Neuronal hyperactivity at the spinal cord and periaqueductal grey during painful diabetic neuropathy: Effects of gabapentin

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Carla Morgado (Author) FMUP; Terra, PP (Author) Other; Isaura Tavares (Author) FMUP

Journal

Title: European Journal of Pain

Vol. 14

Pages: 693-699

ISSN: 1090-3801

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 40 Citations

Scopus - 42 Citations

Other information

Authenticus ID: P-003-48R

DOI: 10.1016/j.ejpain.2009.11.011

Abstract (EN): Painful diabetic neuropathy may be due to impairments in descending modulation of nociceptive transmission at the spinal cord. In the present study, streptozotocin diabetic rats (STZ rats) with neuropathic symptoms (mechanical hypersensitivity) were used to perform a time-course evaluation of neuronal activity at the spinal dorsal horn and at the periaqueductal grey matter (PAG), a major brainstem area of pain modulation. The expression of Fos protein, a marker of nociceptive activation, progressively increased at the spinal dorsal horn at 4 and 10 weeks. At the PAG, increases in Fos expression were detected until the 4th week, with a reversal to baseline values at 10 weeks in all areas except the ventrolateral PAG. Co-localisation of Fos with NeuN ascertained the neuronal nature of Fos-expressing cells at the spinal cord and PAG. Four weeks after diabetes induction, the effects of gabapentin (i.p. injection of 50 mg/kg, daily during 3 days) were assessed. Gabapentin decreased Fos expression at the spinal cord and PAG and reversed mechanical hypersensitivity. The present study shows that diabetic neuropathy is accompanied by a progressive increase of the spontaneous neuronal activity at the spinal cord. Changes in descending modulation of nociceptive transmission from the PAG are likely to occur during diabetic neuropathy, probably with exacerbation of facilitatory actions. The effects of gabapentin in reversing the behavioural signs of diabetic neuropathy and neuronal hyperactivity in the spinal cord and PAG reinforce the central causes of diabetic neuropathy and point to the central targets of the drug.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7