Comparative electrophysiological aspects of aluminum actions on central neurons and neuronal synapses of invertebrate and vertebrate animals.

Aluminum compounds (Al) increased the membrane potential (Em) and decreased the input resistance (Rin) of identified snail neurons. The neuronal excitability increased after Al withdrawal in the washing period. Cumulative Al applications caused dose-dependent modulation of Em and Rin in most of the studied neurons. Two phase actions were recorded on stimulus evoked excitatory postsynaptic potentials (EPSPs) or currents (EPSCs) at pH 6.5-6.9. The Al induced facilitation followed by attenuation were statistically significant, time- and dose-dependent events. They could be recorded at each Em. Low affinity and slow binding kinetics could characterize the Al actions on the neurons. Al showed pH- dependent suppression of EPSPs or EPSCs in some neurons. Our findings are partially comparable with Al induced electrophysiological and pharmacological modifications reported on vertebrate neurons.