"Figuring out where and how long animal brains store information about past choices can help us more broadly understand models of decision-making," says Jeremiah Cohen, Ph.D., assistant professor of neuroscience at the Johns Hopkins University School of Medicine. Eventually, he says, such models could lead to better treatments for addiction and other disorders marked by flawed or disordered decision-making.
A description of the studies was published July 4 in the journal Neuron.
Experiments - Cohen - Colleagues - Johns - Hopkins
For the experiments, Cohen and his colleagues at Johns Hopkins used various odors to train 36 mice to choose between two tubes that deliver water when licked and which were randomly controlled by a computer to turn the "faucets" on or off. When one tube was turned on, the other was turned off, and then, they'd switch. The experiment was designed to mimic how mice forage for water in the wild and learn where to return for the liquid.
The mice didn't know, with certainty, whether they would receive water when they made a particular choice, says Cohen. To find the water reward, they had to remember their recent choices and outcomes, he explains.
Cohen - Mice - Water - Tubes - Amount
As expected, Cohen says, the mice more often explored and licked from water tubes that were turned on more frequently, maximizing the amount of water they received. Occasionally, they also explored water tubes that were turned off, licking them once in a while. When a tube with plentiful water was turned off, the mice switched to the other tube that was newly turned on, says Cohen. The scientists also found that the mice waited to make their water tube choices for up to half a minute.
Cohen says previous studies over the past decade have suggested that decision-based memories are stored in the prefrontal cortex -- the seat of complex behavior, personality and learning.
To figure out where in their...
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