New research from Michigan State University reveal that microbes play an important role in the formation of early brain development, especially in a key brain region that controls stress, social behavior and vital body functions.
The study, published in Hormones and behaviorUsed a mouse model to emphasize how natural microbial exposure has not only an impact on the brain structure immediately after birth, but can even start to influence development while being in the uterus. A mouse model has been chosen because mice share important biological and behavioral similarities with humans and there are no other alternatives to the study The role of microbes on brain development.
This work is important because modern obstetric practices, such as the use of peripartum antibiotics and the cesarean, disrupt maternal microbes. In the United States only, 40% of women receive antibiotics around childbirth and a third of all births occur via a cesarean.
At birth, a newborn baby is colonized by microbes when he moves through the birth channel. Birth also coincides with important development events that shape the brain. We wanted to explore more how the arrival of these microbes can affect the development of the brain. “”
Alexandra Castillo Ruiz, principal author of the study and assistant professor in the MSU psychology department
The research team focused on a region of the brain called the paraventricular nucleus of the hypothalamus (PVN), which plays a central role in the regulation of stress, blood pressure, water balance and even social behavior. Their previous work had shown that mice raised without microbes, or germ -free mice, had more dying neurons in PVN during early development. The new study decided to determine whether this increased cell death resulted in changes in the number of long -term neurons, and if effects could be caused by the arrival of microbes at birth or if they started in the uterus via signals from maternal microbes.
To find out, the researchers used a cross -approach. Newborn germ mice have been placed with mothers who had microbes and compared them to control groups. When the brain of these mice was examined only three days after birth, the results were striking: all the mice gyed by germ -free mothers had fewer neurons in the PVN, which they received microbes after birth. They also found that germ -free adult mice had fewer neurons in the PVN.
“Our study shows that microbes play an important role in the sculpture of a brain region which is essential for bodily functions and social behavior. In addition, our study indicates that the microbial effects begin in the uterus via signaling from maternal microbes, “said Dr. Castillo-Ruiz.
Rather than avoiding our microbes, we must recognize them as partners in the development of the beginning of life, “said Dr. Castillo-Ruiz. They help build our brain from the start. “”