The involvement of key factors operating independently or in cooperation with others contributes to physical and physiological mechanisms to help engineer a vertebrate hypothalamus. The actions of these key factors influence developmental mechanisms including neurogenesis, cell migration, cell differentiation, cell death, axon guidance, and synaptogenesis. On a molecular level, there are several ways to categorize the actions of factors that drive brain development. These range from the actions of transcription factors in cell nuclei that regulate the expression of developmental genes, to...