Whole-cell recordings from frog tectal slices revealed different types of neuronal firing patterns in response to prolonged current injection. The patterns included regular spiking without adaptation, accelerating firing, adapting spiking, repetitive bursting and phasic response with only one spike. The observed firing patterns are similar to those found in the mammalian superior colliculus. The frog tectum could be a useful preparation in elucidating the relationship between neuronal function and membrane properties.