ISSN:
1432-2072
Keywords:
(−)-Nicotine
;
(+)-Nicotine
;
Cholinergic neuronal system
;
Carbon monoxide
;
Delayed amnesia
;
Learning
;
Mecamylamine
;
Passive avoidance
;
Stereoisomer
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The effects of nicotine on carbon monoxide (CO)-induced amnesia in mice were investigated using a step-down type passive avoidance task. Mice were exposed to CO 3 times at 1-h intervals, 7 days before the first training and retention test and 24 h after the first training session. Memory deficiency occurred in mice when training commenced more than 3 days after CO exposure (delayed amnesia): the median step-down latency in the retention test of the CO-exposed group was significantly shorter than that of the control group. Administration of (−)-nicotine (15.6 and 31.3 nmol/kg, IP) 15 min before the first training session prolonged the step-down latency in the CO-exposed group, but (+)-nicotine did not. To determine whether this effect of (−)-nicotine was mediated via nicotinic cholinergic receptors, we attempted to block its action using a nicotinic acetylcholine receptor antagonist (mecamylamine). Mecamylamine (1.25 µmol/kg) blocked the effect of (−)-nicotine (31.3 nmol/kg) on delayed amnesia. Administration of (−)-nicotine (15.6–62.5 nmol/kg) immediately after the first training session failed to ameliorate learning ability in the CO-exposed group. These results suggest that (−)-nicotine potentiates the nicotinic cholinergic neuronal system and may potentiate acquisition of memory.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02244868
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