BRAIN EXCHANGE: SOMETHING TO CROW ABOUT
By Sean Henahan, Access Excellence
Jolla, CA (3/7/97)
Making a chicken squawk and bob like a quail might seem like the ultimate
stupid pet trick, but by accomplishing this task by cross-species brain
cell transplantation, brain researchers truly have something to crow about.
(Chicken, left; Quail, right)
Dr. Evan Balaban and colleagues at Neurosciences Institute here haddone
considerable ground work to identify parts of the quail and chicken brains
involved with two functions, crowing and head-bobbing. The researchers
then were able to transplant the target cells from two parts of the
brains of Japanese quail embryos into the brains of a two-day-old Plymouth
Rock chickens embryos. They accomplished this by cutting minute holes in
Animals or cells that include components of more than one species are called
chimeras, after the mythical beast that was part goat and part dragon.
The scientists allowed the chimerical chickens to hatch and then observed
the behavior and vocalizations of the birds on videotape. The researchers
were amazed to observe the altered chickens crowing and bobbing in characteristic
quail style. As an additional control, chicken-chicken brain transplants
were also performed, but no behavioral changes were observed.
"To our knowledge, this is the first experimental demonstration that
species differences in a complex behavior are built up from separate
changes to distinct cell groups in different parts of the brain and that
these cell groups have independent effects on individual behavioral components,"
The research has a number of evolutionary and therapeutic implications
for the study of the brain:
Such procedures are not possible, nor are they contemplated in mammals,
including humans, Balaban emphasized.
Suggests that some complex behaviors are 'hard-wired' not learned.
Confirms that these functions are portable
Indicates that separate brain regions are involved in coordinated behaviors
Could help researchers understand how to treat patients with nerve
or brain damage
Could lead to better understanding of neurological disorders in general
The study appeared in the Vol. 94, March 1997 issue of the Proceedings
of the National Academy of Sciences.
Related information on the Internet
Intro. to Brain Chemistry
AE: Monkey Clone
AE: Sheep Cloning
AE Activity: Intro to Fetal Cell Transplantation
AE ACtivity: Chicken Embryology
National Bioethics Advisory