title: Muscimol microinjected in the arcuate nucleus affects metabolism, body temperature & ventilation.
abstract: Effects of microinjection of 2 doses of γ-aminobutyric acid (GABA)A receptor agonist, muscimol (M), into the hypothalamic arcuate nucleus on oxygen consumption and control of ventilation over time and body temperature (BT) at the end of the experiment were compared in adult male and female rats. Relative to cerebrospinal fluid (CSF, 0 nmol), BT was decreased only in male rats with both doses of M, while in female rats, the 5 nmol dose depressed oxygen consumption. Ventilation was depressed by 5 nmol M in male and 10 nmol M in female rats by decreasing tidal volume. M did not affect the ventilatory response of male or female rats to hypoxia, whereas in females 5 and 10 nmol M and in males 10 nmol M depressed the ventilatory response to hypercapnia. Thus, in rats GABAA receptors in the arcuate nucleus modulate BT, oxygen consumption, and ventilation in air and in response to hypercapnia in a sexually dimorphic manner.
authors.affiliation: Division of Basic Biomedical Sciences, Sanford School of Medicine at University of South Dakota, Vermillion, SD 57069, United States. Electronic address: Evelyn.Schlenker@usd.edu.
authors.forename: Evelyn H
authors.initials: EH
authors.lastname: Schlenker
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects* / Q000502:physiology; D001831:Body Temperature / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D058785:GABA-A Receptor Agonists / Q000008:administration & dosage*; D000860:Hypoxia / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D008845:Microinjections; D009118:Muscimol / Q000008:administration & dosage*; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects*; D012727:Sex Characteristics; D013990:Tidal Volume / Q000187:drug effects / Q000502:physiology
chemical_list: D058785:GABA-A Receptor Agonists; D009118:Muscimol
keywords: Arcuate nucleus; Body temperature; GABA receptors; Oxygen consumption; Sexual dimorphism; Ventilation