Nociceptive spinal neurons expressing NKI and GABA(B) receptors are located in lamina I

• Type: Article in International Scientific Journal
• Date: 2004

Authors

Castro, AR (Author) Other; Pinto, M (Author) Other; Deolinda Lima (Author) FMUP; Isaura Tavares (Author) FMUP

Journal

Title: Brain Research

Vol. 1003

Pages: 77-85

ISSN: 0006-8993

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 16 Citations

Scopus - 19 Citations

Other information

Authenticus ID: P-000-AVE

DOI: 10.1016/j.brainres.2003.12.027

Abstract (EN): The nociceptive nature of spinal dorsal horn neurons expressing NK1 and gamma-aminobutyric acid (GABA)(B) receptors was evaluated in the rat. Immunodetection of the Fos protein, induced by noxious mechanical stimulation of the skin, was combined with immunocytochemistry for NK1 or GABA(B) receptors (double-immunostaining study) or both receptors (triple-immunostaining study). Neurons double-labeled for Fos and for each receptor largely prevailed in lamina I. The proportions of Fos-positive cells immunostained for NK1 or GABA(B) receptors were higher in lamina I than in the remaining spinal laminae. More Fos-positive cells were immunoreactive (IR) for GABA(B) receptors than for NK1 in all dorsal horn laminae. In the triple-immunostaing study, co-localization of NK1 and GABA(B) receptors occurred only in lamina I and was higher in neurons expressing Fos. As to the morphological lamina I cell class, NK1-positive cells belonged mainly to the fusiform. type while similar proportions of fusiform, pyramidal and flattened NK1 neurons expressed GABA(B) receptors. No differences were found between those cell types as to the degree of nociceptive activation. The present results suggest that the co-localization of NK1 and GABA(B) receptors is a common feature of fusiform, pyramidal and flattened neurons in lamina I. Considering the participation of the three cell classes in various ascending systems, it is concluded that a simultaneous action of substance P (SP) and GABA may play an important role in the modulation of nociceptive input supraspinally transmitted from lamina I.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9