EUGENE, Ore.--(Aug. 14, 2006)--University of Oregon biologist Nathan Tublitz talked about moths, flies and cephalopods, telling an audience of scientists meeting in Australia this week that research on these spineless creatures is unveiling the mechanics of how the brain regulates behavior.
Among his tales of three invertebrates were details of his discoveries, published in two papers this year, that two specific brain chemicals (glutamate and FMRFamide-related peptides), residing in a specific location, allow a cuttlefish (cephalopod) to change skin color or skin patterns in less than a second. In a paper that appeared online July 25 ahead of regular publication in the journal Integrative and Comparative Biology, Tublitz and colleagues announced that the quick-change machinery resides primarily in the posterior subesophageal mass of the cuttlefish brain.
Color change in cuttlefish skin is caused by pigments in star-shaped cells known as chromatophores. Upon certain inputs, pigment granules spread outward in cells, causing human skin, for instance, to tan or a chameleon's skin to turn between green and brown. However, such changes take hours in humans and minutes in lizards. Cephalopods have some two million chromatophores that are directed by chemical signals originating in a central brain location. They change colors for camouflage or to communicate with like or different species, Tublitz said.
"The region we've identified is similar to the human motor cortex," Tublitz said in his presentation Tuesday morning in Sydney (5 p.m. Monday Pacific Standard Time) at the Association of Pacific Rim Universities' Brain & Mind Research Symposium. "There is a similar mapping of the cuttlefish brain onto the body as in the homunculus of the human motor cortex. Once we understand that similarity, we can start to understand how these cuttlefish brain cells receive different inputs that cause different types of complex body patterns. We want to k
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Contact: Jim Barlow
jebarlow@uoregon.edu
541-346-3481
University of Oregon
14-Aug-2006