What is neurogenesis?

Neurogenesis is the formation of new neurons in the brain. While it is robust in the developing nervous system of both animals and humans, the occurrence of neurogenesis in the adult brain is a topic of excitement and some contention within the scientific community. According to Andrew Huberman, neurogenesis does happen in the adult brain and is an exciting concept. However, he emphasizes that the amount of neurogenesis that occurs in the adult human brain is very small when compared to other mechanisms of neuroplasticity such as long-term potentiation and depression, and it is not the main process for the formation of short and long-term memories. Dr. Huberman points out that cellular changes in the brain are mostly due to the strengthening or weakening of synapses, rather than the addition of new neurons 1.

Additionally, Dr. Huberman mentions neurogenesis occurs in the dentate gyrus, a region of the hippocampus involved in learning and memory. Exercise, in particular cardiovascular exercise, has been shown to potentially increase the proliferation of new neurons in this structure 2. However, while this idea has generated popular interest, in the grand scheme of neuroplasticity, neurogenesis is not considered the dominant way that the adult human brain rewires itself. Rather, changes in neural circuitry typically come from the addition or strengthening of existing connections or the elimination or weakening of others 3.

Furthermore, hormonal signals promoted by exercise might be more beneficial than an increase in the number of neurons. Dr. Huberman argues that the adult brain does not handle the addition of entirely new neurons very efficiently, suggesting that hormonal pathways may have a more significant role in promoting brain health and cognitive function related to exercise 4.