Stimulation of ventral tegmental area and nucleus accumbens reduce receptive fields for hypothalamic biting reflex in cats

Abstract

Stimulation of the ventral tegmental area (VTA) and nucleus accumbens (NA) suppressed attack behavior elicited by hypothalamic stimulation. Because the nondirected somatic motor and autonomic components of attack were not affected by VTA or NA stimulation, and previous work had demonstrated the importance of sensory guidance in attack, the mechanism for suppression was postulated to be on the sensory component of the attack reaction. We investigated the effects of VTA and NA stimulation on the biting reflex, one of the sensory-controlled components of hypothalamically elicited attack behavior. The receptive field for biting was measured during hypothalamic stimulation with and without concurrent VTA and NA stimulation. At stimulation parameters that inhibited attack, the extent of the receptive field was reduced. Thus, VTA and NA may produce inhibition of attack by acting on the sensory component of the response mechanism. We suggest that reduction of receptive fields is a mechanism by which behavioral inhibition is mediated in the central nervous system.