| Reference code: | PT/FB/BL-2000-067.08 |
| Location: | Arquivo PCA - Pasta 10/2000
|
Title:
| Noxious evoked c-fos expression in brainstem neurons immunoreactive for GABAB, µ-opioid and NK1 receptors
|
| Publication year: | 2002
|
URL:
| http://fens2002.neurosciences.asso.fr/pages/posters/R6/A183_15.html
|
| Abstract/Results: | ABSTRACT:
Pain processing is modulated at several brainstem regions through various neurochemical systems. Pharmacological studies have shown that local instillation of agents that interfere with distinct receptors, differentially affect responses to pain. However, characterisation of local nociceptive neurones as to their surface receptors was never attempted. This study investigates the nociceptive nature of brainstem neurones containing mu-opioid, GABAB and NK1 receptors, using noxious-evoked expression of the c-fos proto-oncogene.
Male Wistar rats were anaesthetised with sodium pentobarbital (50mg/Kg) and subjected to noxious mechanical stimulation of the hindlimb (stimulated group). Two hours after, the animals were perfused. Frozen sections of the brain were immunoreacted for each receptor, by the avidin-biotin-DAB method, and for the Fos protein, by the avidin-streptavidin-fast blue method. In brainstem regions with raises in Fos expression as compared to controls (perfused after 2 hours of anaesthesia), the proportions of neurones double-labelled for each receptor and for Fos protein were determined in the total number of neurones expressing the receptor.
For mu-opioid receptor, double-labelled cells increased in stimulated animals at the ventrolateral medulla (VLM), spinal trigeminal nucleus (Sp5C), dorsal portion of the parabrachial nucleus (DPB) and A5 noradrenergic region. The proportion of GABAB double-labelled cells was increased in the VLM, Sp5C, nucleus of the tractus solitarii, dorsal reticular nucleus, ventral reticular nucleus, raphe obscurus nucleus and DPB. No differences were detected for NK1 receptor -immunoreactive cells. These results point to a differential involvement in pain processing of neurones displaying mu-opioid, GABAB and NK1 receptors at different pain control centres. (Supported by Gulbenkian Pain Programme and Bial Foundation).
|
| Accessibility: | Document does not exist in file
|
Language:
| eng
|
Related objects:
| PT/FB/BL-2000-67.03
|
| Author: | Pinto, M.
|
Secondary author(s):
| Tavares, I., Castro-Lopes, J. M., Lima, D.
|
Document type:
| Online abstract
|
Number of reproductions:
| 1
|
Reference:
| Pinto, M., Tavares, I., Castro-Lopes, J. M., & Lima, D. (2002). Noxious evoked c-fos expression in brainstem neurons immunoreactive for GABAB, µ-opioid and NK1 receptors. FENS Abstr.1, 465.
|
| Indexed document: | No
|
| Keywords: | Psychophysiology / Pain modulation / Sensory systems
|
|