The European journal of neuroscience
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Comparative Study
Noxious-evoked c-fos expression in brainstem neurons immunoreactive for GABAB, mu-opioid and NK-1 receptors.
Modulation of nociceptive transmission at the brainstem involves several neurochemical systems. The precise location and specific characteristics of nociceptive neurons activated in each system was never reported. In this study, the presence of GABA(B), mu-opioid, and neurokinin-1 (NK-1) receptors in brainstem nociceptive neurons was investigated by double-immunocytochemical detection of each receptor and noxious-evoked induction of the c-fos proto-oncogene. ⋯ As for the NK-1 receptor, no significant differences were found between control and stimulated animals. According to these results, neurons expressing GABA(B), mu-opioid and NK-1 receptors at several pain control centres of the brainstem are differentially involved in processing nociceptive mechanical input. The data provide the definition of new supraspinal targets for selective modulation of nociceptive neurons in order to define better strategies of pain control.