Effects of histamine and cholinergic systems on memory retention of passive avoidance learning in rats.
In the present study, the effects of the histamine and cholinergic systems on memory retention in adult male rats were investigated. Post-training intracerebroventricular injections were carried out in all the experiments. Cholinoceptor agonist, acetylcholine (1-10 microg/rat) or nicotine (1-10 microg/rat), increased, while a cholinoceptor antagonist, scopolamine (5-20 microg/rat), decreased memory retention. The response to acetylcholine was attenuated by scopolamine. Administration of histamine (5-20 microg/rat) reduced, but the histamine H(1) receptor antagonist, pyrilamine (10-50 microg/rat), and the histamine H(2) receptor antagonist, cimetidine (1-50 microg/rat), increased memory retention in rats. The histamine receptor antagonists attenuated the response to histamine. Histamine reduced the acetylcholine- or nicotine-induced enhancement. The histamine receptor antagonists enhanced the nicotine- or acetylcholine-induced response. Histamine potentiated the inhibitory effect induced by scopolamine. It is concluded that histaminergic and cholinergic systems have opposing effects on memory retention. Also, the histaminergic system elicits an interaction with the cholinergic system in memory retention.
Eidi
Maryam
M
Department of Biology, Sciences and Research Campus, Azad University, Tehran, Iran.
Zarrindast
Mohammad-Reza
MR
Eidi
Akram
A
Oryan
Shahrbanoo
S
Parivar
Kazem
K
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D002927:Cimetidine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time; D011950:Receptors, Cholinergic / Q000502:physiology*; D011968:Receptors, Histamine / Q000502:physiology*; D012153:Retention, Psychology / Q000187:drug effects; D012601:Scopolamine / Q000494:pharmacology
D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D018727:Muscarinic Antagonists; D011950:Receptors, Cholinergic; D011968:Receptors, Histamine; D009538:Nicotine; D002927:Cimetidine; D012601:Scopolamine; D011738:Pyrilamine; D000109:Acetylcholine