Delineating each addition to the 63 chapters covering new developments, techniques, and knowledge in neuroscience would require excessive space. Generally speaking, the progression of the chapters has remained the same, with relevant additions made to each to deal with new developments. Most of these additions, as already noted, fall into the molecular arena. A new chapter, "Genes and Behavior," is presented in part 1 and provides the foundation for genetic topics in subsequent chapters. The "Genes and Behavior" overview describes very cogently the multiple avenues for exploration of the genetic determinants of behavior, including single gene allele determinants of normal variations in behavior, as well as the effects of mutations, deletions, and other defects in manifest behaviors. This introduction does an exceptional job of setting the stage for the remainder of the text. The broad scope of this text is exemplified in the introduction as it overviews genetic findings in worms, Drosophila, and mice, bridging these findings with studies of complex behavioral and psychiatric disturbances such as bipolar affective disorder and schizophrenia.