Role of inhibitory neurons in temporal correlations of critical and supercritical spontaneous activity

Abstract

Experimental and numerical results suggest that the brain can be viewed as a system acting close to a critical point, as confirmed by scale-free distributions of relevant quantities in a variety of different systems and models. Less attention has received the investigation of the temporal correlation functions in brain activity in different, healthy and pathological, conditions. Here we perform this analysis by means of a model with short and long-term plasticity which implements the novel feature of different recovery rates for excitatory and inhibitory neurons, found experimentally. We evidence the important role played by inhibitory neurons in the supercritical state: We detect an unexpected oscillatory behaviour of the correlation decay, whose frequency depends on the fraction of inhibitory neurons and their connectivity degree. This behaviour can be rationalized by the observation that bursts in activity become more frequent and with a smaller amplitude as inhibition becomes more relevant.

15 pages, 6 figures

References in corpus (6)

• Scale-free brain functional networks
• Dynamical synapses causing self-organized criticality in neural networks
• Self-Organized Criticality model for Brain Plasticity
• Balance of excitation and inhibition determines 1/f power spectrum in neuronal networks
• Synaptic balance due to homeostatically self-organized quasicritical dynamics
• Predicting brain evoked response to external stimuli from temporal correlations of spontaneous activity

Cited by in corpus (2)

• Fluctuation-Dissipation Relations in the imbalanced Wilson-Cowan model
• On the scaling of avalanche shape and activity power spectrum in neuronal networks