Effect of α-tocopherol treatment on electrical activity CGCs. A. Examples of intracellular recording of spontaneous electrical activity in CGCs of control (CS-DS) and conditioned (CS-UCS) senior animals with supplementation of vehicle only (− αTocopherol) or with α-tocopherol (+ αTocopherol). B. Average number of spontaneous action potentials of CGCs in vehicle only and α-tocopherol treated conditioned and control animals. α-tocopherol caused an significant increase in the number of spontaneous action potentials recorded from CGCs compared with CGCs taken from vehicle treated animals. No significant effect was observed of conditioning on spontaneous electrical activity in both dietary treatments. C. CGC resting membrane potential of α-tocopherol treated snails was significantly more depolarized compared with vehicle only treated animals. Behavioural conditioning had no effect on resting membrane potential in both treatments. * = p < 0.05, ** = p < 0.01, *** = p < 0.001, ns = non-significant.