August 26, 2009

Short- and long-term memory circuits found

U.S. researchers say they've found short- and long-term memories in the fruit fly come from one gene activating different groups of neurons.

Researchers at Cold Springs Harbor Laboratory and Stony Brook University say their discovery challenges the theory that short- and long-term memories result from changes in the same group of neurons.

They found distinct groups of neurons are simultaneously activated when fruit flies learn a task. Rapid, short-lived activation in one group of neurons, called the gamma lobe, results in a short-term memory. Slower, more enduring, activation in another neuron group called the alpha-beta lobe results in a long-term memory. Both memory types depend on the activity of a single gene, a version of which is active in the human brain, the researchers said.

The study supports the idea that there are different anatomical and circuit requirements for different stages of memory, said Assistant Professor Josh Dubnau of Cold Springs Harbor Laboratory, one of the study's authors.

The researchers said their study suggests memory traces form more quickly in one set of neurons than the other, but neurons hosting the slower activation consolidate the memory, resulting in its long-term storage.

The study is reported in the journal Current Biology.