Effect of movement on the cardiac conditional reflex

The cardiac component of the motor conditional reflex to a faradic stimulus to the hind leg in three dogs was measured. The leg was paralyzed by crushing 4 to 5 anterior roots of the lumbar nerves (second to sixth). The cardiac experiments were repeated beginning four days after operation and measurements were taken of the cardiac conditional reflex. A comparison of the increase in cardiac rate to the conditional stimulus before and after operating showed no significant difference in spite of the fact that the dog was unable to lift his leg to the stimulus. From this we conclude that the execution of the movement is not necessary for the increase of heart rate in the cardiac conditional reflex.