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Fig. 4. Excitatory junctional potentials of DEM1 and DEM2 following electrical
stimulation of nerve to deep extensor muscles (npm). Stimulation was gradually
increased from A to C and from D to F. Two experiments (AC and
DF) were performed in separate animals. (AC) Recordings were
taken simultaneously from neuron #1, DEM1) and N3. Junctional potentials in
DEM1 (middle trace in B) were not obtained at a stimulus intensity that
activated neuron #1, while a greater stimulus produced an excitatory
junctional potential (middle trace in C). (DF) Recordings were taken
simultaneously from neuron #1, DEM2 and N3. A given stimulus intensity caused
compound action potentials in N3 (bottom trace in E), but neither neuron #1
nor DEM2 are activated. However, a stimulus intensity that activates neuron #1
(top trace in F) brings about a junctional potential in DEM2 (middle trace in
F).