Abstract: In the present experiment, microelectrode was used to explore the physiological properties of the Mauthner cell with the stimuli of the skin.Direct stimulation of the skin evoked postsynaptic potentials (PSPs), which were stimulus strength-and frequency-dependent within some limits.The intracellular skin responses could be increased by passing hyperpolarizing currents to the M-cell through the Cl^- filled electrode.The results suggest that the afferent pathways from skin to M-cells contain both excited and inhibitory compotents, which interact each other and modulate the excitability of the M-cells together.

Key words: Mauthner cell, crucian carp, Cl^-, postsynaptic potentials