The glycine receptor (GlyR) is a member of the ligand-gated ion channel superfamily. The presence and function of glycine receptors in the adults it is well known, however, the presence of glycine receptor in the embryonic cortex has only been study after the embryonic day 19 (E19) (Flint et al., 1998) and there is no description about the physiological function of this receptor at early stages of cortical development. The development of the cortex during embryogenesis it is a complex process characterized by intense proliferation, cellular migration from the proliferative zones and differentiation that will end up with the generation cortical circuits. A wide range of factors are known to influence the different aspects of corticogenesis. Among those factors, neurotransmitters and ligand-gated ion channels have recently gained interest for being signals for central nervous system (CNS) development (Nguyen. et al., 2001; Ik-Tsen et al., 2007). In this study we have characterize the functional properties, by using the patch clamp technique, of GlyR mediated current during early stages of development (E13-E17) showing, for the first time, the presence of GlyR mediated currents in migrating neurons. The two main types of migrating neurons, the proyection neurons and interneurons express GlyR as soon as they start their migration to build the cortex. Along its migration the pharmacological properties of the receptor change as a possible effect of receptor maturation. The EC₅₀ for glycine in migrating cells before passing the cortico stratial junction was 154 ± 41and after entering the cortex it changed to 69 ± 12 mM. All these GlyR mediated currents were blocked by the traditional blockers of GlyR, strychnine and picrotoxinin. With regard to the physiological role of GlyR in corticogenesis it was assessed the possible effects in migration and proliferation and it was found that glycine GlyR blockade actively modulate cell migration and possibly also cell proliferation.