Brain research. Molecular brain research
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Brain Res. Mol. Brain Res. · Dec 2005
Comparative StudyRegulation of two rat mas-related genes in a model of neuropathic pain.
The mas-related gene (Mrg) family is a large family of G-protein-coupled receptors which are variable in number depending on species. The so-called sensory-neuron-specific receptors (SNSRs) make up a subset of the Mrg family, and several of these have been implicated in nociceptive processes. To verify their specific localization in sensory ganglia, we have determined the expression patterns of two of them, rMrgA and rMrgC, in a panel of rat tissues. ⋯ These behavioral changes in tactile sensitivity were accompanied by significant decreases (10- to 100-fold) in the mRNA expression of both rMrgA and rMrgC exclusively in the L5 and L6 dorsal root ganglia ipsilateral to the SNL. In situ hybridization studies demonstrated that this decrease did not result from neuronal loss but rather from a reduction in the hybridization signals for rMrgC over small-to-medium diameter L5 and L6 dorsal root ganglia neurons. While the functional implications of the altered regulation of rMrgA and rMrgC in neuropathic pain models remain unclear, the results suggest that therapeutics targeting these receptors may have limited utility.