title: Nicotine reverses adult-onset hypothyroidism-induced impairment of learning and memory: Behavioral and electrophysiological studies.
abstract: Nicotine alleviates cognitive impairment associated with a variety of health conditions. We examined the effect of chronic nicotine treatment on adult-onset hypothyroidism-induced impairment of learning and memory in rats. Hypothyroidism was induced by surgical removal of thyroid glands (thyroidectomy). One month later, chronic nicotine treatment (1 mg/kg sc, twice/day) was instituted for 4-6 weeks. Test of hippocampus-dependent spatial learning and memory in the radial arm water maze showed that hypothyroidism impaired learning as well as short-term and long-term memory retention. Chronic nicotine treatment reversed the hypothyroidism-induced learning and memory impairment. In normal rats, chronic nicotine treatment had no effect on learning and memory. Extracellular recordings from the CA1 region of anesthetized hypothyroid rats showed severe reduction of both early-phase and late-phase long-term potentiation (LTP) magnitude, which was reversed in nicotine-treated hypothyroid rats. These results show that chronic nicotine treatment prevents hypothyroidism-induced impairment of spatial cognition and LTP.
authors.affiliation: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas 77204-5515, USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Alzoubi
authors.forename: A M
authors.initials: AM
authors.lastname: Aleisa
authors.forename: N Z
authors.initials: NZ
authors.lastname: Gerges
authors.forename: K A
authors.initials: KA
authors.lastname: Alkadhi
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004195:Disease Models, Animal; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology / Q000528:radiation effects; D007037:Hypothyroidism / Q000150:complications* / Q000209:etiology; D007859:Learning Disabilities / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008569:Memory Disorders / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D009538:Nicotine / Q000627:therapeutic use*; D018722:Nicotinic Agonists / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D013037:Spatial Behavior / Q000187:drug effects; D013965:Thyroidectomy / Q000379:methods; D013997:Time Factors
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine