Chemical impacts on higher brain functions

The central nervous system is highly sensitive to endogenous and exogenous chemicals. Catecholamines, norepinephrine (NE) and dopamine (DA), regulate many different brain functions including learning and memory, emotion, stress responses and homeostatic control of physiological systems. NE and DA are differently involved in reward-related neuronal activity and other task-related neuron activities in the prefrontal cortex, amygdala and the lateral hypothalamic area. During inflammatory and non-inflammatory stress conditions, NE levels are locally regulated at terminal levels by proinflammatory cytokines such as interleukin-1beta in which prostanoid and nitric oxide are involved. NE system has been shown to express estrogen receptors and is highly sensitive to endocrine disrupters such as bisphenol A during sexual differentiation. These findings suggest that higher brain functions such as learning and emotional control are under the influence of chemical impacts via catecholamines, cytokines and environmental chemicals. (C) 2004 Elsevier B.V. All rights reserved.