title: Behavioral and neuroanatomical sequelae of prenatal naloxone administration in the rat.
abstract: Pregnant Long-Evans hooded rats were dosed subcutaneously with 1 or 5 mg/kg/day naloxone hydrochloride, or an equal volume of vehicle, from gestational Day 4 (GD4) through GD19. Offspring were assessed for development of righting reflex, negative geotaxis, and open field activity, and for acquisition of a Warden maze; offspring sacrificed at postnatal Day (PND) 21 were assessed for several parameters of cerebellar, hippocampal, and motor cortical morphology. Five mg/kg/day naloxone accelerated development of negative geotaxis and righting reflex, while 1 mg/kg/day naloxone tended to slow development. Low dose females had significantly more errors than controls on the first day of maze learning. The high dose group had a significantly higher concentration of granule cells in the curvature of the dentate gyrus than controls; other neuroanatomical measures were unaffected by dosing. These findings confirm and extend previous work indicating that prenatal exposure to naloxone may alter neurobehavioral development in the rat.
authors.affiliation: Department of Psychology, George Mason University, Fairfax, VA 22030.
authors.forename: N A
authors.initials: NA
authors.lastname: Shepanek
authors.forename: R F
authors.initials: RF
authors.lastname: Smith
authors.forename: Z E
authors.initials: ZE
authors.lastname: Tyer
authors.forename: G D
authors.initials: GD
authors.lastname: Royall
authors.forename: K S
authors.initials: KS
authors.lastname: Allen
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000033:anatomy & histology / Q000187:drug effects*; D002531:Cerebellum / Q000187:drug effects; D005260:Female; D006624:Hippocampus / Q000187:drug effects; D007858:Learning / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009044:Motor Cortex / Q000187:drug effects; D009270:Naloxone / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D012018:Reflex / Q000187:drug effects
chemical_list: D009270:Naloxone