title: The neurosteroid pregnenolone sulfate reduces learning deficits induced by scopolamine and has promnestic effects in mice performing an appetitive learning task.
abstract: The effects of the neurosteroid pregnenolone sulfate (PS) on learning as well as on scopolamine-induced learning deficits were studied in Swiss mice using an appetitively reinforced Go-No Go visual discrimination task. Subcutaneous (SC) administration of scopolamine (0.3-3 mg/kg) after the first session of training dose-dependently impairs learning during the following sessions in this task. Moreover, intracerebroventricular (ICV) administration of PS (0.01-10 nmol) dose-dependently blocks learning deficits induced by scopolamine (3 mg/kg), with the most potent effects at the dose of 0.5 nmol PS. In addition to antagonizing the amnestic effects of scopolamine, PS (0.5 nmol ICV) has a memory-enhancing effect, when administered alone after the first training session. Scopolamine (3 mg/kg SC) also produced substantial deficits on retrieval performance in the Go-No Go visual discrimination task, and caused motor disturbances, when administered 15 min before testing. PS (0.5 nmol ICV) also reduced scopolamine-induced deficits on retrieval but had no effect on scopolamine-induced motor impairments in the traction reflex test. Such a rapid effect of PS on memory processes may be mediated via NMDA and/or GABAA receptors.
authors.affiliation: Laboratoire de Psychophysiologie, ULP, URA-CNRS 1295, Strasbourg, France.
authors.forename: H
authors.initials: H
authors.lastname: Meziane
authors.forename: C
authors.initials: C
authors.lastname: Mathis
authors.forename: S M
authors.initials: SM
authors.lastname: Paul
authors.forename: A
authors.initials: A
authors.lastname: Ungerer
mesh_terms: D000818:Animals; D004192:Discrimination, Psychological / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D007276:Injections, Intraventricular; D007858:Learning / Q000187:drug effects*; D008297:Male; D008568:Memory / Q000187:drug effects; D051379:Mice; D011284:Pregnenolone / Q000494:pharmacology*; D012601:Scopolamine / Q000037:antagonists & inhibitors / Q000494:pharmacology*
chemical_list: C018370:pregnenolone sulfate; D011284:Pregnenolone; D012601:Scopolamine