Neuroanatomical Considerations Specific to the Study of Neurogenetics

There is a great need to understand the fundamental bases of complex behaviors such as language, memory, attention, music, emotion and affect, mathematical thinking, executive functions, visual cognition and mental imagery, and consciousness. These behaviors arise from intricate, developmental, and on-line interactions between genes and environment, having their ultimate effects at the molecular level. This understanding is difficult to achieve, as the interrelationships between genes and environmental factors that control the serial and parallel molecular events that build, adapt, and maintain the extremely complex neural structures that support these behaviors are great. The ultimate promise of neurogenetics research is the understanding of at least part of the molecular basis of behavior, which has to do with the influence of hard-wired genetic factors. As before in the history of this field, the study of disorders, in this case genetic disorders, is a reasonable start. Identification of the genes and downstream events that lead to mental retardation and affective disorders will doubtlessly be invaluable in the diagnosis, treatment, and even prevention of human genetic disorders, with the desirable added effect of shedding light on the normal biology of behavior and cognition. There is a dearth of information about the participation of specific brain regions—and combinations thereof—in complex behaviors, which provides the opportunity for linking genes to behavior via the study of the brain. Thus, the brain represents the halfway point between genes and behaviors, and the first challenge is to understand how the brain is built from the functions of genes and their interactions with the early environment. At the same time, it is increasingly possible to link brain and behav-