Strychnine-sensitive glycine receptors in cultured primary neurons from rat neocortex.

After 1 day in vitro (DIV) glycine (1 mM) evoked chloride-dependent membrane currents in about 50% of primary cultured rat neocortical neurons and more than 98% of the cells were glycine-sensitive after 2 DIV lasting for at least up to 12 DIV which was similar to GABA chemosensitivity. Strychnine (IC50 40 nM) and picrotoxin (30 microM) but not bicuculline (50 microM) blocked the glycine-evoked currents. The results provide evidence for a very early expression of glycine receptors on cortical neurons leading to a powerful chloride channel-operating capacity during early development.