Athletes know that without constant exercise and training, muscles atrophy. Your teachers and (hopefully) your parents have probably nagged you about similar issues when it comes to your brain. It's been said for years that if one fails to continually exercise his/her brain by learning new tasks, one's mental abilities will also atrophy. Until now however, there's been little scientific proof of this.

That scientific proof seems to have arrived. A recent study in mice now suggests that the survival of newly formed adult brain cells depends on the amount of input they receive. Scientists at the Salk Institute in California performed a study in which the hippocampus region of lab mice brains were infected with a virus that suppressed the ability of new brain cells to produce proteins that allow them to form synapses, or connect.

The hippocampus is the part of the brain involved with learning and memory, which in turn allows for the development of new skills. The virus used attacked only new brain cells - older cells were not affected. What the scientists found was that the infected cells without the protein - called NMDA receptors - died off sooner than those able to form synapses.

In order to confirm these findings,  a control group of infected mice were injected with a compound that blocked all NMDA receptors. This caused uninfected cells to die off sooner, while extending the lifespan of some infected cells. The bottom line - it appears that the activation of these receptors determines the survival of brain cells. When these receptors are not activated, they literally wither and die.

So - how do you activate your NMDA receptors? Learn a new skill - a second language, a musical instrument, or software programming. Study something new. And keep reading our science blogs - you're always bound to learn something new, here!

It has been hypothesized that HIV originated from a certain breed of monkeys. Billions of dollars have already been dedicated to find a cure for HIV, but it seems that a simple protein produced by another breed of monkeys holds the cure to this dreaded disease. According to a research published in the June 2006 issue of the Journal of Immunology, monkeys and lower primates such as the Rhesus macaque produce a type of anti-bacterial protein—called retrocyclin, which the HIV-1 virus resists weakly.

In fact, this protein looks so promising, the University of Central Florida research team behind this finding has received a $4 Million funding to develop a topical microbicide that could prevent transmission of HIV during intercourse. But the research has already gained skeptics.

Nathaniel Landau, a professor at the Salk Institute for Biological Studies, is skeptical of the clinical potential of retrocyclin, noting that the peptide does not inhibit HIV nearly as effectively as other drugs that are being developed. Whether this is the cure or another dead-end, well, only time could tell.