Static magnetic fields can diminish neuron spines through microtubule dynamicity disruption

Abstract

Recently, the hypothesis in which memory and information would be stored as magnetic forms in astrocytes is expanding and neuromagnetic interactions between neurons and neighboring astrocytes in neocortex have potential to be the basis of memory formation. It was proposed that any kinds of information could be maintained as the form of neuronal activity-associated magnetic fields (NAAMFs) and thereby alterations of magnetic fields in the brain should be effective on the memory. On the other hand, microtubules (MTs), the most essential elements of cytoskeleton, are crucial in regulation of spine development and morphology, brain cognitive behavior, consciousness and information storage. Because of MT dynamic nature, it can produce local magnetic field in neurons through vibration. According to size, number, structure and function of microtubule proteins, they are the most eligible components of neurons to be affected by endogenous and exogenous magnetic fields. Therefore, in the present study we tried to investigate the possible effects of exogenous static magnetic fields (SMFs) on memory through examining the structural and functional changes in MT dynamic activity and neural cell morphology. MT activity results revealed that MT polymerization process was not attained to steady state at the right time in the presence of SMF at 300 MT and the ascending slope at the steady state phase was abnormally observed. In addition, MT structure was relatively changed. On the influence of SMF, PC12 neuron-like cells spines decreased significantly and their morphology altered to pyramidal form.