Strychnine-resistant mutual inhibition of renshaw cells

Abstract

Extracellular recordings were obtained from Renshaw cells in anaesthetized spinal cats. The effect of strychnine, administered either intravenously or by microelectrophoresis, was determined upon inhibition produced in a variety of ways. It was observed that the depressant action of glycine was readily antagonized by strychnine administered with small electrophoretic currents. Larger currents ejecting strychnine were invariably effective in reducing inhibition elicited by squeezing a hind paw, but mutual inhibition of Renshaw cells was resistant to strychnine administered either microelectrophoretically or intravenously. Various explanations of the strychnine resistance of mutual inhibition were considered and it was concluded that a likely explanation is that there may be postsynaptic receptors which are sensitive to glycine but are resistant to strychnine. It was thought that it is unlikely that these receptors are 'GABA' receptors. © 1972.