Abstract: After intramascular injection of strychnine, both the amplitude and the average duration of the PSPs induced in the M cell by stimulation of the vagus were increased. Two or more action potentials were superimposed on the PSPs. The results suggest that the intracellular depolarization probably comprises inhibitory components and the relation between the excitatory and inhibitory components perhaps modulates the excitability of the M cell, and thereby makes the response of the M cell in accordance with the activity of the whole body of the crucian carp.

Key words: Mauthner cell, vagus, strychnine, PSPs, crucian carp