title: ERK1/2 Phosphorylation in the Rat Supraoptic Nucleus, Dorsal Raphe Nucleus, and Locus Coeruleus Neurons Following Noxious Stimulation to the Hind Paw.
abstract: Phospho-ERK1/2 (pERK1/2) fluorescence-immunohistochemistry is specifically well suited to mirror neuronal activity in the pain pathway at the cellular level. This study employed this method to visualize neuronal activity in 3 rat CNS nuclei following an acute noxious stimulation. The rat hind paw was stimulated either by heat or by a sequence of mustard oil and heat. Two min after the thermal stimulation or after the combined mustard oil and thermal stimulation, there was a significant increase in cells showing pERK1/2 immunoreactivity in the supraoptic nucleus (SON), in the dorsal raphe nucleus (DRN), and in the locus coeruleus (LC). Pretreatment with the opioid analgesic morphine or the N-methyl-D-aspartate antagonist MK-801 markedly attenuated ERK1/2 phosphorylation. These findings support the concept that the SON, the DRN, and the LC are integrated into pain processing at the hypothalamic and brain stem level.
authors.affiliation: Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria.
authors.forename: Josef
authors.initials: J
authors.lastname: Donnerer
authors.forename: Ingrid
authors.initials: I
authors.lastname: Liebmann
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000503:physiopathology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D065847:Dorsal Raphe Nucleus / Q000503:physiopathology; D006358:Hot Temperature; D007150:Immunohistochemistry; D008125:Locus Coeruleus / Q000503:physiopathology; D010146:Pain / Q000503:physiopathology*; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013495:Supraoptic Nucleus / Q000503:physiopathology
chemical_list: D000701:Analgesics, Opioid; D016291:Dizocilpine Maleate