title: Duration and frequency of multiunit electrical activity associated with the hypothalamic gonadotropin releasing hormone pulse generator in the rhesus monkey: differential effects of morphine.
abstract: The effects of morphine on the frequency and duration of the characteristic bursts or 'volleys' of multiunit electrical activity (MUA) associated with pulsatile pituitary luteinizing hormone (LH) secretion were studied in unanesthetized ovariectomized rhesus monkeys bearing bilateral arrays of electrodes implanted in the mediobasal hypothalamus. Morphine administration resulted in a dose-dependent decrease in MUA volley duration and frequency. When morphine was infused at 10 micrograms/kg/h, the inhibiting effect on volley duration was observed without a change in volley frequency. It is concluded that the frequency and duration of hypothalamic MUA volleys associated with pulsatile LH secretion may be independently regulated.
authors.affiliation: Laboratory for Neuroendocrinology, University of Texas Medical School, Houston.
authors.forename: C L
authors.initials: CL
authors.lastname: Williams
authors.forename: M
authors.initials: M
authors.lastname: Nishihara
authors.forename: J C
authors.initials: JC
authors.lastname: Thalabard
authors.forename: K T
authors.initials: KT
authors.lastname: O'Byrne
authors.forename: P M
authors.initials: PM
authors.lastname: Grosser
authors.forename: J
authors.initials: J
authors.lastname: Hotchkiss
authors.forename: E
authors.initials: E
authors.lastname: Knobil
mesh_terms: D000818:Animals; D004594:Electrophysiology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000502:physiology*; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology*; D007986:Luteinizing Hormone / Q000378:metabolism; D008253:Macaca mulatta; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D010052:Ovariectomy
chemical_list: D007987:Gonadotropin-Releasing Hormone; D009270:Naloxone; D009020:Morphine; D007986:Luteinizing Hormone