[Elements concerning the cellular organization of glycine receptors dependent of chlorine]

Glycine is one of the main inhibitory neurotransmitter in the central nervous system of vertebrates where it acts by activating a chloride conductance. The distribution of glycine receptor at the neuronal surface was analysed by immunocytochemistry with monoclonal antibodies raised against the purified receptor. In the rat spinal cord as well as in other areas of the central nervous system, these receptors are localized at the postsynaptic membrane and are concentrated in front of the presynaptic release sites. Thus, they define functional microdomains at the plasma membrane. A similar organisation was observed in a motor command neuron: the Mauthner cell of Teleosts. Further, in this model, a quantitative analysis using confocal microscopy has established that the postsynaptic microdomains are arranged according to a somatodendritic gradient with the larger clusters at the tip of the dendrites. The use of primary cultures of rat or mouse spinal cord neurons has allowed to study the ontogenesis of the glycine receptor. We have shown that these receptors are, here also, organized in clusters present at the neuronal surface and that the formation of these aggregates occurs simultaneously to the establishment of synaptic contacts.