We propose that thermally assisted proton tunneling in presynaptic enzymes contributes measurably to synaptic variability, producing a kinetic isotope effect (KIE) distinguishable from classical thermal noise. H→D isotope substitution in neuronal cultures should reduce the interspike interval coefficient of variation (ISI CV) by a KIE_network factor in the range of 1.5–3.5×, with a modal estimate of ~2.5×, under conditions where pure thermal noise predicts KIE ≈ 1. The prediction rests on: (1) documented proton tunneling in enzymes with KIE up to 100×; (2) a PCET-mediated vesicular fusion model; and (3) experimental evidence that heavy water modulates hippocampal synaptic transmission. The hypothesis does not require macroscopic quantum coherence or novel physics. The falsification threshold is explicit: KIE_red < 1.5× under controlled conditions with sufficient statistical power would refute the hypothesis in its current formulation.
We propose that thermally assisted proton tunneling in presynaptic enzymes contributes measurably to synaptic variability, producing a kinetic isotope effect (KIE) distinguishable from classical thermal noise. H→D isotope substitution in neuronal cultures should reduce the interspike interval coefficient of variation (ISI CV) by a KIE_network factor in the range of 1.5–3.5×, with a modal estimate of ~2.5×, under conditions where pure thermal noise predicts KIE ≈ 1. The prediction rests on: (1) documented proton tunneling in enzymes with KIE up to 100×; (2) a PCET-mediated vesicular fusion model; and (3) experimental evidence that heavy water modulates hippocampal synaptic transmission. The hypothesis does not require macroscopic quantum coherence or novel physics. The falsification threshold is explicit: KIE_red < 1.5× under controlled conditions with sufficient statistical power would refute the hypothesis in its current formulation.
We propose that proton quantum tunneling in presynaptic enzymes constitutes a source of genuine synaptic variability, qualitatively distinct from classical thermal noise and detectable via the kinetic isotope effect (KIE). The central prediction is that H→D isotopic substitution in neuronal cultures should reduce the coefficient of variation of interspike intervals (CV of ISI) by a factor KIE_net in the range 1.5–3.5×, derived from a quantitative three-scale model (molecular → vesicular → network). The prediction rests on documented proton tunneling in enzymes (KIE up to 100×), a PCET-mediated vesicle fusion model, and experimental evidence that heavy water modulates hippocampal synaptic transmission. The hypothesis requires no macroscopic quantum coherence or new physics. The falsification threshold is explicit: KIE_net < 1.5× under controlled conditions with adequate statistical power (N ≥ 15 per group, α = 0.0125) refutes the hypothesis in its current formulation. The protocol includes explicit controls for osmotic, viscous, and thermal confounds of heavy water.
La Hipótesis del Filtro Cuántico-Neurocrítico (HFQNC) propone un mecanismo integrador para la conciencia articulado en tres niveles de procesamiento: [Q<->F]->A. El Nivel Q describe fluctuaciones cuanticas documentadas en sinapsis (tunel protonico en enzimas sinapticas, pares radicales electronicos, criptocromos, moleculas de Posner y tunel ionico de litio) que generan variabilidad genuina como recurso funcional. El Nivel F describe el filtrado de esa variabilidad por decoherencia selectiva en un entorno estructurado por historia tripartita H(t) = H_evo + H_cult + H_pers. El Nivel A describe la amplificacion selectiva en redes neurales operando cerca de la criticalidad (exponente sigma aprox. 1.0), determinando el acceso consciente. La inversion conceptual central: la decoherencia no es el enemigo del efecto cuantico sino su mecanismo de traduccion funcional. La mielina, clasicamente concebida como acelerador de conduccion, cumple un rol adicional y original: estructura el entorno de decoherencia que define que variabilidad cuantica sinaptica se traduce en experiencia consciente. El marco ofrece predicciones cuantitativas falsificables: sustitucion isotopica H->D debe reducir la variabilidad sinaptica en factor KIE_red en el rango 1.5-3.5x; correlacion r < -0.5 entre mielinizacion e intensidad de percepcion magica infantil; vigilia normal sigma aprox. 0.98-1.02, anestesia profunda sigma < 0.85. Trabajo relacionado: Collados, J. (2026b). Modulacion isotopica de la criticidad neuronal. DOI: 10.5281/zenodo.18870856. Collados, J. (2026c). Tunel cuantico en enzimas sinapticas. DOI: 10.5281/zenodo.20026348
The kinetic isotope effect (KIE) is the conventional probe for quantum tunneling, yet its composite nature conflates tunneling with zero-point energy and classical kinetics. Here, we introduce the tunneling phase diagram, a machine-learning framework that decouples true tunneling strength by decoding the nonlinear relationship between KIE and the tunneling factor (\k{appa}). With exceptional fidelity (R^2 > 0.98, RMSE = 0.21), this framework reveals an anomalous high KIE-low \k{appa} spanning 300-600 K, thereby defining a paradigm for the quantitative assessment of quantum tunneling.
A study published on bioRxiv demonstrated that quantum tunneling plays a key role in in vitro hydrolytic enzyme reactions by analyzing kinetic isotope effects (KIE) through deuterium substitution. The involvement of the quantum tunneling effect was confirmed through temperature dependence experiments in major biochemical reactions such as SIRT3-mediated deacetylation, I-SceI-mediated DNA cleavage, and caspase-3-mediated protein cleavage. By observing that DNA homologous recombinational (HR) repair in living cells is almost completely inhibited in a deuterium environment that lowers the probability of quantum tunneling, it was demonstrated that quantum effects dominate cell survival itself. [Quantum Biology Society] Behind life phenomena lies a strange quantum world that cannot be explained by classical mechanics. A prime example is quantum tunneling, where particles pass through reaction energy barriers as if by magic. While it has been known that quantum tunneling contributes to speeding up some enzyme reactions inside proteins , there has been a lack of concrete empirical evidence as to whether this is an essential physical requirement directly linked to actual cell survival. Recently, a groundbreaking study was published showing that if the quantum tunneling effect is inhibited, the cell's life support system itself completely halts. The paper titled "Cell viability is dominated by quantum effects," published on the preprint repository bioRxiv, strongly supports this. A multi-institutional joint research team, including Takeshi Yasuda from the National Institutes for Quantum and Radiological Sciences and Technology (QST) and Kobe University in Japan, led this innovative research. ■ The Link Between Enzyme Hydrolysis and Quantum Tunneling The research team utilized deuterium, an isotope of hydrogen, to track how quantum tunneling is involved in enzymatic chemical reactions. In a heavy deuterium environment, the probability of quantum tunneling is significantly lower compared to light hydrogen, and the research team precisely measured the resulting kinetic isotope effects (KIE) and their temperature dependence. Experimental results proved that the quantum tunneling effect is deeply involved in in vitro hydrolysis reactions essential for cellular metabolism, such as SIRT3-mediated deacetylation, I-SceI-mediated DNA cleavage, and caspase-3-mediated protein cleavage, as evidenced by the disappearance of the isotope effect above specific temperatures. ■ A Halted DNA Repair System Furthermore, the research team directly investigated the impact of the quantum characteristics of these enzyme reactions on living cells. When human cells were exposed to a deuterium-substituted (D₂O) medium environment that artificially lowered the probability of quantum tunneling, it was observed that DNA homologous recombinational (HR) repair, one of the core survival mechanisms of cells, was almost completely inhibited. This means that the most important biochemical repair process protecting and maintaining the genetic information of organisms undergoes a chain reaction of several enzymes and cannot function normally without quantum tunneling phenomena. ■ Quantum Effects Dominating Cell Viability This study empirically demonstrates that core biochemical reactions in living organisms do not simply rely on thermodynamic energy but are fundamentally indebted to quantum mechanical tunneling phenomena. The discovery that numerous hydrolysis and repair reactions performed by enzymes within cells are ultimately strictly dominated by quantum effects serves as crucial evidence that rewrites life phenomena from a purely quantum physics perspective. https://www.biorxiv.org/content/10.1101/2023.07.18.549596v1
We propose a testable hypothesis linking quantum coherence in neural microtubules to gamma-band oscillations (30-100 Hz) observed in neural networks. Building on recent experimental evidence of electromagnetic oscillations in microtubule bundles and quantum super radiance in tryptophan networks, we hypothesize that microtubule quantum dynamics may influence the temporal precision of established gamma-generating mechanisms rather than serve as primary oscillation generators. Our empirically-grounded model incorporates measured microtubule electromagnetic properties and realistic decoherence calculations to predict specific correlations between microtubule coherence states and gamma oscillation timing precision. We present detailed decoherence analysis showing that while individual tubulin coherence is limited to femtosecond timescales under physiological conditions, recent experimental evidence suggests collective electromagnetic effects across microtubule networks might create mesoscopic domains with enhanced stability. The framework provides concrete experimental pathways using nitrogen-vacancy center quantum sensing combined with high-resolution neurophysiology to test quantitative predictions about quantum-classical coupling strengths. Key predictions include measurable correlations between microtubule electromagnetic activity and gamma timing precision (correlation coefficient r > 0.3), specific temperature dependencies matching quantum decoherence theory (characteristic temperature Tc= 12 ± 3 K), and selective pharmacological effects of microtubule-targeting drugs on neural timing precision while preserving oscillation power. These predictions distinguish our framework from classical models and provide clear falsification criteria for experimental validation.
Tunnel amplitudes of molecular configurations (like neuronal channel pores) may be very sensitive to thermal vibrations of the barrier width (vibration-assisted tunneling) resulting in pseudo-random spikes of widely varying sizes. An observer who ``lives'' behind the barrier would experience as an ``event'' an accidental minimum of the barrier width, the timing being determined by the microstate of the neuron's heat bath. In two neurons, set to detect a ``left'' or ``right'' state of an object, firing amplitudes typically differ so much as to produce a quasi-selection of one option.