Reflex Motor Discharges in Single Nerve Fibres of the Frog in Strychnine Poisoning and in other Convulsive States

Publisher Website
Google Scholar
Abstract
Summary.: The maximal frequency (at room temperature) of reflex impulsation in single nerve fibres of the frog was examined. It was found to vary in different conditions being lowest (up to 125 imp/sec.) in normal reflexes of a spinal frog, probably somewhat higher in brain‐stem and chloralose frogs and distinctly higher in convulsive states especially in strychnine cramps viz. up to 300 imp/sec.The peculiar form of activity in single fibres under strychnine and cold convulsions was also investigated. It could be stated that during fully developed strychnine and cold cramps the single fibre neurogram consisted of high frequency outbursts of impulses appearing 5–10 times per sec., the groups being separated from each other by a more or less distinct silent period. The impulse groups in different fibres showed a considerable synchronism.In the discussion it is pointed out that increased irradiation of reflexes e. g. in brain‐stem or strychnine frogs compared with spinal, normal frogs usually corresponds to a raised “functional” frequency maximum of the motor nerve cell. As it is known that strychnine as well as cooling of the cord partly abolishes the one‐way conduction in synapses leading to maximal irradiation of reflexes, the possibility to explain some other phenomena in convulsive states on this basis was considered. According to GESELL the number of impinging signals and of activated synapses at the dendritic part of the neuromembrane causes a potential gradient between the dendritic and axon hillock parts of the neurone, that determines the degree of activity of a nerve cell. If this theory is applied on the strychnine effects, it might be possible to interpret the excitatory action of strychnine on motor cortex and the strychnine reversing of inhibitory reflexes to excitatory as results of the failure of one‐way conduction in the cord caused by strychnine.

This publication has 16 references indexed in Scilit: