The glycine receptor is functionally expressed in migratory interneurons and influences early cortical development

The strychnine-sensitive glycine receptor (GlyR) is a member of the ligand-gated ion channel superfamily. In the adult, the GlyR is known to mediate fast inhibitory neurotransmission in the spinal cord and in the brainstem. The GlyR has also been described in the embryonic cortex after embryonic day 19 (E19) (Flint et al., 1998) where it could participate in developmental processes, but its presence at earlier stages has not been documented. Since other neurotransmitter systems, i.e. GABA and its receptors, are known to be potent signals that control corticogenesis (Nguyen et al., 2001; Ik-Tsen et al., 2007), we wondered if glycine and its GlyR could also fulfill such a function. In this study, we analyze GlyR expression and its physiological function in the early development of the cortex using in vitro cultures of embryonic day 13 slices, patch-clamp, two photon microscopy and immunocytochemistry.