I attach below the abstract of the article of Fisher.
The possibility that quantum processing with nuclear spins might be operative in the brain is proposed and then explored. Phosphorus is identified as the unique biological element with a nuclear spin that can serve as a qubit for such putative quantum processing – a neural qubit – while the phosphate ion is the only possible qubit-transporter. We identify the “Posner molecule”, Ca9(PO4)6, as the unique molecule that can protect the neural qubits on very long times and thereby serve as a (working) quantum-memory.
A central requirement for quantum-processing is quantum entanglement. It is argued that the enzyme catalyzed chemical reaction which breaks a pyrophosphate ion into two phosphate ions can quantum entangle pairs of qubits. Posner molecules, formed by binding such phosphate pairs with extracellular calcium ions, will inherit the nuclear spin entanglement. A mechanism for transporting Posner molecules into presynaptic neurons during a “kiss and run” exocytosis, which releases neurotransmitters into the synaptic cleft, is proposed. Quantum measurements can occur when a pair of Posner molecules chemically bind and subsequently melt, releasing a shower of intra-cellular calcium ions that can trigger further neurotransmitter release and enhance the probability of post-synaptic neuron firing. Multiple entangled Posner molecules, triggering non-local quantum correlations of neuron firing rates, would provide the key mechanism for neural quantum processing. Implications, both in vitro and in vivo, are briefly mentioned.
The starting point of Fisher was a very interesting finding challenging the hypothesis about life as mere bio-chemistry. Already in 1986, scientists at Cornell University examined the effects of the two isotopes of Lithium on the behavior of rats. Pregnant rats were separated into three groups. One group was given Li7, one group was given the isotope Li6, and the third served as the control group. Once the pups were born, the mother rats that received Li6 showed much stronger maternal behaviors, such as grooming, nursing and nest-building, than the rats in either the Li7 or control groups.
Li6 therefore as has a positive effect on maternal behaviour unlike Li7. The chemistry is exactly the same. According to the popular article, Fisher believes that the higher nuclear spin of Li6 could give it special role. As a matter fact, Li7 has higher nuclear spin of J=3/2 units whereas Li6 has nuclear spin J=1 so that the claim is not correct. Could the bosonic character of Li6 nucleus provide an alternative explanation? In any case, the finding strongly suggests that magnetic fields are involved.
Lithium – presumably Li6 – has also other positive effects. If the positive effects are indeed due to Li6 isotope, the dose of Lithium could be reduced by using only Li6 isotope. I attach here the abstract of the article that I wrote as a reaction to the discussions with my friend Samppa who told me about Lithium.
Lithium has been used for more than 50 years as a mood stabilizer in manic depression. During last years Lithium has been studied intensively and found that it can be used also in treatment of schizophrenia and many other brain disorders. The effectiveness of Lithium is however difficult to understand in the standard framework of biology. In TGD framework organism-environment pair of standard biology is replaced with the triplet magnetic body – organism -environment. Magnetic body uses biological body as sensory receptor and motor instrument. This suggests that the re-establishment of communications of brain with some level of the magnetic body is how lithium causes its positive effects. Magnetic body does not receive information about brain and cannot control it since dark Lithium ions and correspond- ing cyclotron radiation are not present. The disorders caused by the lack Lithium and other biologically important ions would therefore be something totally new from the perspective of standard neuroscience.
The TGD explanation for the effects of Lithium relies on the notions of magnetic body and dark large heff=n× h photons, electrons, and ions and relies on cyclotron frequencies as frequencies assignable to the dark photons responsible for the communications between magnetic body and biological body. In this picture the charge of the ion and its total magnetic moment would be relevant rather than only nuclear magnetic moment characterizing also neutral atoms (which could also contribute to the magnetic moment of ion). Cyclotron frequencies would replace Larmor frequencies.
Phosphate, Posner molecule, and cognition
Fisher as also other quantum biologists tries to understand quantum biology as an improvement of biochemistry. One assumes that standard quantum theory brings in small effects allowing to optimize biological functions. In the case of the avian navigation and also in many other situations the problem is that Earth's magnetic field is only 2 per cent of the minimum magnetic field at which the proposed radical-pair mechanism is found to work (see this). To my opinion much more radical approach challenging the basics of quantum theory itself is necessary.
Fisher assigns quantum entanglement with phosphate ion (see this). So called Posner molecule made of 6 phosphate ions and 9 calcium ions would be the key player. Fisher identifies the nuclear spin of so called Posner molecule as a biological qubit. Phosphate would be carrier of qubit giving rise to (working) quantum-memory.
In TGD framework both nuclear spins and angular moment of dark nuclei in the magnetic fields assignable to dark magnetic flux tubes would be important: Larmor frequencies would be replaced with the sums of Larmor – and cyclotron frequencies assignable to (usually) charged particles. It is interesting to look whether the cyclotron frequencies of phosphate and Posner molecule could teach something about their possible role.
These observations put the bells ringing – with a frequency of 10 Hz, one might say. Unfortunately this frequency is not directly audible, so that I cannot hope that colleagues would hear the ringing! There are however some hopes: also 10 Hz can be made audible as difference of frequencies fed to right and left ear! Maybe some experimentalist could get interested!
For a summary of earlier postings see Latest progress in TGD.