Functional Organization of Cutaneous and Muscle Afferent Synapses onto Immature Spinal Lamina I Projection Neurons.
J Neurosci 2017 Feb 9;37(6):1505-1517. Epub 2017 Jan 9.
Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio 45267
It is well established that sensory afferents innervating muscle are more effective at inducing hyperexcitability within spinal cord circuits compared with skin afferents, which likely contributes to the higher prevalence of chronic musculoskeletal pain compared with pain of cutaneous origin. However, the mechanisms underlying these differences in central nociceptive signaling remain incompletely understood, as nothing is known about how superficial dorsal horn neurons process sensory input from muscle versus skin at the synaptic level. Using a novel ex vivo spinal cord preparation, here we identify the functional organization of muscle and cutaneous afferent synapses onto immature rat lamina I spino-parabrachial neurons, which serve as a major source of nociceptive transmission to the brain. Read More