title: Serotonin and substance P afferents to parafascicular and central medial nuclei.
abstract: Potent analgesia is elicited by electrical stimulation of the periaqueductal gray (PAG), dorsal raphe nucleus (DRN) and intralaminar thalamus. Horseradish peroxidase conjugated wheat germ agglutinin (HRP-WGA) was stereotaxically pressure injected into the parafascicular (PF) or central medial (CM) nucleus to identify brainstem afferents to the intralaminar thalamus. WGA-immunoreactive (-ir) neurons were identified in the DRN, PAG and lateral dorsal tegmentum (LDTg) after PF and CM injections. Many retrogradely labeled cells in the DRN and ventral PAG were also serotonin-ir, and a portion of WGA-ir cells in the LDTg were substance P-ir. These results substantiate previous studies implicating the intralaminar thalamus and periaqueductal region, as well as serotonin and substance P, in antinociception.
authors.affiliation: Neuroendocrine Unit, University of Rochester School of Medicine, NY 14642.
authors.forename: L J
authors.initials: LJ
authors.lastname: Sim
authors.forename: S A
authors.initials: SA
authors.lastname: Joseph
mesh_terms: D000818:Animals; D006651:Histocytochemistry; D008297:Male; D009475:Neurons, Afferent / Q000737:chemistry* / Q000166:cytology; D010146:Pain / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D011975:Receptors, Mitogen / Q000302:isolation & purification; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000302:isolation & purification*; D011985:Receptors, Serotonin / Q000302:isolation & purification*; D013787:Thalamic Nuclei / Q000033:anatomy & histology*; D014909:Wheat Germ Agglutinins / Q000378:metabolism
chemical_list: D011975:Receptors, Mitogen; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D011985:Receptors, Serotonin; D014909:Wheat Germ Agglutinins; C027503:wheat germ agglutinin receptor