Structural properties of network attractor associated with neuronal dynamics transition

It was found that single neuronal activities in various regions in the brain commonly exhibit the distinct dynamics transition from the white to the a/f spectral profiles during the sleep cycle in cats. The dynamics transition was simulated by using a symmetrically connected neural network model including a globally applied inhibitory input. The structure of the network attractor was suggested to vary in association with the change in inhibitory level. To examine the robustness of the dynamics transition, the symmetry network structure is extended to the asymmetrically connected network model. This asymmetricity follows the rule which approximately reflects the characteristics of synaptic contacts between neurons. Computer simulations showed that the inhibitory input could change the neuronal dynamics from the white to the 1/f profiles under more realistic situations. The geometry of the network attractor realizing the dynamics transition is discussed