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Spinal processing of noxious and innocuous cold information: differential modulation by the periaqueductal gray

Leith, J L, Koutsikou, Stella, Lumb, B M, Apps, R (2010) Spinal processing of noxious and innocuous cold information: differential modulation by the periaqueductal gray. Journal of Neuroscience, 30 (14). pp. 4933-4942. (doi:10.1523/JNEUROSCI.0122-10.2010) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:84446)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
https://doi.org/10.1523/JNEUROSCI.0122-10.2010

Abstract

In addition to cold being an important behavioral drive, altered cold sensation frequently accompanies pathological pain states. However, in contrast to peripheral mechanisms, central processing of cold sensory input has received relatively little attention. The present study characterized spinal responses to noxious and innocuous intensities of cold stimulation in vivo and established the extent to which they are modulated by descending control originating from the periaqueductal gray (PAG), a major determinant of acute and chronic pain. In lightly anesthetized rats, hindpaw cooling with ethyl chloride, but not acetone, was sufficiently noxious to evoke withdrawal reflexes, which were powerfully inhibited by ventrolateral (VL)-PAG stimulation. In a second series of experiments, subsets of spinal dorsal horn neurons were found to respond to innocuous and/or noxious cold. Descending control from the VL-PAG distinguished between activity in nociceptive versus non-nociceptive spinal circuits in that innocuous cold information transmitted by non-nociceptive class 1 and wide-dynamic-range class 2 neurons remained unaltered. In contrast, noxious cold information transmitted by class 2 neurons and all cold-evoked activity in nociceptive-specific class 3 neurons was significantly depressed. We therefore demonstrate that spinal responses to cold can be powerfully modulated by descending control systems originating in the PAG, and that this control selectively modulates transmission of noxious versus innocuous information. This has important implications for central processing of cold somatosensation and, given that chronic pain states are dependent on dynamic alterations in descending control, will help elucidate mechanisms underlying aberrant cold sensations that accompany pathological pain states.

Item Type: Article
DOI/Identification number: 10.1523/JNEUROSCI.0122-10.2010
Subjects: Q Science > QP Physiology (Living systems)
Divisions: Divisions > Division of Natural Sciences > Medway School of Pharmacy
Depositing User: Stella Koutsikou
Date Deposited: 25 Nov 2020 13:03 UTC
Last Modified: 16 Feb 2021 14:16 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/84446 (The current URI for this page, for reference purposes)
Koutsikou, Stella: https://orcid.org/0000-0003-2933-3637
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