The effect of a selective neuronal nitric oxide synthase inhibitor 3-bromo 7-nitroindazole on spatial learning and memory in rats

• Published in: Pharmacology, biochemistry and behavior Vol. 131; pp. 19 - 25
• Main Authors: Gocmez, Semil Selcen, Yazir, Yusufhan, Sahin, Deniz, Karadenizli, Sabriye, Utkan, Tijen
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2015
• Subjects: 3-Br 7-NI; Animals; Arginine - pharmacology; Brain-Derived Neurotrophic Factor - analysis; Brain-Derived Neurotrophic Factor - biosynthesis; Hippocampus - chemistry; Hippocampus - drug effects; Indazoles - antagonists & inhibitors; Indazoles - pharmacology; Male; Memory - drug effects; Morris water maze; Nitric oxide; Nitric Oxide Synthase Type I - antagonists & inhibitors; Rats; Rats, Wistar; Spatial Learning - drug effects; Spatial memory; 3-Br 7-NI; Morris water maze; Nitric oxide; Spatial memory
• DOI: 10.1016/j.pbb.2015.01.013
• ISSN: 0091-3057; 1873-5177

Since the discovery of nitric oxide (NO) as a neuronal messenger, its way to modulate learning and memory functions is subject of intense research. NO is an intercellular messenger in the central nervous system and is formed on demand through the conversion of L-arginine to L-citrulline via the enzyme nitric oxide synthase (NOS). Neuronal form of nitric oxide synthase may play an important role in a wide range of physiological and pathological conditions. Therefore the aim of this study was to investigate the effects of chronic 3-bromo 7-nitroindazole (3-Br 7-NI), specific neuronal nitric oxide synthase (nNOS) inhibitor, administration on spatial learning and memory performance in rats using the Morris water maze (MWM) paradigm. Male rats received either 3-Br 7-NI (20mg/kg/day) or saline via intraperitoneal injection for 5days. Daily administration of the specific neuronal nitric oxide synthase (nNOS) inhibitor, 3-Br 7-NI impaired the acquisition of the MWM task. 3-Br 7-NI also impaired the probe trial. The MWM training was associated with a significant increase in the brain-derived neurotrophic factor (BDNF) mRNA expression in the hippocampus. BDNF mRNA expression in the hippocampus did not change after 3-Br 7-NI treatment. L-arginine significantly reversed behavioural parameters, and the effect of 3-Br 7-NI was found to be NO-dependent. There were no differences in locomotor activity and blood pressure in 3-Br 7-NI treated rats. Our results may suggest that nNOS plays a key role in spatial memory formation in rats. •3-Br 7-NI impaired spatial learning and memory in rats.•BDNF expression in the hippocampus was increased after MWM training.•3-Br 7-NI did not affect the BDNF expression in the hippocampus.•L-arginine significantly reversed behavioural parameters of 3-Br 7-NI treatment.•It may be suggested that nNOS plays the key role on spatial memory formation in rats.