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KU scientist builds better mousetrap for brain disorders

by Roger Martin

Brain cells just can't shut up.

Lucky for us.

Their ongoing chemical chatter helps us eat, breathe, love, fight, flee and more.

When they send messages to muscles, the result can be movements as precise as a pianist's touch.

Until, that is, monkey wrenches get thrown into the works.

The wrenches may be environmental. Gulf War syndrome causes tremor. Lead poisoning leads to balance difficulties that can show up as exaggerated swaying.

The wrenches may be genetic. That's probably the case in the trembling of early-stage Parkinson's disease or the shaking of essential tremor.

Some of us even throw wrenches into our own works -- consider the case of alcoholics or drug addicts in withdrawal.

Scientists use laboratory animals to study the relationship between brain chemistry and movements gone awry.

They can give mice one drug that causes them to have symptoms of essential tremor, for example, or another that produces a Parkinson's-related circling of the cage.

Then they experiment with drugs to counteract those conditions, hoping to find some that help people.

But studying an animal's movements is difficult.

Observing a mouse's every quiver is tedious and unreliable.

That's where a new invention by a KU professor -- the patent is pending -- comes in.

Steve Fowler calls his instrument a force-plate actometer. It's a plastic box that a mouse can run around in. It's got a lightweight, honeycombed aluminum floor supported at its corners by transducers that measure, on their shafts, the teeniest changes in force.

The floor is wired to a computer that digests and analyzes the mouse's every tic, tremor or sprint.

It even records passages when the mouse doesn't move a lick.

Force-plate technology is at least 30 years old, says Fowler, a professor of human development and family life. Force plates are sometimes used to record the swaying of people with heavy-metal poisoning.

Up till now, though, there's been no device large enough to let the movements of a free animal be tracked and then analyzed by computer.

With his force-plate actometer, Fowler can measure an array of movements.

Sometimes, for example, scientists will give a rat a drug that causes it to move its head rapidly but otherwise be stock-still; the rats are used to test anti-schizophrenia drugs.

The actometer can also measure a mouse that rears up on its hind legs and touches the wall or one that hops clean off the floor.

Fowler and a University of Kentucky colleague once used the actometer to study the posture and movement of old and young rats. The old guys tottered in ways that were nearly undetectable to the human eye.

As long as movements have meanings all their own and as long as we are searching for drugs to control them, there'll be a need for Fowler's brainy mousetrap and other instruments like it.