title: Rat hypothalamic arcuate neuron response in electroacupuncture-induced analgesia.
abstract: Electroacupuncture (EA) effects on activity of arcuate neurons of the hypothalamus (ARH) and on magnitude of the digastric electromyogram (dEMG) in the jaw opening reflex were investigated, in both p-chlorophenylalanine pretreated and normal Wistar rats. EA stimulation (300-500 microA, 5 msec pulses, for 15 min) was delivered unilaterally to a meridian Ho-Ku point of anesthetized rats at 3, 45 and 100 Hz. In control animals, EA stimulation at 3, 45 or 100 Hz induced long-lasting suppression of the magnitude of the dEMG activity and changed the spontaneous firing rate of most of the ARH neurons: the rate either increased (type I) or decreased (type II). After low-frequency stimulation, there were significantly more type I neurons than type II; after high-frequency stimulation, there were significantly more type II neurons than type I. In serotonin-depleted rats, however, high-frequency stimulation suppressed dEMG activity only slightly and induced a smaller proportion of type II neurons.
authors.affiliation: Department of Physiology, School of Dentistry, Showa University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hamba
authors.forename: K
authors.initials: K
authors.lastname: Toda
mesh_terms: D015670:Acupuncture Therapy; D000698:Analgesia; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D010134:Fenclonine / Q000494:pharmacology; D007568:Jaw / Q000294:innervation; D008473:Median Eminence / Q000502:physiology; D008839:Microelectrodes; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012018:Reflex
chemical_list: D010134:Fenclonine