Early expression of injury-induced neuropeptide Y in primary sensory neurons and the cuneate nucleus in diabetic rats with median nerve transection
Journal
Journal of Chemical Neuroanatomy
Journal Volume
40
Journal Issue
2
Pages
102-111
Date Issued
2010
Author(s)
Abstract
In this study we examined the temporal changes in neuropeptide Y (NPY) expression in dorsal root ganglion (DRG) neurons and cuneate nucleus (CN) in streptozotocin (STZ)-induced diabetic rats with or without median nerve transection (MNT). Numerous NPY-like immunoreactive (NPY-LI) neurons and fibers were detected in the DRG and CN of the diabetic MNT (DMNT) rats respectively, but not in those with diabetes-alone. Following MNT, the time-course of NPY expression pattern in the diabetic DRG and CN was similar and both peaked at 2 weeks, which was earlier than those in the non-diabetic MNT rats. Consequently, the expression of neurotrophin-3 (NT-3) immunoreactivity in DRG neurons was coincidentally decreased and reached the nadir at 2 weeks in the diabetic MNT rats, which was also earlier than that in the non-diabetic MNT rats. Following electrical stimulation of the injured nerves, the number of NPY-LI fibers became attenuated and the induced c-Fos-LI cells concurrently appeared in the ipsilateral CN. In the diabetic CN, the number of c-Fos-LI cells also peaked at 2 weeks after MNT, which was consistent with the temporal pattern of changes in NPY expression. The results suggest that in diabetes, MNT induced NPY expression via the reduction of NT-3, and electrical stimulation of the injured median nerve evoked the release of NPY and accordingly more c-Fos-LI cells were identified in the CN. Furthermore, this study demonstrated early NPY and c-Fos expression in the diabetic rats after MNT, suggesting that the development of neuropathic signs may be advanced in hyperglycemic rats. ? 2010 Elsevier B.V.
SDGs
Other Subjects
neuropeptide Y; neurotrophin 3; protein c fos; neuropeptide Y; neurotrophin 3; animal experiment; animal model; animal tissue; article; controlled study; cuneate nucleus; immunoreactivity; male; nerve fiber; nerve injury; nerve transection; neuromuscular electrical stimulation; nonhuman; priority journal; protein expression; rat; sensory nerve cell; spinal ganglion; streptozocin diabetes; analysis of variance; animal; confocal microscopy; electrostimulation; experimental diabetes mellitus; immunohistochemistry; median nerve; medulla oblongata; metabolism; sensory nerve cell; Sprague Dawley rat; time; Analysis of Variance; Animals; Diabetes Mellitus, Experimental; Electric Stimulation; Ganglia, Spinal; Immunohistochemistry; Male; Median Nerve; Medulla Oblongata; Microscopy, Confocal; Neuropeptide Y; Neurotrophin 3; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Sensory Receptor Cells; Time Factors; Analysis of Variance; Animals; Diabetes Mellitus, Experimental; Electric Stimulation; Ganglia, Spinal; Immunohistochemistry; Male; Median Nerve; Medulla Oblongata; Microscopy, Confocal; Neuropeptide Y; Neurotrophin 3; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Sensory Receptor Cells; Time Factors
Type
journal article