Altering Hormone Levels in Fetal Brain Affects Risk of Obesity

, altering the hormonal levels of insulin and leptin in the brains of developing fetuses has the potential to modify cellular development in the appetite sector of the brain; these results offer insight to the source of obesity.

The study was performed by researchers from the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (LA BioMed). The researchers utilized fetal neural stem cells from animal models and discovered that levels of leptin or insulin that had been altered had noticeable effects on the brain development of the offspring.

This recent study embellishes upon a previous study performed by LA BioMed, published in Brain Research in March; the findings of that study showed evidence that infants born to nutritionally deprived mothers are “programmed” to consume more food due to the lack of neurons in the region of the brain that controls appetite, indicating that overeating is programmed before birth.

During the course of the study, the researchers discovered that by modifying the levels of leptin in the animal models, neural stem cells developed more neurons; they also discovered that modifying the levels of insulin in the brain enhanced the creation of more astrocytes.

Both actions, however, could only take place at the expense of the development of other brain cells.

Leptin is known to play a role in the brain as a continuous appetite regulator, while insulin serves as an interim appetite regulator.

Significantly, the levels of leptin and insulin are altered in the infants of mothers who suffer from gestational diabetes, inadequate nutrition, or obesity during pregnancy.

"This study shows these two hormones influence the makeup of brain cells and how many cells we develop," stated a principal researcher and corresponding author of the study Mina Desai, PhD. "Our cellular makeup is akin to the foundation for a house. If the foundation isn't constructed properly, you can try and fix it but you will still have a problem. The same is true for people with fewer cells to regulate appetite and maintain stable and proper function of brain."

In this latest study, the researchers found less separation and differentiation of the neural stem cells present in the brains of a newborn with low birth weight in comparison to normal birth weight within the animal models.

These findings correlate with the results of previous studies, which have shown that a small birth weight which is followed by escalated growth is linked to a higher risk of adult obesity, type 2 diabetes, hypertension, osteoporosis, and cardiovascular disease.

Over 60% of American adults are overweight, and 20% are obese; roughly 17% of children and adolescents aged from two to nineteen years old are considered obese in America. This poses as a serious health risk, as type 2 diabetes is present in 11% of children and adolescents.

“By studying the ways in which leptin and insulin communicate with neural stem cells to divide and direct the cell fate, we may one day be able to come up with a new way to combat obesity," said Desai. "We have few effective methods for preventing or treating obesity, even though it is a leading cause of death in our society."

This study is published online in Endocrinology.