Fig. 9. Resetting the phase of swimming by stimulating sint2. (Top) An intracellular recording from Lsint2 during swimming; (bottom) a record of the animal's movements. The movement detector saturated and did not report the full range of side-to-side movement in this example. Hyperpolarizing current sufficient to silence the cell was applied via the recording electrode during the time indicated by the bar under the voltage recording. The time of maximal right flexion (shown by vertical lines above the behavior record) was measured during the 10 cycles preceding the onset of the stimulus in order to calculate the mean ± S.D. of the swimming period. These values were projected forward in time to predict the expected time of occurrence of maximal right flexion The bars and vertical lines above the behavioral record show the predicted time of occurrence of peak right flexion after the stimulus ends. Horizontal tics show the S.D. The difference between the predicted time of occurrence and the actual occurrence of peak flexion provides a measure of phase resetting. This experiment was repeated 15 times in three different whole animal preparations with consistent results.