title: Sex differences in cocaine-stimulated motor behavior: disparate effects of gonadectomy.
abstract: Sex differences in biological substrates of drug use and addiction are poorly understood. The present study investigated sexual dimorphisms in motor behavior following acute cocaine administration (10, 20, or 40 mg/kg, i.p.). Cocaine increased stereotypy rating, horizontal and vertical activity in both sexes, and effects were always greater in females than males. A population analysis using data from multiple experiments indicated that horizontal activity scores were normally distributed in males but not in females. Gonadectomy induced disparate effects on cocaine-stimulated motor behavior. Population analysis indicated that castrated males exhibited more horizontal activity and stereotypy than shams. Ovariectomy did not affect cocaine-stimulated stereotypy but did attenuate horizontal activity in a subset of rats that had not been vaginally lavaged. In summary, gonadectomy effects were sex and behavioral topography specific and indicate that activational effects of gonadal hormones partially mediate the robust sex differences in cocaine-stimulated open-field behavior.
authors.affiliation: Department of Pharmacology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Q D
authors.initials: QD
authors.lastname: Walker
authors.forename: J
authors.initials: J
authors.lastname: Cabassa
authors.forename: K A
authors.initials: KA
authors.lastname: Kaplan
authors.forename: S T
authors.initials: ST
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Haroon
authors.forename: H A
authors.initials: HA
authors.lastname: Spohr
authors.forename: C M
authors.initials: CM
authors.lastname: Kuhn
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D003627:Data Interpretation, Statistical; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D009919:Orchiectomy / Q000009:adverse effects; D010052:Ovariectomy / Q000009:adverse effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013239:Stereotyped Behavior / Q000187:drug effects / Q000502:physiology; D013256:Steroids / Q000378:metabolism
chemical_list: D018765:Dopamine Uptake Inhibitors; D012739:Gonadal Steroid Hormones; D013256:Steroids; D003042:Cocaine