Pharmacological actions of various aminoacids and choline derivatives on the cortical activity of rabbits and cats were tested electrophysiologically.
1. Among aminoacids, only ω-aminoacids have been found to have pharmacological action on the cortex. Their shorter chain series showed inhibitory action. The inhibitory action of GABA was ca. 13 times stronger as that of β-alanine. Whereas, ε-aminocaproic acid showed an excitatory action. The excitatory action of 10%ε-amino-caproic acid was completely inhibited by 1% GABA.
2. GABA-Ch, glutamyl-choline and carbamyl-choline suppressed the primary sensory evoked potential and the direct cortical response. Among them, GABA-Ch showed the most powerful inhibition.
3. In the inhibition on metrazol spike, GABA-Ch was about 1000 time as active as GABA: glutamyl or carbamyl choline was about half or one-third as active.
4. By intravenous injection, the inhibitory action of GABA on seizures induced by metrazol was compared with that of sodium phenobarbital. Its inhibitory effect was prompt and much stronger than that of phenobarbital.
5. Among isomers of GABA, only β-aminoisobutyric acid showed a slight inhibitory action.
6. GABA and β-aminoisobutyric acid could elicit surface positive potentials. The phase-inverting action of GABA on spikes induced by metrazol or β-aminocaproic acid was remarkable.
GABA-Ch or other cholines did not show such effect.
7. A characteristic action of GABA on the electrical activity of the cortex seems to be phase-inverting.

View full abstract

Alternating current (50 cycles) was applied to the electrochemical model of excitation consisting of an iron core coated with the excitable membrane and immersing solution such as nitric acid or NaNO₃ solution which was so prepared as to exert weak action of membrane formation, and change in the amplitude of the alternating current indicating change in impedance, and change in membrane potential were recorded to observe the stimulating action of alternating current. And the following results were obtained.
1. Change in potential and impedance of the core produced by continuous flow of alternating current was similar to that observed with direct current.
2. Stimulated process and change in impedance which were observed when, following the first current, the second was applied with different intervals between them, that is, the summation of stimulating action, were similar to those observed with the summation of two rectangular shocks.
Discussing the above results it was concluded that the advance in the stimulated process promoted by a phase of alternating current in which it was directed towared the core would not be brought back to the initial level by the reverse phase, but would remain in some degree, and consequently that, when summated by application of many cycles, it would at last evoke excitation.

View full abstract

The febrile and the leucocytotic response of rabbits on intravenous injection of typhoid-paratyphoid vaccine were studied in relation to the adrenal cortex.
1. After adrenalectomy the febrile response remained unaltered, but the leucocytotic response failed to appear. The latter response necessitates the presence of glycocorticoids.
2. Independent existence of “endogenous pyrogenic” and “leucocytosis-inducing factor” in response to vaccine could be demonstrated by passive transfer technique. The development of the “leucocytosis-inducing factor” has a close causal relation to glycocorticoids.
3. In the tolerant state the leucocytotic response was markedly reduced. Cortisone-pretreatment could restored it in full magnitude.
The possibility that the vaccine administered leaves a susceptible state for glycocorticoids to induce leucocytosis was mentioned. And it was suggested that this effect of vaccine will be diminished in the tolerant state.

View full abstract

Recording of transmembrane resting and action potentials of interneurons and motoneurons by microelectrodes was used to study reticular formation facilitatory and inhibitory action. Both facilitation and inhibition of motoneurons occurred without detectable change in resting membrane potential. During facilitation the action potential rose earlier from the postsynaptic potential as though a change in threshold potential had occurred. Miniaturepotentials associated with reflex activation of motoneurons were seen and these were increased in number and fused as activation occurred during facilitatory action of the reticular formation. Reticular formation stimulation caused some motoneurons which normally were not excited by any of the orthodromic volleys to participate in one of the reflexes but in only one. Interneurons were found to be activated by more than one reflex and reticular formation facilitatory action increased the number of afferent nerve to which they would respond. Interneurons apparently participated in both inhibitory and facilitatory actions of the reticular formation. The various forms of interneuron participation in reticular formation actions were discussed. Activity of interneurons aroused by brief single pulse stimulation of the reticular formation lasted for over 500 milliseconds and could be considered to be a major factor in the prolonged effect of reticular formation stimulation on the reflex pathway. Recordings were made from anterior horn neurons which resembled Renshaw cells in activity. They were found to be inhibited by stimulations of the reticular formation which facilitated reflex action. Activity of other anterior horn neurons were described and discussed.

View full abstract

Employing single myelinated fibres prepared from toad's sciatic-peroneal nerve as material, observations were made on the graded nodal responses elicited in NaCl-deficient media.
When the NaCl-concentration was made gradually smaller than the critical for conduction, first the duration of activity became shorter, and then, in addition, the size became graded. From the relation obtained between the response size and the stimulus intensity, it was supposed that there exists a certain threshold for excitation distinguished from that of conduction, and that this threshold gets higher with smaller NaCl-concentration of the external fluid, to attain practically infinity at about 1/10 of the critical concentratio for conduction. This means that there is a certain critical NaCl-concentration for excitation, distinguished from that for conduction by a mach lower value.

View full abstract

1. The effect of tetraethylammonium (TEA) ions on toad's spinal motoneurons was studied with intracellular microelectrodes.
2. The falling phase of the action potential was markedly prolonged after TEA application. The time-course of this phase was unstable and liable to change by electrotonus and temperature.
3. EPSP was first increased after TEA. In some motoneurons, spontaneous generation of action potentials was not infrequent. Single orthodromic stimuli caused violent irregular discharges from these motoneurons.
4. The action potential generated antidromically had much longer falling phase than that generated orthodromically. Early termination of the falling phase could be brought about by superimposed PSP's, when an antidromic stimulation was followed by an orthodromic stimulation at suitable time intervals.
5. The PSP's responsible for this abolishment of action potential are considered to be of inhibitory nature (IPSP) and the mechanism of the abolishment was discussed.
6. At later stages of TEA application, single shocks given to a dorsal root failed eventually to fire the motoneurons. This was caused either by attenuated PSP's or by hyperpolarizing PSP's which then became predominant.

View full abstract

Some discussions were made on the alteration of estrus cycle and histological changes in various organs caused by excessive training to albino rats.
In the lightly or moderately trained group, the sexual cycle rotates regularly and even if it had been irregular prior to exercise, it became regular with training. In heavily trained group, there occurred an irregularity in the sexual cycle associated with the conspicuous decrease in body-weight.
In general, most organs showed the figure of hyperfunction in the early stage of training and degeneration or atrophy in later stage. Among others, thymus is the most fragile tissue, and salivary gland and testicle gland are the most resistant tissues against excessive exercise. The histological changes in intestine and kidney were very severe for their comparatively slight functional disturbances.

View full abstract

A new concept relating to the fundamental conditions of the effective stimulus to a living excitable system is suggested: the stimulus can be regarded as being transformed in the system to its response, and the property of the system is quantitatively represented by the “transforming action” defined in the following relation:
(0.0.2)(Stimulation)·(System)=(Response),
i.e.:
(4.1)(System)=(Response)/(Stimulation),
where the parenthesis shows a certain quantitative representation of the term enclosed and (System) means that of the “transforming action”. Let the threshold and the “transforming action” concerning the strength of the stimulus be a and G₀ respectively; then
(1.0.1) G₀=1/a
is obtained. Here, G₀ is no other than the well-known concept as the excitability of the living excitable system.
The “transforming action” G_-1 definable by concerning the strength-duration curve of the stimulus is
(2.6) G_-1=G₀/(τ+t₀),
where t₀ and τ show the utilization time and chronaxie respectively. Let us take here the chronaxie as the special case of the utilization time, i.e.t₀=τ;
then
(2.6.1) G_-1=G₀/2τ
(2.6.2)=1/2G₀·Gτ,
where
(2.8)Gτ=1/τ.
The reverse value of the chronaxie Gτ shows, therefore, a characteristic property of the system definable by considering the time-or duration-factor of the stimulus.
The “transforming action” G1, which is defined concerning the accommodation phenomenon, is
(3.3) G1=1/m
or
(3.3.1) G1=λG₀,
where m and A show the “minimal gradient” and the “accommodation constant” of the system respectively. Thus the reverse value of the “minimal gradient” and the “accommodation constant” itself may be said to show a characteristic property concerning the phenomenon of the accommodation.
The relation shown by the equation (0.0.2) is not only analogous to the following relation:
(4.4.2)(Cause)·(System)=(Effect),
which is definable by the causality law, but also to (4.2.1) and (4.4.1) shown in the physical system in general:
(4.2.1)(Stress)·(System)=(Strain)
(4.4.1)(Input, External force)·(System)=(Output, Response).
Even in the complicated physical linear system, it is also shown that the above relation (4.4.1) exists, when the Laplace transforms of the input and transfer function in the system are applied. In addition, if the Fourier transforms of them are taken as the special case of the Laplace transform, this relation becomes analogous to (0.0), which was obtained previously by the author (4) and the author et al.(5, 6) as showing the characteristic property of the brain wave generator in the brain.

View full abstract

1. Tonic vasomotor discharges were observed in the toad's splanchnic nerve, which were sometimes grouped synchronously with the heart beat.
2. Electrical stimulation of various nerves evoked first an increase of the discharge (excitation) and thereafter a silent period (inhibition).
3. After the medulla oblongata had been removed the inhibition was no longer observed and stimulation effected the excitation phase only. After further removal of the upper spinal cord stimulation did not evoke any response in the splanchnic nerve, though the tonic discharge was still observable.
4. Almost similar discharge patterns and responses were observed with the medulla oblongata and spinal cord (the medullospinal preparation) which had been excised with the splanchnic nerve and kept in a Ringer's bath under aeration.
5. On the basis of the above stated results the automaticity of the segmental vasomotor center and the location of the higher vasomotor centers of this animal are discussed.

View full abstract

In decerebrate and non-decerebrate cats the impulses from the short ciliary nerve were recorded. From the changes of the impulse frequency following the intravenous injection of adrenalin, the rôle of the pupillo-constrictory centers on the adrenalin-mydriasis and-miosis was studied.
1) In non-decerebrate cats the impulses from the short ciliary nerve were inhibited for several minutes by adrenalin.
2) In decerebrate cats the effect of adrenalin was reversed to excitatory effect.
3) In the cats administered chlorpromazine a similar excitatory effect to that in decerebrate cats was elicited by adrenalin.
4) From these results the mechanism of the action of adrenalin upon the pupillo-constrictory centers was discussod.
5) In decerebrate cats with no blood stream of the eye, the pupil was constricted by i.v. injection of adrenalin. This is a miosis of the central origin.

View full abstract

Human perspiration on a skin area of 20cm.² was recorded continuouslyby the use of a sensitive resistance hygrometer and it was found that the rateof sweating changed periodically with a cycle of a few seconds. Furthermore, evidence was presented that these variations occurred coincidently not onlyon the symmetrical parts of the chest, but also on the forehead and the thighindependently of the regional differences in sweat volume. A phenomenon ofhemihidrotic sweating induced reflexly by the skin-pressure was reconfirmed.Under this reflex state, the same periodic variations were still found on theside pressed and the opposite side, although the sweating was facilitated onthe latter and inhibited on the former. The cyclic variation of sweating maybe due to periodical contractions of myoepithelium, and the innervations ofwhich must differ from those of secretory sweat cells.

View full abstract

The cellular membrane potential of the injured cardiac muscle fiber of the dog was recorded, and its various electrical properties were investigated.
(1) Injury was caused by either of a mechanical compression with a glass tube, burn, and a ligature with a thread. The injured region was unable to impale, but the cells around there could be examined, and showed diminished RP, rise velocity decrease or disappearance of OS of AP. The greater the distance from injury, the less was the degree of impairment.
(2) A short period of hyperpolarization altered neither OS nor rise velocity.
(3) Membrane resistance of the injured cells decreased remarkably.
(4) By injury the threshold (rheobase) was elevated to a higher level as shown in the strengh-duration curves. Absolute refractory period was prolonged until a later phase of more than 80% repolarisation.
(5) There findings were discussed and the author would interprete as follows: the injured membrane loses its ion-selective ability and becomes leaky to ions.

View full abstract