Neuroscience 2005 Abstract
| Presentation Number: | 861.1 |
|---|---|
| Abstract Title: | Effect of p38 mitogen-activated protein kinase (MAPK) inhibitor on central sensitization in trigeminal subnucleus caudalis (medullary dorsal horn). |
| Authors: |
Xie, Y. F.*1
; Chiang, C. Y.1
; Park, S. J.1
; Hu, J. W.1
; Dostrovsky, J. O.2
; Sessle, B. J.1
1Faculty of Dentistry, Toronto, Canada 2ON, 124 Edward Street, M5G 1G6, |
| Primary Theme and Topics |
Neural Excitability, Synapses, and Glia: Cellular Mechanisms - Glia-neuron interactions -- Neuron-glial signaling |
| Secondary Theme and Topics | Sensory and Motor Systems<br />- Pain<br />-- Trigeminal processing |
| Session: |
861. Trigeminal Processing II Poster |
| Presentation Time: | Wednesday, November 16, 2005 8:00 AM-9:00 AM |
| Location: | Washington Convention Center - Hall A-C, Board # X33 |
| Keywords: | NOCICEPTION, MICROGLIA, METABOLISM, NEUROPLASTICITY |
We have demonstrated that astroglial activation is involved in the central sensitization induced in trigeminal subnucleus caudalis (Vc) nociceptive neurons by mustard oil (MO) application to the tooth pulp (Chiang et al. SfN Abst 518.10, 2004). The aim of this study was to test if microglia are also involved in central sensitization in Vc by the use of an inhibitor (SB203580) of p38 MAPK which is known to play a key role in the activation of spinal microglia. In urethane/a-chloralose-anesthetized adult male rats, extracellular recordings of single neuronal activity were made from nociceptive-specific (NS) neurons in Vc. The mechanoreceptive field (RF), mechanical activation threshold and responses to graded pinch or pressure of each neuron were assessed at baseline. Then 2 assessments were made at 5 and 15 min after a bolus application of SB203580 (i.t., 2.7 nmole in 10 µl saline) or continuous superfusion (i.t., 0.6 ml/hr) of saline (as control) onto Vc, and MO was next applied to the first maxillary molar pulp and 5 similar assessments at 10 min intervals were made. After saline pretreatment, MO application produced prolonged and significant neuroplastic changes reflecting central sensitization, i.e., increases in neuronal RF size and responses to graded pinch or pressure and a decrease in threshold (P<0.01-0.001, one-way RM ANOVA, n=6). SB203580 pretreatment significantly attenuated the MO-induced central sensitization (P>0.2-0.3, n=6). There were significant differences between the saline and SB203580 pretreatment groups in RF size, threshold and responses to mechanical stimuli (all P<0.001, two-way ANOVA). These results indicate that local activation of p38 mitogen-activated protein kinase in microglia may play an important role in the initiation of central sensitization in nociceptive dorsal horn neurons.
Supported by Supported by NIH DE-04786
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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