Multipotentiality of the Brain to Be Revisited Repeatedly

The brain is a unified entity that cannot realize any functions in its isolated regions. It is also so dynamic that the functions of its regions and neurons are not necessarily fixed. Historically, this natural notion has been confirmed repeatedly by several experimental findings and theoretical considerations including those by Sherrington, Lashley, Hebb, Olds, and John. However, this notion, which typically can be called “multipotentiality” of the brain proposed by E. R. John, has been repeatedly ignored. Most studies in modern neuroscience are searching for fixed and peculiar regions responsible for individual, even any higher, functions and trying to detect treasured single neurons. This article emphasizes again the multipotentiality and raises promising strategies to investigate such unique features of the brain. First, we introduce the historical background and revisit the pioneering studies and consider the impacts of their views on our understanding of brain structures and functions. The second section emphasizes that the brain-machine interfaces has been presenting the multipotentiality of the brain’s regions and neurons. The third section considers the clinical relevance of the multipotentiality, particularly in relation to neurorehabilitation and the recovery of function after brain damage. Finally, we introduce recent neuroimaging findings indicating the multipotentiality and suggest an adequate experimental strategy to investigate the brain functions based on the view of multipotentiality, in which the assumption of cell-assembly coding is necessarily involved.