Campus: CSU Northridge -- September 26, 2001
Study from Cal State Northridge biology professor Randy Cohen:
Learning From Rats and Cockroaches
What do rat and human brain cells have in common? What can cockroaches
tell us about our food choices?
A lot, according to Cal State Northridge biology professor Randy Cohen.
Cohen is currently using Han-Wistar rats to look into genetic disorders,
cell death and the causes of diseases such as Alzheimer's, Parkinson's,
epilepsy and Lou Gehrig's. His work with cockroaches may provide insight
into human eating choices.
In one project, Cohen is collaborating with two other professors to find
out what gene (a protein product) is causing genetic disorders.
"That protein product may be some sort of basic protein in this mutated
form that kills cells, and it might be relevant to human neurological
disorders," Cohen said.
He said the main purpose of the study is to answer the question: "If
the gene is killing two different kinds of cells in two areas of the brain,
why is it doing that?"
In another study, Cohen and his students are attempting to learn what
cells do to protect themselves while neighboring cells are dying. They
are looking at what drugs, such as receptor blockers, inhibit cell death,
and what chemicals affect cell function.
"We're interested in which receptors are being activated, changed,
altered, and how the cells know to alter it," Cohen said.
In another project, Cohen is attempting to discover what mechanisms lead
to cell death. According to Cohen, glutamate excitotoxicity (or excitement)
functioning at too high levels can cause cell death, but at a normal level
it functions properly.
"Glutamate excitotoxicity has been implicated in most, if not all,
neurological disorders where there's loss of cells-including Alzheimer's,
Parkinson's, Lou Gehrig's disease, epilepsy and stroke," Cohen said.
He is not sure if glutamate is causing the cells to die in the rats, but
says the rats live longer when the glutamate transmission was blocked.
In his fourth study, Cohen is looking at human disorders. By watching
the rats, he and Ben Yaspelkis, a CSUN kinesiology professor, can research
brain and muscle deterioration, and the changes of the muscle's systems
when there is a neurological problem.
In the case of Alzheimer's, Cohen said, a small percentage of people can
develop the disease between the ages of 40 to 60 or earlier because of
genetics. People in their 80s and 90s usually get the disease because
of severe head traumas. Most people diagnosed with Alzheimer's usually
live two to eight years or more.
Unfortunately, there is only one way to diagnose it - an autopsy of the
brain, Cohen said.
With Lou Gehrig's, the disease usually occurs after age 55.
Cohen and his students also are studying the eating choices of cockroaches.
They are looking at the insects' brain chemicals, which indicate they
make the same food choices as humans.
"Internally, we apparently have similar mechanisms in the brain,"
Cohen said. "So, I'm interested in how the brain controls when you
eat and what you eat."
Cohen received his B.S. in biological sciences from USC in 1976. In 1980,
he received his M.A. in biology from Cal State Northridge. His thesis
was about the interaction between fungi and spiders.
He later got a Ph.D. in entomology from the University of Illinois, Champagne
in 1987. He moved back to California to become a post-doctoral researcher
and a research physiologist at the UCLA School of Medicine in neurophysiology.
In 1994, he became a part-time assistant professor at CSUN and continued
his research at UCLA. He was promoted to associate professor at CSUN in