Fig. 8. Firing pattern in swim interneuron 2 (sint2). (A) Activity in Lsint2 during a brief episode of behavior. Swimming was initiated by removing a surface from the animal's foot at the first arrow and terminated by replacing the surface at the second arrow. (B) Action potential bursts in Lsint2 shown at higher gain and on an expanded time scale. (C) Alternating bursts in the two antagonistic sint2 neurons recorded simultaneously during a long episode of swimming.