Cross Talk of BDNF and GDNF in Spinal Substantia Gelatinosa (Lamina II): Focus on Circuitry

BDNF and GDNF display the notable qualities of undergoing a regulated secretion in neurons and being anterogradely transported to nerve terminals, where they can modulate fast synaptic transmission. That BDNF positively modulates nociception and/or pain is today widely accepted, as the growth factor can start and maintain physiological and pathological pain. The contribution of GDNF to nociception is by far most elusive, but evidence is accumulating that the molecule displays analgesic activity, at least in rodents. Here I resume the current knowledge on the spinal cord circuits in which these two factors may act as modulators of pain-related synaptic transmission, focusing on their structural and functional interplay in the regulation of nociception and pain.