanechloralose anesthetized or decerebrate cats.
1. Styloglossal motor units responded with spike discharges to gentle stroking of the anterior part of the tongue dorsum. The receptive field of this reflex response has been classified into 5 types; ipsilateral filiform type (iF type), ipsilateral nonfiliform type (iNF type), bilateral nonfilifbrm ype (bNF type), ipsilateral filifbrm plus ipsilateral nonfliform type (iF+iNF type) and ipsilateral filifbrm plus bilateral nonfiliform type (iF+bNF type). The majority of styloglossal motor units were of the bNF type in urethane-chloralose anesthetized cats. On the other hand, motor units of the iF type dominated in decerebrate cats.
2. Hyoglossal motor units were divided into two groups; ventral and dorsal. Ventral hyoglossal motor units responded with spike discharges to gentle stroking of the ipsilateral posterior part of the tongue dorsum, while dorsal hyoglossal motor units to that of the ipsilateral filiform area of the anterior tongue dorsum.
3. Only a minority of genioglossal motor units responded with spike discharges to tactile stimulation of the filiform area of the anterior tongue. In most responsive genioglossal motor units, the excitatory receptive fieldwas located in the ipsi-or bilateral filiform area of the anterior tongue. In a few cats, however, the excitatory receptive field was in the ipsilateral Dosterior part of the tongue dorsum.
4. Some styloglossal and hyoglossal motor units responded with spike discharges to tactile stimulation of the ventral surface of the tongue, but none of the genioglossal motor units responded to it.
5. Some genioglossal and ventral hyoglossal motor units exhibited nonrespiratory spontaneous discharges, but no styloglossal and dorsal hyo-glossal motor units showed them. However, the majority of styloglossal motor units responded with spike discharges to jaw opening.
6. Inhibition of spike discharges was demonstrated with styloglossal and genioglossal motor units. The inhibitory receptive field of styloglossal motor unit was located on the ipsilateral posterior part of the tongue dorsum. In most genioglossal motor units, the inhibitory receptive field was on the ipsi-, contra- or bilateral posterior part of the tongue dorsum.

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Changes in the difference spectrum of the octopus rhodopsin solution with pH 10.3 were studied at about 2°C by applying the flash photolytic technique. The main peak (about 520nm) in the difference spectrum at 10 msec after a flash coincided with the peak of the calculated difference spectrum between rhodopsin and acid metarhodopsin. It was suggested that in the octopus rhodopsin cycle the acid metarhodopsin may be a precursor of the alkaline metarhodopsin even in alkaline solution.

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Effects of divalent cations on pregnant mouse myometrium and guinea pig ileum were investigated by recording electrical and mechanical activities.
1. Application of transition metal cations (Mn, Cd, Co, Ni, and Zn) inhibited the spontaneous activities of mouse myometrium. Except for Mn, treatment with these cations in a concentration of 1mM and for 1-2min caused an irreversible suppression of the mechanical response.
2. Myometrial membrane was hyperpolarized with 0.5mM Cd decreasing membrane resistance. During application, contractures induced by excess K or carbachol was inhibited. After treatment with 0.5-1mM Cd for 1-2min, electrical and mechanical activities dissociated, i. e. spike activity resumed but mechanical activity was suppressed. The membrane was depolarized by carbachol to the control value, but contraction did not developed.
3. By contrast, contracture of mouse myometrium induced by excess K or carbachol application were potentiated after treatment with Mn.
4. The effects of divalent cations on guinea pig ileum were essentially the same as with mouse myometrium, i. e. treatment with Mn potentiated mechanical response whereas other ions caused irreversible suppression.

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The effect of tetraethylammonium (TEA) on the electrical activity of mouse myometrium was investigated in combination with the use of Mn and Cd.
1. With low concentration of TEA (3 mM), the overshoot of the spike potential increased by about 10mV. With high concentration (10-30 mM), the overshoot was increased more and the repolarization was prolonged. The rate of rise of the spike potential increased by 3 mM TEA, but higher concentrations did not cause further increase.
2. Membrane potential was not changed by TEA nor was the electrotonic potential in response to the hyperpolarizing current affected. In the Mn-Locke solution, where Ca was substituted with 2.2 mm Mn and spike generation was abolished, the electrotonic response to the depolarizing current became larger when TEA was applied.
3. The spike potential, which had been once abolished in the Mn-added Locke solution, reappeared by applying TEA. TEA did not restore the spike generation in Cd-treated tissue.
4. Spike potential in Locke solution with Mn and TEA-added was gradually suppressed by repetitive electric stimuli with 1 Hz. It was restored by interposing longer intervals or by raising external Ca concentration.

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