The 5-HT1A receptor and recognition memory. Possible modulation of its behavioral effects by the nitrergic system.
Functional activation of the 5-HT1A receptor inhibits cognition, although discrepant findings have also been reported. The present study was designed to investigate the role of the 5-HT1A receptor on recognition memory in the rat. For this purpose, the effects induced by the 5-HT1A agonist R-(+)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT) and the 5-HT1A antagonist WAY 100635 on memory were evaluated by using the object recognition task. In addition, the possible involvement of the nitrergic system on 5-HT1A receptor's effects was also assessed by using the same behavioral procedure. In the first dose-response study, post-training administration of 8-OH-DPAT (0.1 and 0.3 mg/kg, subcutaneously (s.c.)) dose-dependently impaired animals' performance in this test. WAY 100635 (0.3 and 1 mg/kg, intraperitoneally (i.p.)) successfully antagonized these 8-OH-DPAT-induced performance deficits. The NO donor molsidomine (2 and 4 mg/kg, i.p.) counteracted cognition deficits produced by the highest dose of 8-OH-DPAT (0.3 mg/kg). Our findings indicate (a) that the 5-HT1A receptor is involved in recognition memory, and (b) that a NO component modulates the effects of the 5-HT1A receptor on learning and memory.
Pitsikas
Nikolaos
N
Department of Pharmacology, School of Medicine, University of Thessaly, 22 Papakiriazi Str., 412-22 Larissa, Greece. npitsikas@med.uth.gr
Tsitsirigou
Stavroula
S
Zisopoulou
Styliani
S
Sakellaridis
Nikolaos
N
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D008981:Molsidomine / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects / Q000502:physiology*; D021641:Recognition, Psychology / Q000187:drug effects / Q000502:physiology*; D018490:Serotonin Agents / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D020030:Nitric Oxide Donors; D010879:Piperazines; D011725:Pyridines; D018490:Serotonin Agents; D044282:Receptor, Serotonin, 5-HT1A; D009569:Nitric Oxide; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D008981:Molsidomine