Electrogenic Effects of Neutral Amino Acids on Neurons of Aplysia Californica

Amino acids are commonly assayed in the search for new transmitter candidates. When, in this perspective, a variety of common amino acids were tested on neurons of the pleural ganglion of Aplysia californica, it was noted that monoamino monocarboxylic (so-called neutral) amino acids cause electrogenic effects that are not typical of responses to substances known to serve a transmitter function. This paper describes the response of Aplysia neurons to neutral amino acids, compares it to responses elicited by established transmitters, and discusses the possibility that the electrogenic effect caused by neutral amino acids reflects a sodium-coupled uptake of these amino acids in the Aplysia neurons.