title: Lateral hypothalamus: site involved in pain modulation.
abstract: The present study is an attempt to examine the neuronal circuitry of a supraspinal site engaged in pain modulation. Five physiological measures were postulated as the criteria for defining a central nervous system site engaged in the circuitry of pain modulation. The lateral hypothalamus met these five measures: (i) 81% of the lateral hypothalamus neurons (247/304) responded to noxious stimuli using a single cell recording procedure; (ii) stimulation of the periaqueductal gray-dorsal raphe area or the habenula modulated 98% and 87% of the lateral hypothalamus noxious-evoked activity; (iii) microiontophoretically applied morphine modulated 77% of the lateral hypothalamus noxious evoked activity; (iv) electrical stimulation of the lateral hypothalamus produced behavioral analgesia proportional to the stimulus intensity as assessed by the tail flick assay; and (v) morphine application into the lateral hypothalamus produced behavioral analgesia in a dose-response manner using the tail flick assay. In conclusion, the lateral hypothalamus can be considered one of the pain modulation sites.
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Medical School, Houston, TX 77225, USA.
authors.forename: N
authors.initials: N
authors.lastname: Dafny
authors.forename: W Q
authors.initials: WQ
authors.lastname: Dong
authors.forename: C
authors.initials: C
authors.lastname: Prieto-Gomez
authors.forename: C
authors.initials: C
authors.lastname: Reyes-Vazquez
authors.forename: J
authors.initials: J
authors.lastname: Stanford
authors.forename: J T
authors.initials: JT
authors.lastname: Qiao
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D009020:Morphine / Q000627:therapeutic use; D010146:Pain / Q000188:drug therapy / Q000503:physiopathology*; D010147:Pain Measurement; D051381:Rats; D011930:Reaction Time / Q000502:physiology
chemical_list: D009020:Morphine