The aim of the study was to reveal the changes of Fos-immunoreactivity in zones of localization of catecholaminergic (CA) groups of brainstem cells in rats realized food-procuring movements in the cases of normal functioning and during inhibition of neuronal nitric oxide synthase (nNOS) system using a selective blocker 7-Nitroindazole (7-NI). A marked increase of c-Fos expression was registered mostly in the neurons of A1, A5, A6, and A7 groups during the performance of operant movements. In the А5, А6 and A7 CA groups, we observed a maximum number of Fos-ir neurons, as compared with the control values, with contralateral predominance of Fos-immunoreactivity. It is supposed that the activation of the brainstem CA neurons during realization of motor program may be associated with an increase of inhibitory sympathoadrenal influences on muscle spindles and proprioceptors and the changes of the peripheral vascular tone. This shows the direct influence of the autonomic nervous system in modulation of motor acts during realization of operant movements in animals. The preliminary injection of a selective blocker of nNOS 7-NI to the rats, that realized food-procuring movements, resulted in the further increase of Fos-immunoreactivity in the neurons of the above-mentioned CA groups. The highest number of Fos-ir-cells was registered in A5 with marked contralateral predominance of Fos-immunoreactivity. A similar trend in the A6 and A7 cell groups was observed. Thus, it has been revealed that the modulation of the level of nitric oxide production can affect on the activity of neuronal networks of the brainstem and spinal cord, which directly involved in the regulation of motor acts.