Effects of nicotine and mecamylamine on cognition in rhesus monkeys.
BACKGROUND
Nicotine and other agonists of nicotinic cholinergic receptors (nAChR) have been shown to improve performance in specific memory domains in rodents and monkeys. Such beneficial effects are observed in preclinical models of age-related cognitive decline, stimulating interest in nAChR ligands as possible therapeutics. Prior work has typically focused on assays of spatial working memory in rodent studies and visual recognition memory in monkey studies.


OBJECTIVE
The current study was conducted to determine the role played by nAChRs in multiple types of memory in monkeys.


METHODS
Rhesus monkeys (n=6) were trained to perform a battery of six behavioral tasks and then serially challenged with acute doses of nicotine (3.2-56 microg/kg, i.m.) and the nAChR antagonist mecamylamine (0.32-1.78 mg/kg, i.m.).


RESULTS
Nicotine improved performance on tests designed to assay visual recognition memory, spatial working memory and visuo-spatial associative memory, while mecamylamine impaired visuo-spatial associative memory. Ballistic and fine motor performance was not significantly improved by nicotine but fine motor performance was impaired by mecamylamine.


CONCLUSIONS
Although nicotine may improve performance in multiple domains, effects on visuo-spatial associative memory is the most specifically attributable to nAChR signaling.
Katner
Simon N
SN
Department of Neuropharmacology, CVN-7, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Davis
Sophia A
SA
Kirsten
Amber J
AJ
Taffe
Michael A
MA
D000818:Animals; D003071:Cognition / Q000187:drug effects*; D007858:Learning / Q000187:drug effects; D008253:Macaca mulatta; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology*; D008568:Memory / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects
D018722:Nicotinic Agonists; D008464:Mecamylamine; D009538:Nicotine