Effect of protein synthesis inhibitors on neuronal mechanisms of sensitization inHelix snail

Abstract

A sensitizing treatment with 5–10% quinine solution causes short-term (lasting 50–70 min) and long-term (lasting several hours) changes in the activity of the command neurons for defensive behavior (LPl1 and PPl1) in the snailHelix lucorum. The short-term effects are characterized by a depolarizing shift in membrane potential, increased excitability, and an initial increase in the content of bound calcium (Ca-c) in the neurons. The long-term effects appear as facilitation of synaptic components of neuronal responses to sensory stimuli without any changes in excitability and in membrane potential, and also as a repeated increase of Ca-c content. Treatment with anisomycin or cycloheximide during sensitization acquirement prevents development of long-term sensitization.