Washington: Scientists have discovered a molecule which stimulates the brain to make neurons, a major finding which they claim could pave the way for new treatments to slow down the effects of dementia.
An international team, led by the University of Queensland, says it`s, in fact, one step closer to developing new therapies for treating dementia, reported `The Journal of Neuroscience` in its latest edition.
Team leader Dr Jana Vukovic said the work was aimed at understanding the molecular mechanism that may impair learning and memory in the ageing population.
"Ageing slows the production of new nerve cells, reducing the brain`s ability to form new memories. But our research shows for the first time that the brain cells usually responsible for mediating immunity, microglia, have an inhibitory effect on memory during ageing.
"Furthermore, they have shown that a molecule produced by nerve cells, fractalkine, can reverse this process and stimulate stem cells to produce new neurons," he said.
The discovery came after the scientists observed that the increased production of new neurons in mice that were actively running was due to the release of fractalkine in the hippocampus -- the brain structure responsible for specific types of learning and memory, a release said.
Prof Perry Bartlett, a team member, said it was known for some time that exercise increased the production of new nerve cells in the hippocampus in young and even aged mice.
"But this study found that it is fractalkine that appears to be specifically mediating this effect by making the microglia produce factors that activate the stem cells that produce new nerve cells.
"Once the cells are activated they divide and produce new cells, which underpin the animal`s ability to learn and form memories. This means that fractalkine may form the basis for the development of future therapies.
"The discovery is especially exciting because we have found that older animals suffering cognitive decline showed significantly lower levels of fractalkine. We are seeking ways of increasing fractalkine levels in patients with cognitive decline, and hoping this may be a new frontline therapy in treating dementia," he added.