for National Geographic News
Adult moths can remember their "childhoods" as caterpillars, a new study has found.
Recently scientists trained tobacco hornworm caterpillars in the lab to avoid a nail polish-like odor delivered in association with a mild shock.
These bugs then entered the pupal stage and metamorphosed into moths. As adults, they also avoided the nail-polish odor—showing that they had retained their larval memory.
"We concluded that indeed the association does persist and is accessible to the adults in this artificial scenario," said study senior author Martha Weiss, a biologist at Georgetown University in Washington, D.C.
The finding also supports the idea that a piece of the caterpillar brain persists through metamorphosis, she added.
(Related: "Scientists Rethinking Nature of Animal Memory" [August 22, 2003].)
Weiss and colleagues report their research today in the Public Library of Science journal PLoS ONE.
Memory and Metamorphosis
Scientists have long wondered whether memory could survive the dramatic reorganization of the moth brain during metamorphosis, Weiss noted.
"The transition from a caterpillar to a moth or butterfly is really very dramatic," she said.
For example, caterpillars and moths move, eat, and sense the world differently—not to mention appear nothing alike.
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