Get your full text copy in PDF
Furuzan Akar, Oguz Mutlu, Ipek Komsuoglu Celikyurt, Emine Bektas, Pelin Tanyeri, Guner Ulak, Faruk Erden
(Department of Pharmacology, Kocaeli University, Medical Faculty, Kocaeli, Turkey)
Med Sci Monit Basic Res 2014; 20:27-35
Nitric oxide (NO) is an intercellular messenger that plays a critical role in learning and memory processes. Effects of nitric oxide synthase (NOS) inhibitors and guanylate cyclase (GC) inhibitors on cognitive function remain controversial.
Material and Methods: The aim of this study was to investigate effects of an NOS inhibitor, 7-nitroindazole (7-NI), and a GC inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), on different aspects of memory in passive avoidance (PA), novel object recognition (NOR), and social transmission of food preference (STFP) tests. Male Balb-c mice were treated intraperitoneally with 7-NI (15 mg/kg), ODQ (3,10 mg/kg), L-arginine (100 mg/kg) + 7-NI (15 mg/kg), or physiological saline.
Results: ODQ (10 mg/kg) and 7-NI (15 mg/kg) significantly decreased second-day latency in PA test. 7-NI (15 mg/kg) and ODQ (10 mg/kg) significantly decreased the ratio index in the NOR test. 7-NI and ODQ (10 mg/kg) decreased cued/non-cued food eaten in STFP test. Amount of time spent in center zone significantly increased in ODQ (10 mg/kg) and 7-NI (15 mg/kg) groups in open field test, but there was no effect on total distance moved and speed of animals. ODQ (10 mg/kg) significantly increased number of entries into new compartments in exploratory activity apparatus, while 7-NI had no effect. Administration of L-arginine (100 mg/kg) before 7-NI reversed 7-NI-induced effects, supporting the role of NO in cognition.
Conclusions: Our results confirm that inhibition of NO/cGMP/GS pathway might disturb emotional, visual, and olfactory memory in mice. Also, 7-NI and ODQ had anxiolytic effects in open field test, and ODQ also enhanced exploratory activity.
Keywords: Anxiety - physiopathology, Animals, Arginine - pharmacology, Avoidance Learning - drug effects, Exploratory Behavior - drug effects, Food Preferences - drug effects, Indazoles - pharmacology, Memory - drug effects, Mice, Mice, Inbred BALB C, Motor Activity - drug effects, Oxadiazoles - pharmacology, Quinoxalines - pharmacology, Smell - drug effects, Social Behavior