[Role of serine/threonine and tyrosine protein phosphatases in command Helix lucorum neurons at the cellular correlate of habituation].

Effects of some inhibitors of serine/threonine and tyrosine protein phosphatases on the depression and spontaneous recovery of the acetylcholine-induced inward current (ACh-current) in command Helix neurons of defensive behavior at the cellular correlate of habituation were investigated. The following drugs were used: okadaic acid (reduces activity ofphosphatases PP1 and PP2A), endothall (PP2A), cyclosporine A and cypermethrin (PP2B), CCT007093 (PPM1D), dephostatin (blocks tyrosine phosphatases). All used inhibitors modify the depression flow, and endothall reduces spontaneous recovery of ACh-current also. Obtained results indicate that changes in cholinosensitivity of command neurons depend on activity of all investigated protein phosphatases. Mathematical model considers the possibility of different localizations of receptors in a neuron and regularity of transitions between them. This model makes it possible to conclude participation indicated phosphatases in mobility of membrane cholinoreceptors ensuring the ACh-current modification at the cellular correlate of habituations. Comparison of experimental and calculated curves of ACh-current change allows to conclude that the main target of protein phosphatases is the transport system of a neuron--cytoskeleton and motor proteins.