The duration of the storage of the electrical characteristics of command neurons in the acquisition of long-term sensitization in the snail

The retention of the long-term sensitization (LTS) of defensive reflex and dynamics of change in electric characteristics (membrane potential (Vm) and action potential generation threshold (Vt)) of command neurons of defensive reflex was studied in a snail during behavioral tests. The membrane mechanisms were analyzed by measuring electrical characteristics of the LPa3, RPa3, LPa2, and RPa2 command neurons on the 1st, 4th, 7th, 10th, and 14th days after the LTS formation and 1 month later. The membrane potential and threshold potential in sensitized snails (-54.1 +/- 2.0 and 24.5 +/- 1.4 microV, respectively) were significantly (p < 0.001) decreased in comparison with the control animals (-60.9 +/- 0.8 and 19.9 +/- 0.6 microV respectively). These changes retained within 14 days after the LTS formation. The results suggest the long-term retention of the increased excitability of command neurons. A month after the LTS formation, the duration of the defensive reflex returned to the initial level and the electric characteristics of command neurons did not significantly differ from the control (-61.1 +/- 2.0 and 19.3 +/- 1.4 microV, respectively).