[The effect of cadmium ions on synaptic transmission in the tectum of the frog].

The effect of cadmium ions on the synaptic transmission in the frog tectum was analyzed in acute experiments by the method of recording of the quantum of EEG (the extracellular monosynaptic potential of synapses of a single axon) [1]. It was shown that perfusion of the tectum with CdCl2 in the concentration of 10-200 mumol/l reversibly inhibited the quanta of EEG, decreased their duration and increased the synaptic delay. Consequently, cadmium in industrial waste may be dangerous regarding the harm to the CNS, too. The results of the presented work correspond to the supposition based on experiments in vitro that presynaptic potential-dependent calcium channels prove to be one of the areas of synaptic action of Cd++ ions.