Another modality of granule cell response, largely investigated in the vestibulo-cerebellum, is to generate spike trains in response to prolonged mossy fiber inputs (Arenz et al., 2008). When such stimuli were used, the PC model followed the input frequency (Figure 4B, left), although the frequency dependence was rather weak (as also noted for the BPR in Figure 4A). However, there was a steep relationship between the output frequency and the number of active synapses (Figure 4B, right). Therefore, the PC model was more efficient in detecting the intensity of the granule cell input rather than the frequency at individual synapses.