During pregnancy, an atrocious desire to eat a specific food may appear, they are called cravings. Now, a study has discovered the neural mechanisms responsible for this sudden need in pregnant women, indicating that it is due to a reorganization of the dopaminergic circuits related to desire and motivation.
The research carried out by Spanish scientists, which has been published in the journal Nature Metabolism, has been carried out on a group of pregnant female mice whose brain activity and dopamine levels have been analyzed during pregnancy. In addition, the authors have studied the possible consequences of these cravings in the offspring.
And it is that, during pregnancy, the woman’s body undergoes a series of physiological and behavioral changes that are aimed at creating an environment that is favorable to the development of the fetus. However, cravings could put this at risk, since most of them are usually oriented towards sweet or caloric foods, which increase the risk of weight gain and gestational obesity, in addition to being a problem for babies.
According to the findings of this work, the brains of female mice undergo notable changes in functional connections related to reward, gustatory and sensorimotor circuits. “The alteration of these structures led us to explore the mesolimbic pathway, one of the signal transmission routes of dopaminergic neurons. Dopamine is a key neurotransmitter in behaviors of motivation or desire”, explained Marc Claret, IDIBAPS group researcher and leader of the study.
Noticeable increase in dopamine levels
In mice, it was observed that both dopamine levels and D2R receptor activity increased in the nucleus accumbens, which is a brain area responsible for the reward circuit. This could indicate, as they explain, that pregnancy causes a complete reorganization of mesolimbic neuronal circuits through D2R neurons.
The brains of pregnant mice had changes in the connections associated with reward, taste and sensorimotor circuits
“Likewise, these neuronal cells, and their alteration, would also be responsible for the appearance of cravings, since the anxiety for food, typical of pregnancy, disappeared after blocking their activity”, explains Roberta Haddad-Tóvolli, another of the authors.
Regarding the possible risks of these sudden food cravings for offspring, the authors found evidence indicating that persistent cravings could affect babies’ metabolism and the correct development of the neural circuits that are responsible for regulating food intake . This fact makes them gain body weight, they are more likely to have eating disorders and develop anxiety.
“These results are surprising, since most studies focus on analyzing how the mother’s permanent habits, such as obesity, malnutrition or chronic stress, affect the baby’s health. However, our work indicates that in order to increase the psychological and metabolic vulnerability of the offspring, short but recurrent behaviors such as cravings are enough”, explains Claret.
The findings of this study could contribute to improving the nutritional clinical guidelines available for pregnant women, in order to guarantee adequate prenatal nutrition and help prevent the appearance of possible diseases, both in the mother and in the baby.
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