GABA increases electrical excitability in a subset of human unmyelinated peripheral axons

A proportion of small diameter primary sensory neurones innervating
human skin are chemosensitive. They respond in a receptor dependent
manner to chemical mediators of inflammation as well as naturally
occurring algogens, thermogens and pruritogens. The
neurotransmitter GABA is interesting in this respect because in
animal models of neuropathic pain GABA pre-synaptically regulates
nociceptive input to the spinal cord. However, the effect of GABA
on human peripheral unmyelinated axons has not been established.