Selective involvement of serotonin receptors in mechanisms of synaptic facilitation in neurons of a sensitized snails

In previous studies we found that the development of nociceptive sensitization in grape snails or serotonin application on the central nervous system was accompanied by a long-term facilitation of the responses of the defensive behavior interneuron Lpl1 and Ppl1 to sensory stimuli, which depended on translation and transcription processes. In the present work, the possibility of selective involvement of 5-HT1A serotonin receptors subtypes in the mechanisms of synaptic facilitation induction has been studied. It was found that the development of sensitization in the conditions of application to the neurons of these receptors antagonist NAN-190 (1- (2-methoxiphenil) -4- [4-(2phthalimido) butyl] piperasine hydrobromide) caused suppression of synaptic facilitation in the responses of Lpl1 neuron to tactile stimulation of snails head. In this case, synaptic facilitation in responses to chemical stimulation of the head and tactile stimulation of snail's leg developed in the same way as in the neurons of control sensitized animals. It is suggested that in sensitized snails, 5-HT1A-like receptors are selectively involved in the mechanisms of induction of plasticity of the defensive behavior interneurons synaptic "inputs" mediating excitations from the head mechanoreceptors.