Fig. 1.

The glycinergic system. a Inhibitory (strychnine-sensitive) glycine receptors are pentameric chloride-permeable ion channels. b Each subunit has four transmembrane segments and two cys-loops in the extracellular domain. c Five genes encode for glycine receptor subunits. The α4 subunit gene (GLRA4) is a pseudogene in humans. d Sagittal section through the mouse brain stained with an antibody against GlyT2 illustrates the distribution of glycinergic axon terminals (modified from ref. [10]). e Distribution of the glycine receptor α3 subunit (green) in the mouse spinal cord (modified from ref. [14]). Red, distribution of gephyrin. d and v indicate dorsal and ventral direction, respectively. f Contribution of glycine receptors to the total evoked IPSC in excitatory neurons of the superficial mouse spinal dorsal horn. In the majority of neurons, the contribution of glycine receptors to the IPSC amplitude dominates over that of GABA.

Modified from ref. [8]