Nature reveals: Why do pregnant women eat so much?

Reproduction leads to increased food intake in many species of females, which provides physiologically relevant examples for the exploration of appetite regulation.
, however, the link between internal state and gastrointestinal nerve dominance remains unclear.
October 28, researchers at the LONDON School of Medicine in the United Kingdom used simple but physiologically complex fruit fly intestines to determine the key role of intestinal neurons with gender and reproductive state-specific activities in maintaining an increase in food intake during the mother's reproduction.
results were published in Nature.
fruit fly has a stomach-like organ called "crop", an extensable structure found in the insect's intestines.
organs and the frontal intestine are dominated by muscle inhibitor (MS) positive neurons located in the central (PI) and lower brain nerve nodes (HGG).
, the researchers selectively activated or silenced ms neurons in adult fruit flies.
found that activating the "crop" of fruit flies that led to free eating increased significantly, compared with the "crop" expansion of silent Ms neurons when hungry.
(in this case, the fruit fly's "stomach" usually expands) in addition, Ms's gene reduction or mutation also prevents the expansion of "crop", although it is less silent than Ms neurons.
further studies have shown that PI Ms neurons induce the growth of "crop" by producing Ms neuropeptides, which are indispensable for their growth, while myosin-inhibitor-1 (MsR1) regulates the "crop" growth muscle-like body through the Ms signal.
estypes caused by the activation or silence of Ms neurons driven by Ms and MSR1 on the expansion of the crop (a-c: ms neurons driven by Ms-Gal4).
: Ms's downgrade can significantly reduce the "crop" area by using the Taotie-Gal4 drive instead of the Mip-Gal4 drive.
e:Ms subject system development.
) Next, the researchers looked at the expanded physiological regulation of "crop" and found that it depended on gender and reproductive status: the female fruit fly's "crop" after free-eating mating always expanded more than that of free-eating unsopened females or mating males, and only after mating did the female's PI neuron cells have lower levels of Ms peptides.
, compared with un mating females, mated female Ms neurons had higher cumulative calcium levels and lower calcium oscillations.
tests of GCaMP6 calcium imaging in the body and the calcium-sensitive reporting molecule CaLexA showed that GFP (Ms reports with endologic labels) expression was directly related to cumulative neuron activity.
further findings support the hypothesis that in female flies, the activity of PI Ms neurons changes after mating to facilitate the release of Ms.
The reproductive regulation of Ms neurons (a,b: representative anatomical intestinal (a) and MS staining (b)c, d: intransifected (c) or mated (d) female PI in ms-driven GCaMP6 activity) but how did the activity of MS neurons change? The researchers found that steroid hormones and endocrine hormones in the intestines communicate mating status to the brain.
these hormones change the activity of Ms neurons by their role in the pIS neurons, thus facilitating the release of Ms after mating.
to study the importance of ms neuron regulation after mating, the researchers used two separate strategies to reduce MSR1 in the adult fruit fly "crop" and selectively prevented the "crop" from expanding after mating.
results showed no significant effect on males or un mated females, but prevented the normal observed increase in food intake by female fruit flies after mating.
similar results can be obtained by blocking the input of the post-mating molting hormone and the metamorphic hormone bursicon α into Ms neurons.
after selectively preventing "crop" expansion after mating by lowering MSR1, the researchers found that female fruit flies produced fewer eggs and less vitality.
, they concluded that the neurodegenerative control of "crop" and its Ms after mating maintains an increase in food intake, maximizing female reproduction.
after mating, Ms-mediated "crop" expansion increased food intake and reproductive production overall, and the study showed that steroids and endocrine hormones functionally reshaped intestinal neurons, causing their neuropeptides to be released into the "crop" muscles after mating.
release of neuropeptides changes the dynamics of "crop" expansion, leading to an increase in food intake.
the human digestive system may be similarly regulated by reproductive cues, which can affect food intake, " the researchers stressed.
We recommend that pregnancy and lactation be attractive and relatively untapped physiological adaptations to study nutrient intake regulation, organ remodeling and metabolic plasticity, which may eventually be used to suppress appetite and/or weight gain.
" Reference: s1.