Researchers Find Cues for New Neuron Growth

In a recent study published in the Journal of Neuroscience, researchers from the University of Washington examined the brain’s ability to replace cells that have been lost naturally. Neuroscientists have long known that new neurons are generated in the adult brains of many animals, but the birth of new neurons — neurogenesis — appears to be limited in mammals and humans, especially where new neurons are generated after there’s been a blow to the head, stroke or other physical loss of brain cells. During the study, the researchers worked with white-crowned sparrows, a medium-sized species that breeds in Alaska, then winters in California and Mexico. During the study, the researchers described the series of events that cues new neuron growth each spring, starting with a signal from the expiring cells the previous fall, which primes the brain to start producing stem cells. Like most songbirds, white-crowned sparrows experience growth in the area of the brain that controls song output during the breeding season when a superior songs helps them attract mates and define their territories. Additionally, the sparrows’ breeding cycles are closely tied to the amount of sunlight they receive. “As the hormone levels decrease, the cells in the part of the brain controlling song no longer have the signal to ‘stay alive,’” said the study’s lead author. “Those cells undergo programmed cell death — or cell suicide as some call it.” If scientists can further tap into the process and understand how those signals work, it may lead to ways to exploit these signals and courage replacement of cells in human brains that have lost neurons naturally because of aging, severe depression or Alzheimer’s disease. To read more about this study, click here.