Pattern stimulation and action potential of frog skin (author's transl)]

Experiments were carried out to investigate the relationship between the pattern of stimulus of efferent or afferent nerve and the size of action potential of frog's skin. Two kinds of preparations were used: the excised nerve skin preparation and the spinal preparation. In the range of moderate intervals of stimuli, the size of skin action potential of the nerve-skin preparation became larger with the increase of number of stimuli, (i) during a definite period of stimulation with various frequencies, or (ii) during various long periods of stimulation with constant frequency. The size of potential depended not only on number of stimuli but also on their interval. The latter property may be called pattern-sensitive. In some state of preparation the size of potential evoked by a constant number of stimuli was nearly constant, being independent from stimulus frequencies, that is, pattern insensitive. Both kinds of results were obtained in cases of the spinal preparation. Michaelis-Menten's equation could be applied to describe the relation between the size of potential and the number of stimuli. However, there was no reason to interprete this relation with a simple concentration-effect relationship. Another hypothesis was then testoned on the supposition that the response is composed of sequentially superposed unitary processes each of which was promptly evoked by each stimulus and decayed exponentially. The calculated response curve reasonably fit with the observed data. Slower processes commonly called accomodation were excluded from the present discussion and only the effect of relatively short period of stimulation was examined.     

Analysis of nitrocompound pesticides by potentiography (author's transl)]

This paper describes a potentiographic technique developed for determining nitrocompound pesticides. The statistical analysis of the results showed that it is precise and accurate. Rapidity is another important characteristic of the developed potentiographic technique. It is not specific and for that in some cases a column chromatographic cleanup is necessary.     

The effect of asphyxia on the electrical and mechanical activities of the rat hindlimb muscles (author's transl)]

After asphyxia by clamping external iliac artery, the changes of electrical and mechanical activities of M. extensor digitorum longus and soleus were followed up. Although the action potential amplitude was decreased monotonously, a transient increase in twitch tension appeared, one or two minutes after start of asphyxia, which was seen more frequently and more remarkable in extensor than soleus. This was attributed to the different metabolic process of components contained in the muscle and also to their different population in two kinds of muscle fibres. It was suggested from the previous results obtained by us that the decrease of action potential amplitude, at least in the early period of asphyxia, was not due to membrane depolarization but to conformational change of Na-channel by anoxia.