Scientists discover a major brain shift between ages 50 and 75

Scientists have uncovered sweeping changes in how the human brain controls and organizes its genome beginning in midlife, offering new clues to why aging sharply increases the risk of Alzheimer’s and other neurodegenerative diseases. One of the biggest shifts occurred between about ages 50 and 75, when many of the brain’s original immune cells declined and were replaced by cells with more inflammatory characteristics. Researchers also found weakening of cells that help maintain the blood-brain barrier, along with widespread deterioration in the genome’s three-dimensional organization.

Scientists discover a major brain shift between ages 50 and 75. Scientists discover a major brain shift between ages 50 and 75 Science News from research organizations Scientists discover a major brain shift between ages 50 and 75 Aging appears to trigger a major biological transformation in the human brain beginning around midlife. Com Researchers have found that the human brain begins undergoing broad changes in the way its genome is regulated starting in midlife.

The findings may help explain why age is the strongest risk factor for neurodegenerative conditions such as Alzheimer’s disease. In a new study published in Science, scientists used advanced single-cell methods to examine gene regulation and three-dimensional genome organization in individual cells from the human hippocampus, a brain region essential for learning and memory. By analyzing samples from adults across many ages, the team created one of the most detailed pictures yet of how genome regulation shifts as the brain grows older.

Brain Immune Cells Undergo a Major Midlife Shift One of the most notable changes appeared in microglia, the immune cells that help maintain and protect the brain.