The internal frequencies of chain network of FHN neurons include two different frequencies, namely, the intrinsic and Canard frequency. When the frequency of external stimuli approaches to the values of these two frequencies, signal processing in the chain will be enhanced. In traditional medical of Chinese acupuncture, signals evoked by different manipulations follow certain tracts to reach different target tissues. So it is reasonable to establish a chain network of FHN neurons to mimic the tract for frequency study.