Different presynaptic nicotinic receptor subtypes modulate in vivo and in vitro the release of glycine in the rat hippocampus

► Nicotine in vivo was able to evoke endogenous glycine release in rat hippocampus. ► Nicotinic control in vivo was mediated by different receptor subtypes. ► Nicotine elicited glycine overflow also from hippocampal synaptosomes in vitro. ► 5IA85380 and Choline were able to induce a glycine overflow from hippocampus. ► Our results indicate the existence of DHβE resistant α4β2 subtypes.