Comparison of glycine- and GABA-evoked currents in two types of neurons isolated from the rat striatum

Strychnine-sensitive glycine-activated currents and gamma-aminobutyric acid (GABA)-activated currents were compared in two types of neurons acutely isolated from striatal slices by vibrodissociation: large cells, presumably cholinergic giant aspiny neurons (GAN) and medium sized cells, presumed medium spiny neurons (MSN). Whole cell voltage clamp and concentration jump techniques were used. All cells responded to glycine (10-1000 microM) and GABA (2-100 microM), in MSN and GAN the maximal responses to glycine were 50 and 120% of the GABA response, respectively. GABA- and glycine- responses were additive and blocked selectively by bicuculline (1 microM) and strychnine (50 nM), respectively. These results predict the presence of alpha- and beta-subunits of the glycine receptor in the striatum.