Effects of nicotine on memory impairment induced by blockade of muscarinic, nicotinic and dopamine D2 receptors in rats.
Scopolamine dose-dependently inhibits passive avoidance latency and decreases spontaneous alternation in the Y-maze, suggesting effects on long-term and short-term memory, respectively. Chlorisondamine (10 mg/kg), a compound which produces a long-lasting central nicotinic receptor blockade, did not affect short-term and long-term memory performance. In normal rats, nicotine at the doses of 0.3, 1.0, and 3.0 mg/kg administered once had a facilitating effect on short-term memory; a higher dose (3.0 mg/kg) did not show a more pronounced effect than a lower one (0.3 mg/kg). Nicotine, by activating the nicotinic acetylcholine receptors, attenuated the impairment of short-term memory induced by muscarinic or dopamine D2 receptor blockade. On long-term memory, a single dose of nicotine (0.3, 1.0, 3.0 mg/kg) did not affect memory performance, but improved it after chronic (10 consecutive days, 0.3 mg/kg) administration. The antiamnesic effect of nicotine administered once was observed in scopolamine-, scopolamine+chlorisondamine- or sulpiride-treated rats. These results suggest that the antiamnesic effect of nicotine can result from an action at nicotinic receptors subtypes not blocked by chlorisondamine or at nonnicotinic receptors.
Hefco
Vasile
V
Department of Physiology, "Al.I.Cuza" University, 6600 Iasi, Romania. vhefco@uaic.ro
Yamada
Kiyofumi
K
Hefco
Andreea
A
Hritcu
Lucian
L
Tiron
Adrian
A
Olariu
Ana
A
Nabeshima
Toshitaka
T
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D002714:Chlorisondamine / Q000494:pharmacology; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology / Q000627:therapeutic use*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000502:physiology; D011976:Receptors, Muscarinic / Q000502:physiology*; D011978:Receptors, Nicotinic / Q000502:physiology*; D012601:Scopolamine / Q000494:pharmacology
D065127:Dopamine D2 Receptor Antagonists; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D017448:Receptors, Dopamine D2; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D009538:Nicotine; D012601:Scopolamine; D002714:Chlorisondamine