Silant'eva D I, Andrianov V V, Gainutdinova T Kh, Gainutdinov Kh L, Pleshchinskii I N
Biophysics Laboratory, Kazan Physicotechnical Institute, Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia.
Neurosci Behav Physiol. 2006 Mar;36(3):209-12. doi: 10.1007/s11055-006-0001-4.
Studies of the electrical characteristics of the command neurons of a defensive reflex showed that the membrane potential showed no significant changes in response to changes in the calcium concentration in the perfusing solution in either intact or trained snails. Increases in the calcium ion concentration in intact snails were accompanied by increases in the threshold potential, from 14 +/- 0.7 mV at 2.5 mM Ca2+ to 21.8 +/- 0.9 mV at 20 mM Ca2+. The threshold potential in trained snails decreased in response to both increases and decreases in calcium concentrations, from 16.8 +/- 0.6 mV (physiological saline containing 10 mM Ca2+) to 13.3 +/- 0.6 mV at 20 mM Ca2+ and 11.8 +/- 0.8 mV at 2.5 mM Ca2+. The critical depolarization level changed correspondingly: in intact snails, this decreased with increases in calcium concentration, while in trained snails it increased in response to both increases and decreases in the calcium concentration.
