Maternal Caloric Restriction Implemented during the Preconceptional and Pregnancy Period Alters Hypothalamic and Hippocampal Endocannabinoid Levels at Birth and Induces Overweight and Increased Adiposity at Adulthood in Male Rat Offspring.

Exposure to inadequate nutritional conditions in critical windows of development has been associated to disturbances on metabolism and behavior in the offspring later in life. The role of the endocannabinoid system, a known regulator of energy expenditure and adaptive behaviors, in the modulation of these processes is unknown. In the present study, we investigated the impact of exposing rat dams to diet restriction (20% less calories than standard diet) during pre-gestational and gestational periods on: (a) neonatal outcomes; (b) endocannabinoid content in hypothalamus, hippocampus and olfactory bulb at birth; (c) metabolism-related parameters; and (d) behavior in adult male offspring. We found that calorie-restricted dams tended to have a reduced litter size, although the offspring showed normal weight at birth. Pups from calorie-restricted dams also exhibited a strong decrease in the levels of anandamide (AEA), 2-arachidonoylglycerol (2-AG), arachidonic acid (AA) and palmitoylethanolamide (PEA) in the hypothalamus at birth. Additionally, pups from diet-restricted dams displayed reduced levels of AEA in the hippocampus without significant differences in the olfactory bulb. Moreover, offspring exhibited increased weight gain, body weight and adiposity in adulthood as well as increased anxiety-related responses. We propose that endocannabinoid signaling is altered by a maternal caloric restriction implemented during the preconceptional and pregnancy periods, which might lead to modifications of the hypothalamic and hippocampal circuits, potentially contributing to the long-term effects found in the adult offspring.

Exposure to a Highly Caloric Palatable Diet During Pregestational and Gestational Periods Affects Hypothalamic and Hippocampal Endocannabinoid Levels at Birth and Induces Adiposity and Anxiety-Like Behaviors in Male Rat Offspring.

Exposure to unbalanced diets during pre-gestational and gestational periods may result in long-term alterations in metabolism and behavior. The contribution of the endocannabinoid system to these long-term adaptive responses is unknown. In the present study, we investigated the impact of female rat exposure to a hypercaloric-hypoproteic palatable diet during pre-gestational, gestational and lactational periods on the development of male offspring. In addition, the hypothalamic and hippocampal endocannabinoid contents at birth and the behavioral performance in adulthood were investigated. Exposure to a palatable diet resulted in low weight offspring who exhibited low hypothalamic contents of arachidonic acid and the two major endocannabinoids (anandamide and 2-arachidonoylglycerol) at birth. Palmitoylethanolamide, but not oleoylethanolamide, also decreased. Additionally, pups from palatable diet-fed dams displayed lower levels of anandamide and palmitoylethanolamide in the hippocampus. The low-weight male offspring, born from palatable diet exposed mothers, gained less weight during lactation and although they recovered weight during the post-weaning period, they developed abdominal adiposity in adulthood. These animals exhibited anxiety-like behavior in the elevated plus-maze and open field test and a low preference for a chocolate diet in a food preference test, indicating that maternal exposure to a hypercaloric diet induces long-term behavioral alterations in male offspring. These results suggest that maternal diet alterations in the function of the endogenous cannabinoid system can mediate the observed phenotype of the offspring, since both hypothalamic and hippocampal endocannabinoids regulate feeding, metabolic adaptions to caloric diets, learning, memory, and emotions.