The Rubin Museum, NYC. Poster for Brainwave 2017, Perception.
Neurogenesis, the growth of new neurons in the brain, only occurs in the hippocampus according to Dr. Majid Fotuhi, whereas, we can create new synapses in the hippocampus and the cortex. The hippocampus is responsible for emotion, autonomic nervous system, and short-term memory such as where we put our car keys or the name of our new professors, the teachers and friends of our children, or the lyrics to the last song you heard right before heading into an exam. The name comes from Latin for seahorse because the hippocampus resembles the S shape of a seahorse. The fact that neurogenesis happens is exciting; that is only occurs in the hippocampus is perhaps unfortunate. If only neurogenesis occurred in all parts of the brain!
Neurogenesis and synaptogenesis, the creation of new synapses, are functions of neuroplasticity, the idea that our brains are malleable and can recover from damage, grow and make new pathways if they are treated well. Our brains thrive on lifestyle behaviors such as healthy food, physical activity, mental stimuli such as novel and complex experiences, enough sleep, stress reducing meditation, and social interactions.
If we feed our brains with healthy lifestyle behaviors—I like to think of these behaviors as fertilizer for our brains—neurogenesis and synaptogenesis will occur creating a more dense and resilient brain, also known as brain reserve. According to Dr. Fotuhi, brain reserve is like money in the bank: the healthier and denser the brain is, the more it is resilient to damage and potential future disease such as Alzheimers.
On the other hand, if we don’t engage in healthy lifestyle behaviors, or if we sustain head injuries such as concussions, the hippocampus will shrink. Shrinking also occurs due to depression and stress.