could toxins biological effects lead to criminal behavior?
Masters et al. say studies show that toxins can affect both the structure of the developing brain, and the function of neurotransmitters-the brain’s “messenger” chemicals. “Of particular importance,” they say, “may be synergistic interactions between elements whose toxicity is greatly multiplied when they are combined.” Among the many proven neurotoxic effects of heavy metals: • Excess lead in the brain damages cells called glia, which help detoxify harmful substances and are critical in behavioral inhibition. • Excess copper in the neonatal brain is associated with abnormal development of the hippocampus, a brain structure that plays a critical role in learning. • Excess manganese reduces brain levels of the neurotransmitters serotonin and dopamine, while increasing serotonin concentrations elsewhere in the body. Both human and animal studies link low brain serotonin to impulsive violence, and altered dopamine levels are implicated in a wide range of aberrant behavior. 4. TRANSMISSION
