New Strain of Mice May Help in Studies of Brain Circuitry

Researchers have created a strain of mice that lack a key component of a brain communication system--a step that could shed light on drug addiction, Parkinson’s disease and schizophrenia.

The mice will help researchers understand brain cell circuits that communicate with a chemical messenger called dopamine.

In these circuits, one brain cell signals another by releasing bits of dopamine. Then it retrieves the dopamine with a structure called a dopamine transporter, which terminates the signal.

Mice in the newly created strain have no dopamine transporter because of a genetic defect. As a result, dopamine persists 300 times longer than usual in the tiny spaces between nerve cells, delivering its signal for an abnormally long time, researcher Marc G. Caron said.

That makes the mice hyperactive, as if they had been given cocaine or amphetamines, Caron, a cell biologist at Duke University, reported in Nature.