Cholinoreceptor neurons of the snail: identification, plasticity, and its regulation by opioids and second messengers.

A review of the author's own data on the cholinoreceptors of identified neurons of the snail and the regulation of their plasticity. The following sections are presented: the identification of the cholinoreceptors; the coupling of the cholinoreceptors with ion channels; the identification of the opioid receptors; the modulation by opioids of the activity of the cholinoreceptors; the plasticity of the cholinoreceptors; the regulation of the plasticity of the cholinoreceptors by opioids; the regulation of the plasticity of the cholinoreceptors by second messengers; the second messengers involved in the regulation of the plasticity of the cholinoreceptors by the opiate kappa agonist, bremazocine.