Neural changes help guide decisions in motherhood

In recent years, scientists have begun to unravel the structural changes that take place in a woman’s brain during pregnancy and after childbirth.

One study published in Nature Neuroscience showed that brain remodeling persists for as long as two years after a child is born, and the modifications may play a key role in the transition to motherhood.

A new study from the Society for Neuroscience has produced even more evidence that neural modifications help moms adapt. Using a mouse model, the researchers found that motherhood takes over the brain’s decision-making regions to prioritize caring for offspring. 

The brain’s medial prefrontal cortex (mPFC) filters relevant information to help us make decisions. This process often involves choosing between conflicting stimuli that can be very powerful, such as when a mother who is addicted to drugs must decide whether to seek drugs or care for her child.

The infralimbic and prelimbic cortices of the (mPFC) have been shown to control behavior in different ways. The prelimbic cortex has been implicated in the expression of drug-seeking behavior, while the infralimbic cortex is thought to suppress such behavior.

The most effective addiction therapies for new moms emphasize the relationship between the mother and infant. With this in mind, the study authors theorized that there must be a region of the brain that guides a mother to prioritize offspring over drugs.

To investigate, the researchers temporarily deactivated the infralimbic and prelimbic cortices  in mice and then gave them the choice between a room with their pups or a room with cocaine. Prior to this trial, 40 percent of the mice showed a preference for their pups, 40 percent showed a preference for cocaine, and 20 percent were neutral.

The study revealed that when the infralimbic cortex was deactivated, none of the mice chose the pup room and 78 percent chose the cocaine room. On the other hand, when the infralimbic cortex remained active, most mice selected the pup room and none entered the room with drugs.

The researchers concluded that during motherhood, the brain recruits the power of the infralimbic cortex to prioritize caring for offspring over competing inclinations. The study showed that when the infralimbic cortex was shut down, mothers were less protective and nurturing toward their babies.

The research is published in the Journal of Neuroscience.

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By Chrissy Sexton, Earth.com Staff Writer