Persistent firing in the hybrid model can co-exist with theta rhythm.

<p>(A1 and 2) Responses of the pure network model to a 7 Hz sinusoidal current injection. The amplitude of the current injection was 0.12 nA in A1, and 0.13 nA in A2. (B1 and 2) Responses of the hybrid network model to the same current injection with an amplitude of 0.12 nA in B1, and 0.13 nA in B2. Theta entrainment was observed only in the hybrid model. (C) Frequency of persistent firing as a function of the amplitude of the sinusoidal current injection. In all figures, (i) Membrane potential, (ii) Intracellular calcium concentration, (iii) CAN current conductance, (iv) Current injection. I_CAN: CAN current.