[Differences of behavior of DSCT neurons in decerebrate and barbiturate anesthetized cats (author's transl)]

Responses of dorsal spinocerebellar tract (DSCT) neurons to random electrical stimulation of peripheral nerves of the hindleg in decerebrate cats were studied using cross-correlation analysis of the output spike train. The spontaneous background discharge in barbiturate's cats had longer mean interspike interval than that in decerebrate cats, but there was no difference of the coefficient of variation in the two groups. This suggests that barbiturate has no effect on raising of the electrical threshold of the axon, but prolonging effect on interspike interval. Comparison of the conduction velocity showed to be slower in barbiturate's cats, so barbiturate reduces the conduction rate of the axon. The DSCT responses to the electrical stimulation of peripheral nerve in decerebrate cats were recorded in 60%, while 85% in barbiturate's cats. The reasons for this difference are that the DSCT cells in decerebrate cats are tonically inhibited from the pontine and bulbar reticular formation and the function of brain-stem reticular formation is suppressed by the barbiturate. Type 2 response in decerebrate cats, which represents reduced excitability of the DSCT cells, had inhibition with shorter initial peak latency and duration as compared to that in barbiturate's cats. This confirms the result of Eccles et al. that barbiturate in moderate dosage increases and prolongs the presynaptic inhibition.