Fig. 2. Electrical and contractile responses of muscle are temperature dependent. Intracellular and tension recordings from dactyl opener muscle in response to trains of stimuli delivered alternately to the inhibitory (OI) and excitatory (OE) motoneurons. The timing of the stimulus trains (12 Hz for 700 ms for the inhibitory motoneuron OI; 10 Hz for 500 ms for the excitatory motoneuron OE) is indicated above the traces. Intracellular recordings of muscle membrane potential are shown above the corresponding tension recordings, traces are averaged from ten stimulus trials at the indicated temperatures. Muscle resting potential was –56 mV at 2°C.