Blockade of hippocampal nicotinic receptors impairs working memory but not reference memory in rats.
In a three-panel runway task, intrahippocampal injection of the nicotinic receptor antagonist, mecamylamine (10 and 18 micrograms/side), significantly increased the number of errors (attempts to pass through two incorrect panels of the three panel-gates at four choice points) in a test of working memory. This increase in errors also occurred after rats were given IP mecamylamine (10 mg/kg). Mecamylamine did not affect the number of errors in a test of reference memory whether it was given at doses up to 18 micrograms/side intrahippocampally or up to 10 mg/kg IP. These results suggest that mechanisms mediated by hippocampal nicotinic receptors play a role in working memory but not in reference memory.
Ohno
M
M
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
Yamamoto
T
T
Watanabe
S
S
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D007267:Injections; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D008568:Memory / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000187:drug effects*
D011978:Receptors, Nicotinic; D008464:Mecamylamine