Li isotopes differentiation in neuronal activity – evidence for novel quantum effects in neuroscience*

 

It has recently been proposed that quantum effects, including nuclear spin effects, may be operational in the brain. In our work, we studied the role of the two stable isotopes of lithium (Li) to elicit a Li isotope differentiation in neuronal activity. While natural Lithium salts have been a frontline medication for the treatment of bipolar disorder (BD), the role of Li isotopes remains largely unexplored. In the past, two studies reported puzzling different effects of Li isotopes on animal behavior of rats. In addition, recent theoretical works have proposed that the two lithium isotopes could induce distinct neurological effects due to quantum effects arising from their distinct nuclear spin – but direct experimental evidence has been lacking.

Using multielectrode array (MEA) electrophysiology, we discovered that the two lithium isotopes have a very large and opposite effect on the electrical activity of rat hippocampus slices, affecting differently both synaptic transmission and synaptic plasticity. These results directly indicate that the two Li isotopes have different ways in affecting electrical neuronal activity in the brain, circumventing the less direct and possibly ambiguous evidence from the two aforementioned previous animal behavior studies. In addition, we tested several biochemical targets, such as GSK-3β kinase, actively scrutinized as a potential target for Li action; explored the effects of Li isotopes on cell viability in HT-22 neuronal cells and in mitochondria Ca exchange via the sodium-calcium-lithium exchanger (NCLX). No isotope differentiation was observed within these specific biochemical targets. The search for the molecular mechanisms continues, with the goal to uncover the quantum phenomena that can explain the large isotope differentiation effect observed in electrical activity of neuronal tissues.