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

Chi Te Lin, Yi Ju Tsai, Seu Hwa Chen, Hsin Ying Wang, Lung Huang Lin, June Horng Lue

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3 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)102-111
Number of pages10
JournalJournal of Chemical Neuroanatomy
Issue number2
Publication statusPublished - Oct 2010



  • C-Fos
  • DRG
  • Electrical stimulation
  • NT-3
  • Streptozotocin

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Medicine(all)

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