Synchronization of Action Current Waves from Homologous Muscle Groups during Reflex Activity

By means of two perfectly matched, non-interfering, amplifying-recording units, action currents were recorded simultaneously from two homologous muscles during reflex response. A common stimulus was used to elicit the reflex. The homologous muscles studied were the gastrocnemius, the quadriceps femoris, and the masseter in the human being. In all homologous pairs of muscles studied the action currents were practically the same for each member of the pair with respect to frequency, intensity, and wave form. These results show that homologous muscles have a common integrating center in reflex activity, and that neither the motor nerve nor the muscle masses alter the discharge from this common integrating nerve level