There was an intriguing article in Scientific American last week called “Think Twice: How the Gut’s ‘Second Brain’ Influences Mood and Well-Being.” Although I work at a neuroscience company, I was unfamiliar with the “second brain.” It turns out it’s a mass of tissue in our intestines that shares many qualities with our brains–millions of neurons, many of the same key chemicals (like dopamine and serotonin). This “second brain” is officially called the “enteric nervous system,” and it’s a fascinating part of the body.
Here’s a little context: As you probably know, the brain and spinal cord are known as the “central nervous system.” The central nervous system receives and makes sense of information from other parts of the body (such as “ouch! that hurt!”). It also sends messages out (such as “right hand: wave good bye”). The “peripheral nervous system” connects the central nervous system to the rest of the body, moving the messages along until they reach their destination. The enteric nervous system (the “second brain”) is part of the peripheral nervous system.
What makes the “second brain” unique from other parts of the peripheral nervous system, though, is that it can function even without input from the central nervous system, and sends many more messages to the central nervous system than it receives. And while it’s not a center of conscious thought, it has widespread influence on our physical bodies and our emotional well-being. This may have implications for how we treat emotional problems like depression.
I encourage you to read the article to find out more about this fascinating “second brain.” I certainly learned something new about how my brain(s) work!