Molecular genetic approaches to mammalian brain and behavior: an introduction.

Two of the goals of behavior genetics have been to identify individual genes with effects on brain and behavior and to determine the mechanism(s) for effects of individual genes on brain and behavior. With classical genetics, this would have consisted of identifying a gene by mapping it to a chromosome and of determining the pathways for its effects, tracing back from behavior or brain to the gene. Molecular genetics brings other approaches to these issues. Findings with molecular methods also lead to hypotheses with regard to mechanisms for effects of individual genes on brain or behavior. In this issue examples of molecular genetic approaches are described for perceptual (color vision and olfaction), motivational (circadian rhythms and sexual behaviors), learning and memory, and pathological (alcohol-related and schizophrenia) aspects of mammalian behavior.