Stimulation of the medial forebrain bundle: behavioral dissociation of its rewarding and activating effects

Non-contingent electrical stimulation of the medial forebrain bundle with low current intensities which did not support self-stimulation behavior produced drastic motor activation and sniffing. In addition, self-stimulation was triggered only if current intensities were strong enough to produce aversion when forced-delivered. These results suggest that stimulation of the medial forebrain bundle involves both drive activating and rewarding components and that a sufficient activation of the first component is essential for the maintenance of self-stimulation behavior.