Figure 9

A simpler model can exhibit similar behavior to that of the FS-SI network. (a) Network schematic. The SI cell and input-1 are identical to the ones in Fig. 5(a). Input-2 is now inhibitory: the synapse from input-2 onto SI has the dynamics of the FS→SI synapse of the network in Fig. 5(a). (b) A simulation of the network in (a). Input frequencies are the same as in Fig. 5(b). The SI cell behaves as in Fig. 5(b), firing in phase with input-1, alternately with input-2. (c) Probability of the SI cell firing immediately after an input-1 pulse, as a function of the input-2 phase (time from last input-2 pulse). As in Fig. 7(a), the SI cell fires immediately after an input-1 pulse, if and only if the time since the last input-2 pulse lies in an interval of length 25 ms. (d) Firing rate of the SI cell as a function of the input-2 frequency. As in Fig. 6, the cell’s frequency follows that of input-2, for a range of frequencies. Small quantitative differences with the FS-SI network are due to differences in the spike form of input-2 compared to the FS cell, and to the lack of the excitatory synapse from input-2. Dashed line in (d): diagonal