The Brainbow technique also incorporates into neurons a genetic mechanism that randomly mixes and matches the genes that direct the production of the blue, green and red proteins. This shuffling system is activated by the presence of a protein called CRE, which causes neurons that produce CRE to turn different colors from other neurons around them.
By inserting Brainbow into a virus, the research team is hoping to design a viral tracer with capabilities that exceed conventional viral tracers being used today, he explained. Current tracers are able to map out entire circuits, but they cannot distinguish among different sections within a given circuit.
Enquist and his collaborators are using genetic engineering techniques to direct certain neurons, such as those that control a particular body function, to produce CRE. When the neurons that have been engineered to make CRE are infected by the new viral tracer, they will be different colors from infected neurons that are not making CRE. This will allow the researchers to see different subcircuits in the brain, Enquist explained.
For example, he is working with J. Patrick Card, a neuroscientist at the University of Pittsburgh, to make neurons in the brainstem involved in blood pressure regulation in mice produce CRE. W
|Contact: Kitta MacPherson|