GENETIC REGULATION OF CORTICAL SPECIFICATION

The degree to which our genetic endowment versus our experiences molds the development and function of our brains has been the interest for many scientists in the past decades. The new evidence indicates that the development of functional areas in the cerebral cortex, such as motor activity versus learning, involves a rich array of signals and effectors, with considerable interplay between genetic mechanisms intrinsic to neurons and extrinsic mechanisms requiring neural activity. Therefore, although our brain is genetically determined, individual experiences translated into neural activity, are able to modulate our way of thinking and responding to external stimuli. This study aims to a better comprehension of the mechanisms on how our brain develops. With the help of a series of genetic tools in the mouse, we can dissect the intrinsic and extrinsic components, and study them in an isolated fashion. We found that by mutating a single gene all the sensory maps, that reflect experience and learning, are reduced in the mouse brain. Conversely, the motor area is expanded, suggesting that individual genes are involved in modulating specific areas, and that by affecting one area, the brain adapts and expands adjacent ones. In addition, the same gene can affect the connections that bring inputs to the cortex and influence in this way the size of the different areas. We are now trying to understand the molecular mechanisms behind these different phenomena and the physiological consequences of altered size and location of functional areas and circuits by using a series of behavioral tests.