Experimental drug promising for Alzheimer's

New York.- Bryostatin, a drug that has been studied as an anti-cancer
agent, enhances long-term memory in lab experiments, scientists
report.

"Bryostatin is a promising treatment for Alzheimer's disease, both for
the neurodegeneration -- the underlying cause of the disease -- and
for the symptoms," Dr. Daniel L. Alkon, from Blanchette Rockefeller
Neurosciences Institute in Rockville, Maryland said in a telephone
interview with Reuters Health.

In a previous study in mice, Alkon's team observed that bryostatin
effectively stops the Alzheimer's disease process. It reduces brain
levels of amyloid-beta protein -- characteristic of the disease --
helps prevent premature death, and improves behavior.

Bryostatin has also been shown to enhance learning and memory
retention of rats in a maze task, according to the team's report in
the Proceedings of the National Academy of Sciences.

"Now we've taken this drug and explored in great detail how it may
affect memory itself -- not just neurodegeneration," Alkon said.

To do this the researchers used the snail-like creature Hermissenda, a
biomedical model for learning and memory. Specifically, Alkon and
colleagues found that putting bryostatin in the water days before the
start of learning sessions led to the synthesis of proteins "necessary
and sufficient for subsequent long-term memory formation."

In cultured neurons, bryostatin increased overall protein synthesis by
up to 60 percent for more than 3 days.

"What our study shows is that bryostatin can induce the neurons to
make these proteins days in advance," Alkon said, "and it takes a
training trial or two that ordinarily would produce memory for a few
minutes and turns it into something that lasts for weeks. That was
totally unexpected."

He added, "The beauty of this drug is that it has already been used in
people for years to treat cancer -- although not successfully -- and
therefore we know it is nontoxic."

In addition to Alzheimer's disease, bryostatin may also have a role in
other dementias, Alkon said, "and maybe even for treating people who
need cognitive enhancement such as perhaps people with memory or
learning compromise or those recovering from stroke."

www.today.reuters.com