Effects of nicotine on memory retrieval in mice.
The effect of nicotine was tested on retrieval 24 h after training on a passive avoidance task. Intraperitoneal (i.p.) injection of nicotine (0.25-1.5 mg/kg) increased the step-down latency in mice dose dependently. Pretreatment with the nicotinic receptor antagonist mecamylamine (0.5-1 mg/kg) decreased, whereas pretreatment with the dopamine D1 receptor antagonist SCH 23390 (R-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-ol maleate) (0.01, 0.05 and 0.1 mg/kg) and the beta-adrenoreceptor antagonist propranolol (10 mg/kg) increased the nicotine response. The dopamine receptor D2 receptor antagonist sulpiride (5-10 mg/kg), the anti-muscarinic agent atropine (2.5-10 mg/kg), the peripheral nicotinic receptor antagonist hexamethonium (0.01-0.5 mg/kg), the alpha-adrenoceptor antagonist phenoxybenzamine (1 and 10 mg/kg) and the peripheral dopamine D2 receptor antagonist domperidone (5 and 10 mg/kg) did not change the response induced by nicotine. Single administration of the antagonists did not cause response; however, a high dose of domperidone (10 mg/kg) and propranolol alone increased the step-down latencies. It may be concluded that a nicotinic receptor mechanism is involved in the nicotine-induced improvement of memory retrieval.
Zarrindast
M R
MR
Department of Pharmacology, Tehran University of Medical Sciences, Iran.
Sadegh
M
M
Shafaghi
B
B
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001552:Benzazepines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D008815:Mice, Inbred Strains; D009538:Nicotine / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D011930:Reaction Time / Q000187:drug effects
D001552:Benzazepines; D009538:Nicotine; D011433:Propranolol