Aging tends to rob us of our ability to concentrate, recall facts, and reason, and this decline seems to stem from the fact that older brains generate fewer neurons than they did when they were younger. However, German researchers have discovered a molecule that accumulates with age that inhibits the formation of new neurons. This finding might help scientists design therapies to prevent age-related mental decline.
This molecule, Dkk1 or Dickkopf-1, accumulated in the brains of aged mice. If Dkk1 production was blocked, neurons were born at much higher rates. Dr. Ana Martin-Villalba, the senior author of this work and a member of the German Cancer Research Center in Heidelberg. Said, “We released a brake on neuronal birth, thereby resetting performance in spatial memory tasks to levels observed in younger animals.”
Aged mice that lacked Dkk1 performed just as well in cognitive tests that included memory and recognition tests as younger mice because of the ability of their neural stem cells to self-renew and generate immature neurons.
Younger mice that lacked Dkk1 were less susceptible to developing acute stress-induced depression than normal mice. This seems to indicate that in addition to slowing memory loss during aging, neutralizing Dkk1 could be beneficial in counteracting symptoms of depression.
Martin-Villalba said that there are ongoing clinical trials to test inhibitors of Dkk1 for other medical purposes. “The design of inhibitors that reach the brain might enable the prevention of cognitive decline in the aging population and depression in the general population,” she said.