Jason Sudeikis’ character is hosting a nice dinner party with his wife played by Jennifer Aniston, and all seems to be going great. Then, all of a sudden, their 12- month-old baby blurts out a curse word! “How could our baby learn such a thing?” In a flashback 8 months earlier, we see the less-experienced parenting pair blurt out some pretty R-rated things in a fit of frustration on the road with their baby in the backseat. And so the punch line sinks in.
In modern day parenting comedies, scenes like this fabricated one are a dime a dozen. But these humorous takes on life always get at least one thing right: babies are sponges. Let’s take a look at why on a cellular level.
Prior to birth, most neurons migrate to the frontal lobe of the brain where, during postnatal development, they link together and forge connections, allowing a baby to learn proper responses to stimuli. The “circuits” formed by the neural connections are incredibly flexible during the early months of development (roughly the first 6 months) and can quickly be formed or severed, resulting in a remarkable neonatal human ability to rapidly pick up new knowledge about our surroundings. But how are they so malleable?!
Researchers at the University of California, San Francisco may have the answer! In a study coauthored by neuropathologist Eric Huang, they found neurons forming a chain moving towards the frontal lobe from the sub ventricular zone, a layer inside the brain where nerve cells are formed, in infants up to 7 months old!
This research seems to point to the idea that these new brain cells form connections with the pre-existing neurons in the frontal lobe later in the infant’s development, resulting in more cognitive flexibility for a longer period of time.
To quote the original article by Laurel Hamers, what the new neurons are doing is analogous to “replenishing the frontal lobe’s supply of building blocks midway through construction”.
Huang’s team observed postmortem infant brain tissue under an electron microscope and discovered a group of neurons synthesizing migration proteins, but the real major discovery came with the observation of rare tissue acquired moments after death. The team injected viruses tagged with glowing proteins into the neurons (thus making the nerve cells glow) in the sample and tracked their movement. While infants up to 7 months old were observed with migrating neurons, the researchers recorded the number of migrating cells at its highest at 1.5 months old and saw it diminish thereafter. The migrating neurons usually become inhibitory interneurons which, to quote the original article, are “like stoplights for other neurons, keeping signaling in check”.
So there you have it! To make sure your baby doesn’t learn that bad word, just suck up all the migrating neurons from its brain!
All jokes aside, this research presents an amazing window into the brain development of the most intelligent species on earth! It’s fascinating how it breaks down psychological mysteries using cellular evidence. And it raises new questions about these mobile neurons: When are they created and how long does it take them to move to the frontal lobe?
How do you think this new research will influence our understanding of the creation of social biases? Do you think this will lead to breakthroughs in research on the foundation of Autism spectrum disorders? Do you have any funny baby stories? Let me know in the comments.