Toluene decreases Purkinje cell output by enhancing inhibitory synaptic transmission in the cerebellar cortex

Toluene belongs to a class of psychoactive drugs known as inhalants. Found in common household products such as adhesives, paint products, and aerosols, toluene is inhaled for its intoxicating and euphoric properties. Additionally, exposure to toluene disrupts motor behaviors in a manner consistent with impairments to cerebellar function. Previous work has suggested a role of GABA in mediating toluene's neurobehavioral effects, but how this manifests in the cerebellar cortex is not yet understood. In the present study, we examined the effects of toluene on cerebellar Purkinje cell action potential output and inhibitory synaptic transmission onto Purkinje cells using patch clamp electrophysiology in acute rat cerebellar slices. Toluene (1 mM) reduced the frequency of Purkinje cell action potential output without affecting input resistance. Furthermore, toluene dose-dependently enhanced inhibitory synaptic transmission onto Purkinje cells, increasing the amplitude and frequency of inhibitory postsynaptic currents; no change in the frequency of action potentials from molecular layer interneurons was noted. The observed decreases in Purkinje cell action potential output could contribute to toluene-evoked impairments in cerebellar and motor functions.