Differential expression of NK1 and GABA(B) receptors in spinal neurones projecting to antinociceptive or pronociceptive medullary centres

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Castro, AR (Author) Other; Carla Morgado (Author) FMUP; Deolinda Lima (Author) FMUP; Isaura Tavares (Author) FMUP

Journal

Title: Brain Research Bulletin

Vol. 69

Pages: 266-275

ISSN: 0361-9230

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 18 Citations

Other information

Authenticus ID: P-004-M94

DOI: 10.1016/j.brainresbull.2005.12.004

Abstract (EN): The balance between excitatory and inhibitory input exerted upon spinal cord neurones that belong to spinofugal pathways determines the ultimate type of information transmitted to the brain. We compared the relative expression of NK1 and GABA(B) receptors in two spinomedullary pathways targeting an antinociceptive area and a pronociceptive centre, respectively, the lateral part of the caudal ventrolateral medulla (VLMlat) and the dorsal reticular nucleus (DRt). Spinal cord sections of rats injected in the VLMlat or DRt with the retrograde tracer cholera toxin subunit B were triple-immunoreacted for the tracer, NK1 receptors and GABA(B) receptors. The dorsal horn neurones labelled from the VLMlat mainly co-localized the two receptors while those labelled from the DRt mainly expressed GABA(B) receptors, which was particularly evident in neurones of laminae IV-V. The morphological classification of lamina I neurones projecting to the VLMlat showed that fusiform, flattened and pyramidal cells mainly co-localized NK1 and GABA(B) receptors. As to lamina I neurones projecting to the DRt, multipolar neurones mainly expressed GABA(B) receptors while the majority of flattened and pyramidal neurones co-localized NK1 and GABA(B) receptors. The present results suggest that the expression of NK1 and GABA(B) receptors varies in neurones participating to different spinofugal pathways. The importance of the present findings in the knowledge of the endogenous supraspinal pain control system is discussed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10