The Relationship Between Glycine and Gephyrin in Synapses of the Rat Spinal Cord

The study investigated the relationship between gephyrin, a protein associated with glycine receptors, and glycinergic boutons in the rat spinal cord. Using immunogold labeling, researchers found that a significant majority of synapses presynaptic to gephyrin-immunoreactive sites were enriched with glycine-like immunoreactivity, with proportions of at least 83% in laminae I and II, 91% in lamina III, and 98% in lamina IX. This indicated that glycine was a transmitter at these synapses, although gephyrin was sometimes present at non-glycinergic synapses, suggesting caution in using gephyrin as a sole marker for glycinergic synapses. Additionally, many boutons in the dorsal horn were found to be both glycine- and GABA-immunoreactive, indicating the use of both amino acids as inhibitory transmitters. This dual use may play a crucial role in regulating information flow from hair follicle afferents to other spinal neurons.