Neurotransmission in the Auditory System: A Primer for Pharmacologists

Sensory processes have not been a traditional concern of pharmacologists. An occasional review article on the pharmacology of sensation has appeared but the pharmacological literature concerned with afferent or sensory sys­ tems is practically nonexistent. This, despite the fact that the information transfer in afferent or sensory systems apparently involves that favorite playground of the neuropharmacologist, the chemically-mediated synapse, as much as efferent systems do. There is an inertia in pharmacological thought which tends to produce continued interest and productivity in efferent and central systems but opposes efforts to move into nontraditional areas such as sensation. Pharmacologists, furthermore, are not trained to deal with sensory processes and so sensation has been out of the pharmaco­ logical mainstream. One result of this neglect is the fact that with the still arguable exceptions of substance P and adenosine triphosphate none of the primary afferent transmitters has been identified. In fact, as will be clear· later, some of the primary afferent transmitters may not belong to the universe of classical putative transmitters at all. Pharmacologists commonly say that drugs affecting nervous structures do so mainly by influencing processes associated with transmission. That is, that chemical transmission, as against conduction, is a particularly drug-