Prenatal effects of drugs of abuse on brain development.

Drugs of abuse modify signaling of neurotransmitter systems and intracellular messengers. Recent studies of central nervous system development show that these same neurotransmitters may serve as molecules that regulate specific aspects of cell proliferation, survival, migration, circuit formation and establishment of topography. Moreover, the convergence of neurotransmitter, growth factor and hormone activity on similar intracellular signaling systems suggests the potential for significant interactions among molecular components that regulate development. The application of modern strategies used by developmental and cell biologists to the question of whether prenatal drug exposure alters brain structure and function has led to discoveries of specific, targeted changes. Studies of the mechanisms of drug action that lead to altered neural development are now reality.