Brisbane: People suffering from dementia can heave a sigh of relief as neuroscientists in Australia have discovered a fundamental component of the process that regulates memory formation.
   
Neuroscientists at the Queensland Brain Institute (QBI) of The University of Queensland discovered the component in the hippocampus – a part of the brain commonly associated with memory function.
     
The discovery explains, for the first time, how new nerve cells form in this area of the brain associated with learning and memory – which deteriorate in people with stroke and dementia, QBI Director Professor Perry Bartlett told the media.
   
"The hippocampus is the region of the brain involved in important functions such as learning and memory, and loss of neuronal production in the hippocampus is associated with a range of neurodegenerative conditions. It is particularly evident in ageing dementia," Bartlett said.
   
"Surprisingly, however, studies so far have failed to identify a resident stem cell population in the hippocampus that's capable of providing the renewable source of these essential nerve cells."
   
Research by Professor Bartlett and his QBI colleagues, Dr Tara Walker and Dr Dhanisha Jhaveri (a recipient of the Indian National Science Academy's award for Young Scientist of the Year 2003), has identified the resident populations of stem cells in the hippocampus.
   
Even more importantly, this research has discovered how it can be activated to produce new neurons.
   
The discovery of the presence of precursors in the adult brain which have the potential to produce neurons via a process called neurogenesis, will help immensely in the case of dementia patients, Bartlett said.
   
"For the first time, we've been able to identify a mechanism that's able to regulate production of nerve cells, a step that's crucial to our understanding of memory and learning," Professor Bartlett said.
   
"The same mechanism helps regulate growth of healthy brain tissue, so identifying this process is essential for the development of therapeutics to treat conditions such as dementia and depression."
   
A detailed understanding of the activation process should enable the development of therapeutics that can stimulate the production of new neurons and reverse or prevent the cognitive decline that occurs during ageing dementia, he said.
   
"These significant advances in determining the molecular regulation of nerve production will also have a major impact on our understanding of more complex areas such as behaviour, cognition, neurological disease and mental illness," he added.
   
He said that the latest research provides further evidence that the mammalian central nervous system has the potential capacity to respond to its outside environment by generating new nerve cells.
   
The QBI research augments ongoing efforts to identify cellular and molecular mechanisms that can repair compromised brain tissue, and represents another milestone in understanding the fundamental workings of the brain.

(Agencies)