Mouse Model of Schizophrenia Should Spur Research

WEDNESDAY, Feb. 15 (HealthDay News) -- Scientists say they've developed the first-ever mouse model of schizophrenia, a step that should prove a boon to research into the debilitating disease.

The genetically engineered model, described in the Feb. 16 issue of the journal Neuron, features abnormal activity of the dopamine machinery in a specific area of the brain. This results in cognitive and behavioral impairments that are similar to those experienced by people with schizophrenia.

Dopamine is a major neurotransmitter in the brain that's sent by one neuron to another in order to trigger a nerve impulse in the receiving neuron. It's widely believed that hyperactivity in the brain's dopamine system plays a major role in schizophrenia.

Scientists at Columbia University and elsewhere said their research suggests that cognitive symptoms of schizophrenia may be the result of subtle genetic differences in the dopamine receptor gene that increase receptor activity.

While these genetically engineered mice may prove helpful, rodent models of schizophrenia do have major limitations, the researchers noted.

"The neuronal circuits affected in people are more complex than the analogous circuits in rodents. In particular, the relative size of the prefrontal cortex that is involved in the cognitive deficits is much smaller in rodents than in primates. Some of the cognitive symptoms such as hallucinations or delusions are impossible to address," the researchers wrote.

"However, rodent models have the advantage of allowing direct tests of cause-effect relationships for specific aspects of the disease, such as some of the cognitive deficits," they added. "We here have been able to introduce genetically a single molecular alteration in a restricted and regulated fashion and to study its behavioral and physiological consequences."