Researchers have used gene therapy to restore the feeding behavior in mutant mice that lacked the motivation to feed. This study
provides new information about how the brain integrates internal hunger signals with sensory information. Published in the June 2001 issue of Neuron
, the study suggests where in the brain the neurotransmitter dopamine influences feeding behavior.
The mutant mice lacked an enzyme required for dopamine production. Qun-Yong Zhou developed this mouse model in the research lab of team leader Richard D. Palmiter, a Howard Hughes Medical Institute investigator and professor of biochemistry.
The dopamine-deficient mice were uninterested in feeding and would die of starvation without intervention. The mice are also sluggish and have a motor condition that resembles Parkinsonism.
Mark S. Szczypka, postdoctoral fellow in biochemistry, injected recombinant viruses that could restore local dopamine production in the mice. He found that injections into the caudate putamen region of the brain restored feeding.
Injections into other brain regions restored other behaviors, but not feeding. None of the treatment sites corrected the motor deficits.