Mixed synaptic modulation and inhibitory plasticity perform complementary roles in metastable transitions

Metastable transitions of neural populations have been tackled from deterministic chaos and stochastic neural noise (or fluctuations) perspectives, with a few research works investigating metastable transitions from the perspective of mixed synaptic modulation and inhibitory shortterm plasticity (ISTP). We explore what happens when synaptic weights are modified by electrical coupling and inhibitory plasticity in firing activities, and we provide three statistical analyses for capturing network activities and metastable transitions. We show that the mixed synaptic modulation and ISTP play different roles in metastable transitions of the excitatory networks. ISTP increases net inhibition for suppressing metastable states, giving rise to a straight-line phase transition between various firing modes. In contrast, electrical coupling significantly drives the line of this phase transition. The presented results bridge a few gaps in our understanding of the mechanism of coexisting firing patterns and the metastable transition when relevant parameters of synaptic strengths are varied.