Dynamic information routing in neuronal networks of the brain

Post date: Oct 30, 2012 11:56:02 PM

Demian Battaglia - MPI for Dynamics and Self Organization

http://www.nld.ds.mpg.de/~demian

Flexible transmission of information is a core feature of many biological systems. The timing of the exchanged signals is decisive for the correct routing of information through complex interaction networks. A naturally-emerging mechanism which is fit to temporally coordinate the transmission of information might be oscillatory synchronization, which can arise whenever the intrinsic dynamics of network nodes undergo cyclical fluctuations. Sustained interest has been raised in particular by local to brain-wide synchronization of neural oscillations, due to growing experimental evidence for its function in perception, attention or inter-circuit coordination.

Here we investigate the role played by dynamic long-range synchronization in the flexible control of inter-areal causal influences in different "brain states", given that anatomic inter-areal connections can be considered as fixed, on timescales relevant for behavior. We show that, thanks to the nonlinear interaction between brain rhythms, even simple modular circuits involving few interconnected local circuits (or "brain areas") can originate a multitude of effective circuits associated with alternative functions selectable "on demand'". Precisely timed (endogeneous or exogenous) inputs can be used to induce reliably controlled switching between effective circuits.

We furthermore demonstrate that different effective circuits enact alternative modalities of information routing between nodes of the underlying fixed structural circuit. Interestingly, the spiking of individual neurons can be very irregular even when the collective rate oscillations are regular. We show then that the self-organization of interacting "analog" firing rate oscillations allows to flexibly route streams of "digital-like" information encoded in complex spiking patterns.

Reference: Battaglia D., Witt A., Wolf F., Geisel T. (2012) Dynamic effective connectivity of inter-areal brain circuits, PLoS Comp Bio 8(3):e1002438