Selective effect of the antibody to protein SMP-69 on activity of the defence behavior command neurons in grape snail

Effects of antibody against serotonin-modulated protein SMP-69 on defence behavior command neurons L-RP11 were studied in semi-intact preparation of snail Helix lucorum. An increase in membrane excitability as well as selective facilitation of neural responses evoked with chemical sensory stimulation of the snail head (0.25-0.5% quinine solution) were determined 1-1.5 hours after antibody application to the neurons. The antibody did not change neural responses evoked with tactile stimulation of the snail head. These effects were similar to those found in L-RP11 neurons after serotonin or cAMP applications as well as after nociceptive sensitization of the snail. It was suggested that protein homologically related the SMP-69 in mammalians was involved in mechanisms of excitability as well as long-term specific plasticity regulation of L-RP11 neurons synaptic inputs from the head chemoreceptors in snail Helix lucorum.