Perinatal malnutrition stimulates motivation through reward and enhances drd1a receptor expression in the ventral striatum of adult mice

AIM The aim of this study was to analyze the effects of protein perinatal malnutrition on the function of dopamine DRD1 and DRD2 receptors in regards to motivation and food consumption in adult mice. The study also analyzed the effect of protein perinatal malnutrition on the gene expression of these receptors in the ventral striatum. METHODS Wistar lineage mice were divided into two groups according to maternal diet: control (17% casein), n=30 and low protein (8% casein), n=30. Between 30 and 120days of life, the following factors were measured: body weight; the effect of dopamine D1 and D2 agonists on the ingestion of palatable food; the motivational aspect under the action of the D1 (SKF 38393) and D2 Quinpirole dopaminergic agonists; and the gene expression of DRD1 and DRD2 receptors in the ventral striatum. RESULTS The body weights of the malnourished animals remained significantly lower than those of the control group from 30 to 120days of life. Malnourished animals ingested a greater quantity of palatable food. There was a decrease in palatable diet consumption in both the control and malnourished groups after the application of D1 and D2 agonists; however, the anorexic effect of the D1 agonist was understated in malnourished animals. Perinatal malnutrition increases the motivational behavior of the animal when food reward is used. There was an increase in gene expression of the DRD1a receptor in the ventral striatum of malnourished animals, and there were no significant changes concerning the DRD2 receptor. CONCLUSIONS Perinatal protein malnutrition stimulates hedonic control of eating behavior by promoting increased intake of palatable foods, possibly due to increased expression of dopamine receptor DRD1a in the ventral striatum.