Neurobiology of prenatal cocaine exposure effect on developing monoamine systems

Cocaine and crack belong to a broad category of agents that act primarily as central nervous system stimulants at the level of the monoaminergic neurotransmitter system (dopamine, norepinephrine, and serotonin). These neurotransmitters are involved in the regulation of a number of basic psychological functions including attention and arousal and play a crucial role in the defining of brain structure and neuronal formation. This paper outlines what is currently known about the direct effects of cocaine on the mature and developing central nervous system. Three general points are reviewed: (1) Cocaine has differing effects on structural and functional brain development throughout gestation (e.g., there is not a single, all or none effect); (2) No one area of the brain is singularly affected. Areas related by the monoaminergic system are differentially influenced and affecting one area may result in a functional change in another; and (3) Because substantial brain growth, synaptic formation, and remodeling occur in the first months after birth, ongoing postnatal exposure to cocaine also carries risk for direct effects on brain function. Understanding the developmental neurobiological effects of cocaine provides data to guide studies in infants and young children of how prenatal cocaine exposure may contribute to specific, biologically based areas of neurological vulnerability that will be expressed behaviorally and developmentally in the first 3 to 5 years of life.