Journal article
Separate groups of dorsal horn neurons transmit spontaneous activity and mechanosensitivity one day after plantar incision
European journal of pain, Vol.13(8), pp.820-828
Received 24 June 2008; received in revised 10 October 2008; accepted 24 October 2008
09/2009
DOI: 10.1016/j.ejpain.2008.10.005
PMID: 19081275
Abstract
Dorsal horn neuron (DHN) sensitization can be induced and maintained by nociceptor activation. In previous studies, only a small increase in ongoing DHN activity was present immediately after plantar incision; yet, powerful activation of nociceptors was prominent 1 day after incision. In the present study, rats underwent plantar incision or sham surgery as control. One day later pain behaviors were measured; then DHN activity and response properties to mechanical stimulation were recorded in vivo. In some neurons with spontaneous activity, the incision was anesthetised using bupivacaine. Spontaneous activity was identified in 9 of 27 neurons in the control group and in 16 of 26 neurons (P < 0.05) in the incision group; the spontaneous activity in incised animals (19.1 ± 8.5 imp/s) was also greater than in controls (10.6 ± 6.1 imp/s, P < 0.05). For neurons without spontaneous activity, the responses to mechanical stimuli of the incision group were greater (P < 0.01); for neurons with spontaneous activity, there was no such difference. After bupivacaine injection, no difference was present in the amount of spontaneous activity between the two groups. This study demonstrates that 1 day after incision, DHN sensitization manifests in markedly increased spontaneous activities, enhanced responses to mechanical stimuli and expanded receptive fields (RFs). Separate groups of neurons appear to transmit spontaneous activity and enhanced responses to mechanical stimuli. Inhibition of spontaneous activity by blockade of afferent input indicates that the prolonged spinal hyperactivity remains largely dependent on the ongoing primary afferent activity. © 2008 European Federation of Chapters of the International Association for the Study of Pain.
Details
- Title: Subtitle
- Separate groups of dorsal horn neurons transmit spontaneous activity and mechanosensitivity one day after plantar incision
- Creators
- Jun Xu - University of IowaPhilippe Richebe - University of Iowa Hospitals and ClinicsTimothy J. Brennan - University of Iowa Hospitals and Clinics
- Resource Type
- Journal article
- Publication Details
- European journal of pain, Vol.13(8), pp.820-828
- Edition
- Received 24 June 2008; received in revised 10 October 2008; accepted 24 October 2008
- Publisher
- Blackwell Publishing Ltd
- DOI
- 10.1016/j.ejpain.2008.10.005
- PMID
- 19081275
- ISSN
- 1090-3801
- eISSN
- 1532-2149
- Number of pages
- 9
- Language
- English
- Date published
- 09/2009
- Academic Unit
- Surgery; Anesthesia
- Record Identifier
- 9984322958502771
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