[Morphologic characteristics of the RPDI neuron in the pond snail and its participation in the processing of multimodality sensory information].

The morphology of giant neuron RPDI in right parietal ganglia of Lymnaea stagnalis (Mollusca, Gastropoda) was studied by intracellular injection of the Lucifer Yellow. The branches of RPDI were found in nerves of right parietal, visceral, cerebral and pedal ganglia. Concentration of branches was revealed in visceral, right parietal and pleural ganglia. The branches of RPDI were observed also along peripheral nerves. Responses of the neuron to the adequate stimulation of various sensory structures (tentacles, lips, mantle, etc.) were studied by electrophysiological methods. It was shown that RPDI had a wide polymodal sensory input and responded to the adequate stimulation of mechano-, chemo- and photoreceptors in the head skin and mantle. Applied stimuli caused either subthreshold EPSP or spike response in the neuron. Neuron responses of the neuron conditions of chemical synapses blockade are discussed.