ABSTRACT
Disturbances of nervous system monoamine activity are thought to play a role in various psychiatric and neurological disorders of depression, anxiety, panic, phobia pain, and seizure. In particular, glutamate and serotonin (5-HT) play a significant role in the maintenance of neuronal functioning in two important ways. These monoamine neurotransmitters can alter postsynaptic flux, resulting in excessive depolarizations. This would be termed an ionotropic effect. These neurotransmitters can also affect the secondary-messenger system, resulting in the production of transcription factors that can cause or block neuronal gene expression (Wong et al., 1995). Glutamate and serotonin act on specific receptors located throughout the nervous system and other organ systems, including heart, gut, and blood cells. Drugs that alter the receptor binding of glutamate and serotonin may play a significant role in the management of acute and chronic pain syndromes, which are often accompanied by prominent behavioral features of panic, anxiety, depression, and sleep disturbance. This chapter will explore the role of the antiglutamate effects of ketamine, memantine, dextromethorphan, and CPP as well as the serotonergic effects of mCPP. Modulation of these two monoamine pathways may be useful in helping to dampen neuronal hyperexcitability, a desirable goal in the treatment of many neurological ills.
