Emergence and fragmentation of the alpha-band driven by neuronal network dynamics

by Lou Zonca, David Holcman Rhythmic neuronal network activity underlies brain oscillations. To investigate how connected neuronal networks contribute to the emergence of theα-band and to the regulation of Up and Down states, we study a model based on synaptic short-term depression-facilitation with afterhyperpolarization (AHP). We found that theα-band is generated by the network behavior near the attractor of the Up-state. Coupling inhibitory and excitatory networks by reciprocal connections leads to the emergence of a stableα-band during the Up states, as reflected in the spectrogram. To better characterize the emergence and stability of thalamocortical oscillations containingα andδ rhythms during anesthesia, we model the interaction of two excitatory networks with one inhibitory network, showing that this minimal topology underlies the generation of a persistentα-band in the neuronal voltage characterized by dominant Up over Down states. Finally, we show that the emergence of theα-band appears when external inputs are suppressed, while fragmentation occurs at small synaptic noise or with increasing inhibitory inputs. To conclude,α-oscillations could result from the synaptic dynamics of interacting excitatory neuronal networks with and without AHP, a principle that could apply to other rhythms.
Source: PLoS Computational Biology - Category: Biology Authors: Source Type: research