Study finds lifelong neurogenesis in the hippocampus, but rates decline with age and, especially, Alzheimer ’s disease

Recent, immature neurons (in red) and older, mature neurons (in blue) in the hippocampus of a 68-year-old’s brain. Credit: CSIC ___ Old brains still make neurons, study finds, offering a possible way to protect against Alzheimer’s (STAT): “Reports of old brains’ decrepitude have been greatly exaggerated, scientists reported on Monday, unveiling results that contradict a much-discussed 2018 study and instead support the idea that human gray matter is capable of generating new neurons up to the ninth decade of life. The research, published in Nature Medicine, also found that old brains from people without dementia have much higher rates of such neurogenesis than do the brains of people with Alzheimer’s disease, offering a new clue to a field that is desperate for new ideas… In a 43-year-old brain, for instance, the scientists measured roughly 42,000 new neurons per cubic millimeter of hippocampus (approximately the volume of nine grains of table salt). An 87-year-old had 20,000 new neurons per cubic millimeter… Although Llorens-Martín and her colleagues did not have enough brains of the same age to make definitive comparisons of individual neurogenesis rates, they saw hints of person-to-person variation. Among people in their 60s without Alzheimer’s, she said, rates of neurogenesis ranged from about 30,000 to 40,000 new neurons per cubic millimeter of hippocampus; in 80-somethings, it was 20,000 to 30,000. “If you can increase the rate of neurogenesis, it mig...
Source: SharpBrains - Category: Neuroscience Authors: Tags: Cognitive Neuroscience Education & Lifelong Learning Health & Wellness adult hippocampal neurogenesis age Alzheimer’s Alzheimer’s Disease dementia hippocampus Neurons Source Type: blogs