A Specific Part of Your Brain Seems to Shrink If You Have Depression - ScienceAlert

Freedivers repeatedly experience hypoxia while holding their breath underwater. (Matt Porteous/Stone RF/Getty Images) It's extremely not very good for your brain to deprive it of oxygen. Starved of the oxygen they need to produce energy, your neurons can start dying within minutes, rapidly leading to seizures, unconsciousness, and death in the most extreme cases. A seahorse-shaped region called the hippocampus is particularly vulnerable to this hypoxia. It's deeply involved in forming and retaining memories, as well as our ability to navigate the physical world. Yet there are people in this world who voluntarily and repeatedly put themselves under hypoxia. These are the freedivers, performing an extreme sport that involves holding one's breath for minutes at a time while diving into deep waters. The record for this is held by Croatian freediver Vitomir Maričić, who held his breath for an astonishing 29 minutes and 3 seconds at the bottom of a diving pool. But, puzzlingly, these athletes don't appear to show the impaired memory function we might expect from repeated hypoxia. Now, a team led by neuroscientist Julia Micaux of the University of Paris-Saclay may have figured out how.