Miniature synaptic potentials recorded intracellularly from Purkinje cell dendrites in guinea pig cerebellar slices.

Intracellular recordings from Purkinje cell dendrites in guinea pig cerebellar slices revealed the existence of miniature spikes with various amplitudes, which were firing apparently without any externally applied stimulations. These spikes were in a hyperpolarizing direction at a resting membrane potential, and their apparent reversal potential was at about -60 mV, indicating their inhibitory nature. Based on the blocking actions of high-Mg2+, tetrodotoxin and amino acid antagonists such as bicuculline etc., these spikes were suggested to be inhibitory synaptic potentials generated by cerebellar interneurons.