Early expression of injury-induced neuropeptide Y in primary sensory neurons and the cuneate nucleus in diabetic rats with median nerve transection

Nitric Oxide Implicates c-Fos Expression in the Cuneate Nucleus Following Electrical Stimulation of the Transected Median Nerve

“…Although we found that following MNT the amount of nNOS expression was temporally parallel with that of NPY expression in the DRG and CN and that both peaked at 4 weeks [17,22], the interaction between NOS-LI and NPY-LI neurons remains uncertain. Four weeks after MNT, in agreement with previous studies, NOS-LI neurons were found mainly in small-sized DRG neurons [4,5], whereas NPY was primarily detected in the injured medium-and large-sized neurons [17,25]. Previous studies have shown that the produced NO could diffuse out of DRG neurons to neighboring cells to increase cyclic guanosine monophosphate (cGMP) levels in DRG satellite cells but almost not in DRG neurons [39][40][41].…”

“…It was demonstrated that the origin of the induced NPY-LI fibers in the CN was exclusively derived from the injured DRG neurons via primary afferent terminals (PATs) [22]. Furthermore, the results of pharmacological and morphological studies [23][24][25] have also shown that injury-induced NPY released from the injured median primary afferent terminals by electrical stimulation to significantly evoke c-Fos expression in the CTNs. The expressions of the proto-oncogene c-Fos and its protein product c-Fos have been widely used as a marker of neuronal activity, and as a neuronal marker of pain following noxious stimulation [26,27].…”