Krotov V, Agashkov K, Krasniakova M, Safronov BV, Belan P, Voitenko N. Segmental and descending control of primary afferent input to the spinal lamina X.
Pain 2022;
163:2014-2020. [PMID:
35297816 PMCID:
PMC9339045 DOI:
10.1097/j.pain.0000000000002597]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 01/03/2022] [Accepted: 01/20/2022] [Indexed: 02/04/2023]
Abstract
ABSTRACT
Despite being involved in a number of functions, such as nociception and locomotion, spinal lamina X remains one of the least studied central nervous system regions. Here, we show that Aδ- and C-afferent inputs to lamina X neurons are presynaptically inhibited by homo- and heterosegmental afferents as well as by descending fibers from the corticospinal tract, dorsolateral funiculus, and anterior funiculus. Activation of descending tracts suppresses primary afferent-evoked action potentials and also elicits excitatory (mono- and polysynaptic) and inhibitory postsynaptic responses in lamina X neurons. Thus, primary afferent input to lamina X is subject to both spinal and supraspinal control being regulated by at least 5 distinct pathways.
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