The dentate gyrus network model shown here filtered a specific frequency of the periodic synaptic input through the perforant path. The filtering properties were modified by the degree of synchronization of the periodic perforant path input. The random synaptic input through the perforant path also contributed to the modification of the filtering properties. When the random synaptic input of the perforant path was delivered to several granule cells, adequately synchronized periodic perforant path input led to properties of a band-pass filter in the dentate gyrus network model. The bandwidth of the band-pass filter was 2 - 5 Hz. Without the random synaptic input, the dentate gyrus network model showed a property of a low-pass filter.