Physiol. Res. 49: 143-149, 2000


Inhibition of NO Synthase Activity in Nervous Tissue Leads to Decreased Motor Activity in the Rat

L. Halčák, 1O. Pecháňová, Z. Žigová, 1L. Klemová, 2M. Novacký, 1I. Bernátová

Department of Medical Chemistry, Biochemistry and Clinical Biochemistry, Medical Faculty, Comenius University, 1Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, 2Department of Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic

Received July 30, 1999
Accepted September 21, 1999


Summary
The nitric oxide/cGMP system has been shown to play a crucial role in the mechanism of learning and memory. The aim of the present study was to investigate whether the inhibition of NO synthase in brain regions leads to alterations of spontaneous behavior in rats. Male Wistar rats were treated with NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) at the dose of 40 mg/kg/day. After 4 weeks of L-NAME treatment, NO synthase activity was significantly decreased by 75 % in the cerebellum, by 71 % in the cerebral cortex and by 72 % in the thoracic spinal cord. Decreased NO synthase activity in the nervous tissue was associated with decreased motor horizontal and vertical activities as well as by lowered frequency of sniffing, cleaning and defecation. It is concluded that the inhibition of NO synthase activity has a suppressive effect on spontaneous behavior of rats.


Key words
Nitric oxide · L-NAME · Nervous tissue · Spontaneous behavior · Habituation tasks

Reprint requests
Doc. Ing. Lukáč Halčák, Ph.D., Department of Medical Chemistry, Biochemistry and Clinical Biochemistry, Medical Faculty, Comenius University, 813 71 Bratislava, Slovak Republic.


© 2000 by the Institute of Physiology, Czech Academy of Sciences