Diversity beyond variance: modulation of firing rates and network coherence by GABAergic subpopulations.

摘要: Computational modelling studies have revealed that heterogeneity in interneuronal networks can powerfully modulate firing rates, responses to excitatory inputs, theta-gamma oscillations and network synchrony. In these previous studies, was represented by the degree of variance various synaptic cellular parameters. However, a major characteristic gamma-amino-butyric-acid-ergic (GABAergic) populations is presence distinct subgroups, which variance-based approaches cannot fully address. Here we apply an information theory-based measure diversity, Shannon-Wiener diversity index (equivalent entropy), takes into account both number relative abundance categories within population. data experimental dynamic clamp results show increasing somatically injected inhibitory post currents (IPSC) peak conductances modulates rates CA1 pyramidal cells predictable manner depends on mean IPSC conductance. Furthermore, increases strongly decreased coherence, even when population variance, previously applied heterogeneity, remained unchanged. These reveal new approach study demonstrate modulation principal cell coherence parameter clustering at levels.