Effects of Toxic Metals on Neurotransmitters

The present chapter deals with the effects of toxic metals on neurotransmitter function. A priori, there are several reasons for wanting to investigate why, how, or if some aspect of neurotransmitter function has been affected by a metal or metal-containing compound. In some cases, the primary signs of intoxication may suggest that selected aspects of chemical neurotransmission have been affected. In other cases, such studies may be designed to determine if such changes have occurred, and if they can be used as a toxic endpoint. Finally, a metal (whether in organic or inorganic form) may in some cases provide a useful tool to study CNS mechanisms of general interest. This chapter will attempt to provide a broad review of how such studies can be approached, in the process highlighting specific approaches, and illustrating these with examples from the literature. It is obvious, however, that the explosion of the neurosciences during the last decade has made the notion of summarizing this field in a few dozen pages impossible. The fact that a review limited only to neurochemical effects of organic forms of toxic metals was a daunting task (Morell and Mailman, 1987) should make it clear that an exhaustive review or critique of the available literature is not possible in one chapter. What this chapter is designed to do is provide an overview of the neurochemical approaches often used for studies of metal and other toxicants, their strengths and limitations, and examples of data with various toxic metals.