The principle of coherence in multi-level brain information processing.

Synchronisation has become one of the major scientific tools to explain biological order at many levels of organisation. In systems neuroscience, synchronised subthreshold and suprathreshold oscillatory neuronal activity within and between distributed neuronal assemblies is acknowledged as a fundamental mode of neuronal information processing. Coherent neuronal oscillations correlate with all basic cognitive functions, mediate local and long-range neuronal communication and affect synaptic plasticity. However, it remains unclear how the very fast and complex changes of functional neuronal connectivity necessary for cognition, as mediated by dynamic patterns of neuronal synchrony, could be explained exclusively based on the well-established synaptic mechanisms. A growing body of research indicates that the intraneuronal matrix, composed of cytoskeletal elements and their binding proteins, structurally and functionally connects the synapses within a neuron, modulates neurotransmission and memory consolidation, and is hypothesised to be involved in signal integration via electric signalling due to its charged surface. Theoretical modelling, as well as emerging experimental evidence indicate that neuronal cytoskeleton supports highly cooperative energy transport and information processing based on molecular coherence. We suggest that long-range coherent dynamics within the intra- and extracellular filamentous matrices could establish dynamic ordered states, capable of rapid modulations of functional neuronal connectivity via their interactions with neuronal membranes and synapses. Coherence may thus represent a common denominator of neurophysiological and biophysical approaches to brain information processing, operating at multiple levels of neuronal organisation, from which cognition may emerge as its cardinal manifestation.

The role of coherence in a systems view of cancer development.

Theories of cancer origin are going through a paradigm shift, opening cancer research to new hypotheses. Accumulating evidence from the tissue microenvironment research, from bioenergetics, epigenetics, systems biology and thermodynamics tends to converge in characterising cancer as essentially a genetically non-deterministic disease. Instead, it is characterised by progressive disorganisation at a variety of organisational levels, from the genome and metabolic networks, to tissue integrity. As biological self-organisation is fuelled by the continuous supply of energy and infdrmation, these represent systemic roots of cancer origin, when compromised. The coherence of molecular dynamics has been recognised as an organising principle behind the long-range coordination of biological processes which can explain the remarkable efficiency of biological systems. Recent methodological advances have enabled the rapid accumulation of experimental evidence pointing to coherence as indeed playing an active role in mediating the flow of energy and information in diverse molecular systems, which is sufficient reason to apply it to a systems view on cancer development. We review theoretical models of how impaired coherence dynamics could lead to cancer as well as propose a new hypothesis based on the quantum electrodynamic theory of coherence. We discuss how the concept of coherence could connect different aspects of cancer and possibly represent their underlying theoretical framework, thus combining biological and physical approaches to understanding this complex pathology.

On the origin of cancer: can we ignore coherence?

A growing number of inconsistencies have accumulated within the genetically deterministic paradigm of the origin of cancer. Among them the most important are the nonspecific nature of cancer mutations and the non-cell-autonomous factors of cancer initiation and progression. Epigenetic aspects of cancer and cancer systems biology represent novel approaches to cancer aetiology and converge in the notion that cancer is characterized by a nonspecific progressive destabilization of multiple molecular pathways. The coherent behaviour of certain cellular subsystems has been theoretically predicted for a long time to have a general role in coordinating biological processes. However, it has only recently gained major scientific interest when it was measured on photosynthetic complexes at physiological temperatures and confirmed to have a direct effect over the dynamics of the energy transfer. Several theoretical and experimental considerations suggest that cancer might be associated with the absence or impairment of the proper coherent dynamics in certain biological structures, most notably in the microtubules. We review those models and suggest that impaired coherence might largely contribute to the progressive destabilization of the molecular and gene regulatory networks, thus connecting different non-genetic aspects of cancer.