当前位置： SCI文献检索 > BRAIN RESEARCH期刊下所有文献 > Glutamate and capsaicin effects on trigeminal nociception II: activation and central sensitization in brainstem neurons with deep craniofacial afferent input.

Glutamate and capsaicin effects on trigeminal nociception II: activation and central sensitization in brainstem neurons with deep craniofacial afferent input.

Abstract：

:We examined the effect of the peripheral application of glutamate and capsaicin to the temporomandibular joint (TMJ) in influencing the activation and central sensitization of TMJ-responsive nociceptive neurons in the trigeminal subnucleus caudalis/upper cervical cord (Vc/UCC). The activity of single neurons activated by noxious mechanical stimulation of the TMJ was recorded in the Vc/UCC of 49 halothane-anesthetized male rats. Cutaneous mechanoreceptive field (RF), cutaneous mechanical activation threshold (MAT), and TMJ MAT of each neuron were assessed before and after injection of 0.5 M glutamate (or vehicle) and 1% capsaicin (or vehicle) into the TMJ. A total of 49 nociceptive neurons (37 nociceptive-specific, 12 wide-dynamic-range) that could be activated by blunt noxious mechanical stimulation of the TMJ were studied. When injected alone, glutamate and capsaicin activated and induced central sensitization (reflected in cutaneous RF expansion and cutaneous and/or TMJ MAT reduction) in most Vc/UCC neurons. Following glutamate injection, capsaicin evoked greater activity and less cutaneous/TMJ MAT reduction compared with capsaicin alone, whereas capsaicin abolished all subsequent glutamate-evoked activity and depressed cutaneous RF expansion in most neurons. Glutamate effects on deep afferents and Vc/UCC neurons were analogous since glutamate sensitized afferent and neuronal responses to capsaicin but the desensitizing effects of capsaicin on glutamate-evoked excitability of Vc/UCC neurons contrast with the lack of capsaicin-induced modulation of glutamate-evoked afferent excitability [Lam, D.K., Sessle, B.J., Hu, J.W., 2008a. Glutamate and capsaicin effects on trigeminal nociception I: activation and peripheral sensitization of deep craniofacial nociceptive afferents. Brain Res. doi:10.1016/j.brainres.2008.11.029], suggesting that peripheral and central sensitization may be differentially involved in the nociceptive effects of glutamate and capsaicin applied to deep craniofacial tissues.

journal_name

Brain Res

journal_title

Brain research

authors

Lam DK,Sessle BJ,Hu JW

doi

10.1016/j.brainres.2008.11.056

subject

Has Abstract

pub_date

2009-02-09 00:00:00

pages

48-59

eissn

0006-8993

issn

1872-6240

pii

S0006-8993(08)02834-5

journal_volume

1253

pub_type

杂志文章

在线工具

Glutamate and capsaicin effects on trigeminal nociception II: activation and central sensitization in brainstem neurons with deep craniofacial afferent input.