Anesthetic Action and “Quantum Consciousness”: A Match Made in Olive Oil

Abstract

Anesthetic gases block consciousness selectively, sparing nonconscious brain activities, and thus their specific action could unravel the age-old mystery of how the brain generates, or mediates, consciousness. In this issue, Li et al.1 make a significant contribution to our understanding of both anesthesia and consciousness, showing that an isotope of the anesthetic xenon (129Xe) with the quantum property of nuclear spin 1/2 is significantly less potent than xenon isotopes without spin, despite identical chemical actions. Li et al. suggest that the xenon nuclear spin antagonizes its own anesthetic action by promoting consciousness, and that consciousness involves quantum brain processes, thus supporting a genre of theories known as “quantum consciousness.”“Quantum” implies the strange physics governing very small scales, but with large-scale implications via field effects, “nonlocal entanglement” (separated particles are somehow connected over space and time, in what Einstein called “spooky action at a distance”), coherence (multiple particles condense into unitary entities, governed by a wave function), and quantum superposition of multiple coexisting possibilities (used in quantum computing, with information as quantum bits, or “qubits,” of both 1 and 0 collapsing to either 1 or 0 as the solution).“Spin” is a particular quantum property related to angular momentum, or torque with a magnetic moment at discrete, quantized levels. Atoms with imbalances of protons and neutrons can have nuclear spin, and such particles (“fermions,” obeying the Pauli exclusion principle) have half integer quantized spin values: 1/2, 3/2, 5/2, and others. These spin states can entangle—be intimately connected with—other spin states, although separated in space and time. When one member of an entangled pair is perturbed, the other “feels it,” and responds immediately.“Quantum consciousness” theories suggest that entanglement, coherence, and quantum computing occur in the brain, offering potential solutions to challenges in cognitive neuroscience, e.g., the “binding problem.” In conscious vision, perceptual information for an object’s shape, color, motion, and meaning is processed at different times in different areas of visual cortex (V1, V2, V3, and so forth). Yet somehow, the disparate content is “bound together” in unified scenes, e.g., a red kite flapping in the wind. More generally, auditory, tactile, olfactory, and visual sensory modalities, along with memory and feelings, all apparently processed in different brain locations at different times, are also bound together, integrated, in unified conscious perceptions. (Indeed, Mashour2 has suggested “unbinding” as the key effect of anesthetic action.) Einstein’s “spooky action at a distance”—entanglement—may quite literally bind and integrate disparate brain content into unified conscious moments, like frames in a film or video. Sequences of such moments can give rise to our familiar stream of consciousness.In addition to nuclear spin entanglement, quantum dipole oscillations among π electron resonance clouds in membrane and cytoskeletal proteins have been implicated in consciousness, and are apparent targets of anesthetic action.3 Taken together, entanglement, coherence, and superposition from nuclear spin and electron cloud dipoles in critical brain proteins can account for (1) binding; (2) precise brain-wide synchrony; (3) ultrafast, massively parallel quantum computing (e.g., in microtubules); (4) anesthetic action; and (5) a link to fundamental aspects of the universe.4But quantum consciousness proposals have been dismissed and disregarded because technologic quantum computers are disrupted by thermal vibrations, and must operate near absolute zero temperature. Delicate quantum processes in the “warm, wet, and noisy”5 brain would surely “decohere”—be drowned out—by chaos in the aqueous biologic milieu. Or would they?Anesthesia to the rescue! In the nineteenth century, gases with diverse chemical structures were found to reversibly render humans and animals immobile, unresponsive and unconscious. Seeking a unifying factor, Hans Meyer (1899) and Charles Overton (1901) discovered that anesthetic potency correlated strongly with gas solubility in a nonpolar, “hydrophobic” lipid-like medium akin to olive oil. Potency is quantified by the ED50 (effective dose producing immobilization in half the population), which, for volatile anesthetics, came to be known as the minimum alveolar concentration. The solubility binding involves weak quantum dipole couplings (van der Waals London forces6) between electron outer shells of anesthetic molecules, and, e.g., “π electron resonance” clouds of aromatic amino acid rings inside certain brain proteins.The Meyer-Overton correlation thus defines an intraprotein, olive oil–like medium that is “quantum-friendly,” nonpolar, hydrophobic (not “wet”), and potentially suitable for quantum information processing relevant to consciousness. As for “war