Neurotoxin effects of Roth 801, dental sealer, on the spontaneous bioelectrical activity of F1 neuronal cells in Helix aspersa: using current-clamp technique

ABSTRACT

Some dental sealers have neurotoxic effects on neuronaltissues. These effects appear to be mediated through the inhibition of ionicchannels. Intracellular recording was performed on neuronal cells tocharacterize the underlying ionic mechanisms of neurotoxicity induced byRoth 801. Materials and Experiments were carried out on F1 neuronalsoma membrane located in the right parietal ganglion of snail, Helixaspersa. The properties of action potential were analyzed using singleelectrode current clamp method. Roth 801 was applied to the bathingsolution in invasive and gradual forms. In the current clamp experiments, several parameters, including,resting membrane potential [RMP], the peak amplitude of action potential,spike width, frequency, the peak amplitude of after hyperpolarization [AHP]were analyzed. In both invasive and gradual forms Roth 801 decreased thepeak of amplitude and frequency of action potential and the peakamplitude of AHP. But the duration of spike was prolonged. After invasiveapplication of Roth 801, membrane potential was depolarized. However ingradual method, it was initially hyperpolarized and subsequently shiftedtowards depolarized potential. These results suggest that Roth 801 affects shape andfrequency of action potential through inhibition of ionic currents