Glycine receptors and brain development

Abstract

Glycine receptors (GlyRs) are ligand-gated chloride ion channels that mediate fast inhibitory neurotransmission in the spinal cord and the brainstem. There, they are mainly involved in motor control and pain perception in the adult. However, these receptors are also expressed in upper regions of the central nervous system, where they participate in different processes including synaptic neurotransmission. Moreover, GlyRs are present since early stages of brain development and might influence this process. Here, we discuss the current state of the art regarding GlyRs during embryonic and postnatal brain development in light of recent findings about the cellular and molecular mechanisms that control brain development.

Keywords: GlyRs; brain development; cortex; glycine; glycine receptors; hippocampus; interneurons; migration.

FIGURE 1

Glycine receptors and brain development. Glycine receptors control different processes during pre and postnatal development of the brain. During embryonic development, studies suggest that GlyRs are involved in neurotransmitter release and the control of cell migration. Migrating interneurons are schematized in green while radially migrating cells are shown in orange. Postnatal functions depend on the depolarizing or hyperpolarizing action downstream GlyRs activation. Initially, GlyRs mediate excitation and promote neurotransmitter release and synaptic communication. Later, GlyRs act as inhibitory and take part in inhibitory synapses. E, embryonic day; P, postnatal day, CR, Cajal–Retzius cells; PP, pre-plate; CP, cortical plate; SVZ, sub-ventricular zone; VZ, ventricular zone; IZ, intermediate zone; GlyRs, glycine receptors; V, voltage; I, current; IPSCs, inhibitory postsynaptic currents.