Dopamine D1 receptor signalling in the lateral shell of the nucleus accumbens controls dietary fat intake in male rats

Abstract

Central dopamine signaling regulates reward-related aspects of feeding behavior, and during diet-induced obesity dopamine receptor signaling is altered. Yet, the influence of dopamine signaling on the consumption of specific dietary components remains to be elucidated. We have previously shown that 6-hydroxydopamine-mediated lesions of dopamine neuron terminals in the lateral shell of the nucleus accumbens promotes fat intake in rats fed a multi-component free-choice high-fat high-sugar (fcHFHS) diet. It is however not yet determined which dopamine receptors are responsible for this shift towards fat preference. In this study, we assess the effects of D1-or D2 receptor acute inhibition in the lateral shell of the nucleus accumbens on fcHFHS diet consumption. We report that infusion of the D1 receptor antagonist SCH2 3390, but not the D2 receptor antagonist raclopride, promotes dietary fat consumption in male Sprague Dawley rats on a fcHFHS diet during 2 h after infusion. Furthermore, anatomical analysis of infusion sites revealed that the rostral region, but not the caudal region, of the lateral shell of the nucleus accumbens is sensitive to the D1 receptor inhibition effects on fat consumption. Our data highlight a role for D1 receptors in the rostral region of the lateral shell of the nucleus accumbens to control dietary fat consumption.

Keywords: Dopamine receptors; Fat and sugar intake; Nucleus accumbens; Obesogenic diet; Rat.