Invertebrate models for the study of the effects of age on neurotransmitter release

Invertebrate organisms have made important contributions to the study of aging by providing experimental evidence for the role of natural selection, genetic aging programs, and the existence of cellular circuits involved in the determination of life span. In addition, these models have made significant contributions to our understanding of the effects of age on the function of the nervous system. Although most studies have relied on complex behaviors as a proxy for neuronal function, a few studies have moved past the behavioral correlates and have applied modern electrophysiological and imaging techniques to study the effects of aging on neurotransmission at defined synapses. The synapse is the substrate on which behavior is controlled, but our understanding of how aging alters synapse function is poorly understood. In this chapter we review two invertebrate synapse models that provide important insight into how aging alters neurotransmission. These systems provide important hypotheses for how aging could directly affect synapse function resulting in the deterioration of nervous system function.