Friday, 10 March 2006

Brain Swapping

From The Scientist :
For more than two decades, Evan Balaban has honed his skills at manipulating embryonic tissue samples using tiny instruments of his own making. He can cut a small access window into a quail's egg, and using a scalpel no wider than a human hair, excise a few hundred thousand cells from the bird's developing central nervous system. This is only the first step of the intricate process required to place this minuscule brain into another animal's head. Some of these surgeries end in untimely death for brain-transplanted embryos, but Balaban says he has elevated the typical survival rate from less than 20% to more than 60%.
brain swapping is "really working at the right level for answering a lot of interesting questions about brain development and behavior," and techniques are improving all the time. Not until two or three decades ago did biologists understand brain circuitry well enough to make good scientific use of brain transplants, though they have been technically feasible since H.G. Wells' time. Since then, researchers have swapped the brains of various species of frogs and salamanders, as well as ducks, in addition to the quails and chicks that Balaban uses. He plans on trying it on songbirds too.

Transferring brain tissue between embryos has enabled Balaban to examine how birds with implants from different bird species innately prefer the other species' songs. "You [can] make chicken that prefer the quail sound, even more than normal quail do … as if in the chicken, the cells seize more behavioral control," he remarks. Another of his creations, chickens that bobbed their heads up and down like quail while crowing, provides further proof, he says, that some habits are innate rather than learned and can be traced to specific brain structures.

Balaban's work focuses on how nature and nurture blend together to create a seamless set of brain circuits. Other brain-swappers have focused on how brain structure makes males and females different, or how dysfunctional circuitry manifests itself in congenital abnormalities such as epilepsy.

Balaban estimates that there are four or five active brain-swappers worldwide and sees growing interest in the work among molecular biologists.

Emphasis added by me.

Some psychiatrists should really get out more. Do a bit of research outside their immediate discipline. They might find out all sorts of things.

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