GENE chips are allowing researchers to fish for genes involved in complex
neurological diseases and brain development.
These 鈥渕icroarrays鈥� let scientists measure the activity of thousands of genes
at a time. We can pick out genes that we would never have thought to test, says
Pat Levitt of the University of Pittsburgh. 鈥淚t鈥檚 a hypothesis-free system.鈥�
Levitt鈥檚 group looked at the activity levels of 7000 genes in post-mortem
brain tissue from 22 people with schizophrenia. There was a big decrease in the
activity of several genes, but just one was common to all of the samples.
Advertisement
The gene produces a regulatory protein named RGS-4. This affects the length
of time a chemical neurotransmitter interacts with its target when neurons
communicate with each other across junctions called synapses. In patients with
schizophrenia, a low level of RGS-4 could mean that each synaptic signal
continues a little longer than normal.
鈥淥ur hypothesis is that there may be too much signal, so the system turns
down how often it is released, to compensate,鈥� he says.
Other researchers have begun to test for gene differences that may drive
disorders such as Huntington鈥檚 and Alzheimer鈥檚, as well as mouse models of
bipolar disorder and even drug-craving.
Around half of all our genes are active only in the brain, so such technology
could save years of effort for researchers investigating brain disorders, says
Levitt. But at present the most complete chips are out of the reach of basic
research. Only the pharmaceuticals industry can afford them. 鈥淚f these were
available to us, research would progress a lot quicker,鈥� he adds.
