Effects of L-Arginine on 7-Nitroindazole-Induced Reference and Working Memory Performance of Rats

• Published in: Pharmacology Vol. 84; no. 4; pp. 211 - 218
• Main Authors: Akar, Füruzan Yildiz, Celikyurt, Ipek Komsuoglu, Ulak, Guner, Mutlu, Oguz
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.01.2009
• Subjects: Animals; Arginine - pharmacology; Dose-Response Relationship, Drug; Drug Interactions; Enzyme Inhibitors - pharmacology; Indazoles - antagonists & inhibitors; Indazoles - pharmacology; Male; Memory - drug effects; Original Paper; Rats; Rats, Wistar; Reference memory; 7-Nitroindazole; Working memory; Nitric oxide; Three-panel runway test
• ISSN: 0031-7012; 1423-0313
• DOI: 10.1159/000235997

Background/Aims: This study was performed in order to elucidate the effects of 7-nitroindazole (7-NI) and L-arginine on cognitive functions of rats in a three-panel runway task. Methods: 7-NI (2.5, 5, 10 mg/kg) and L-arginine (200 mg/kg) were injected intraperitoneally into male Wistar rats 30 min before the test. Results: 7-NI (5, 10 mg/kg) significantly increased the number of errors (pushes made on the 2 incorrect panels of the panel gate at 4 choice points) and prolonged the latency of reference memory in the three-panel runway task. The negative effects of 7-NI on reference memory was counteracted by L-arginine, a substrate for nitric oxide synthase. While having no effect on the number of working memory errors in working memory trials, 7-NI prolonged the latency from the 2nd to the 6th trial at the 5- and 10-mg/kg doses. Concurrent administration with L-arginine counteracted the 7-NI-induced prolongation of latency from the 2nd to the 6th trial. Conclusion: 7-NI impaired reference memory but not working memory in the three-panel runway test. Moreover, nitric oxide played an essential role in the development of reference memory and the negative effects of 7-NI on memory were counteracted by L-arginine.