Synaptic Relationships Between Hair Follicle Afferents and Neurons Expressing GABA and Glycine-Like Immunoreactivity in the Spinal Cord of the Rat

The study investigated the synaptic interactions between hair follicle afferent terminals and neurons expressing GABA and glycine-like immunoreactivity in the spinal cord of rats. It was found that 94% of afferent boutons were postsynaptic at axo-axonic synapses, with 67% of presynaptic boutons being immunoreactive for both GABA and glycine, 24% for GABA alone, and 7% for glycine alone. A small percentage of dendrites postsynaptic to afferent boutons were immunoreactive for inhibitory neurotransmitters, with 3% for both GABA and glycine, 10% for glycine alone, and 87% for neither. The study suggested that glycine might act on dendrites postsynaptic to hair follicle afferent terminals, as these terminals do not express glycine receptors themselves.