Repeated sucrose access influences dopamine D2 receptor density in the striatum

Abstract

A decrease in D2 dopamine receptor subtype (D2R) binding in the striatum has been reported in obese individuals and drug addicts. We examined D2R density in the striatum of food-restricted rats that had contingent access to food with different incentive values. Results showed that animals receiving limited access to 0.3 M sucrose paired 2 h with a chow meal for 7 days had a significantly lower D2R binding in nucleus accumbens shell and dorsolateral striatum compared with animals that had limited access to chow. There was no differential binding, however, in the accumbens core in any of the groups. These findings indicate that feeding conditions and sucrose intake influence D2R density specifically in subregions of the striatum.

Fig. 1

[¹²⁵I]iodosulpride binding in the striatum of the restricted fed groups expressed as a percentage of naive controls. The striatal regions examined were the medial shell of the NAcc (shell), core of the NAcc (core), and dorsolateral striatum (DLS). Values indicate mean binding within of each group and error bars indicate SEM. Statistical comparisons shown in this figure reflect difference from naive *p<0.01, p<0.05; with restricted-fed group differences (see results for details) and post-hoc analysis between groups; 1: p<0.05, 2: p<0.05, 3: p<0.01, 4: p<0.01.