Anesthetic action links consciousness to quantum vibrations in brain microtubules
Stuart Hameroff, M.D.
Professor, Anesthesiology and Psychology
Director, Center for Consciousness Studies
Banner-University Medical Center, The University of Arizona, Tucson, Arizona
Anesthetic gases selectively block consciousness, sparing non-conscious brain activities, and thus their mechanism of action could reveal how the brain produces, or mediates, consciousness. Anesthetic gas potency correlates with solubility in non-polar brain regions, recognized as 'pi resonance' electron clouds of aromatic amino acid rings in critical brain proteins. They bind therein by weak, quantum-level van der Waals 'dipole dispersion' London forces. In which brain proteins do anesthetics act to selectively block consciousness? Neuronal membrane receptor and ion channel proteins were long-assumed to be anesthetic targets, but experiments failed to support this contention, and genomic, proteomic and optogenetic evidence now point instead to anesthetic action in cytoskeletal microtubules inside neurons, polymers of the protein tubulin. Microtubules organize neuronal interiors, regulate synapses, and have experimentally-observed resonance vibrations in terahertz, gigahertz, megahertz and kilohertz frequencies. These are apparently mediated by electron cloud quantum dipole oscillations (suggested in Penrose-Hameroff 'Orch OR' theory to mediate consciousness).
To test relevance of microtubule quantum vibrations to consciousness, in Craddock et al (Scientific Reports 2017; 7:9877 doi:10.1038/s41598-017-09992-7) we used computer modeling and quantum chemistry to simulate collective quantum dipole oscillations among pi resonance clouds of all 86 aromatic rings in tubulin in their known positions. We then re-simulated the tubulin oscillations with each of 8 anesthetic gases, and 2 'non-anesthetic' gases (which bind in the same pi resonance regions but do not cause anesthesia).
Tubulin pi resonance collective vibrations showed a prominent common mode peak at 613 terahertz (blue light spectrum, but internal without photoexcitation). We found that all 8 anesthetics abolished and shifted the 613 terahertz oscillations proportional to their potency, and that non-anesthetics had no effect on the 613 THz peak.
Consciousness operates in a multi-scale hierarchical cascade, originating in terahertz quantum dipole oscillations in tubulin pi resonance clouds in microtubules, resonating upward in structural size, slowing in frequency through gigahertz, megahertz, kilohertz and hertz frequency ranges (EEG arising from 'interference beats'). Anesthetics dampen the quantum oscillations, slowing cascade resonance and preventing consciousness. The brain may be more like a quantum orchestra than a classical computer.