Spectra of neurotransmitter receptors and ionic responses on cerebral A and B neurons in Aplysia californica.

Receptors to putative transmitters on A and B cells of Aplysia californica were identified and characterized. Neurons within each cluster were similar in responses to transmitters, but the neurons in A and B clusters differed. Both exhibited receptors to acetylcholine, dopamine, gamma-aminobutyric acid, glutamate, histamine and serotonin but not to octopamine or phenylethanolamine. Bi- or multiphasic responses to a single transmitter were common on both cell types. Inhibitory responses were more common on A than B cells where glutamate, histamine and serotonin were all excitatory. Each of these clusters appear homogeneous both in terms of presence of receptors and the ionic channels activated by the receptors.