Given the possible dynamic existence of axial forms of prototypic ischemic events involving neurons, one might consider the specific concept of selective vulnerability of such neurons to ischemia as a phenomenon arising directly from biologic as well as selective developmental parameters.  Indeed, one might consider specific neuronal subsets as simply a characterization, to variable degree, of biologic processes with relevance also to developmental mechanisms in determining ischemia as a pathway of progression or nonprogression.  Such a concept of biologic and developmental determination in terms of degree of neuronal susceptibility to ischemia might actually constitute a single axial system that permits possible neuronal recoverability in the context of an induced neuronal injury.  Indeed, one might relate defective biologic and developmental recoverability to specific enzymatic systems such as cytochrome C oxidase deficiency arising in a context of either a "normal" or "dysfunctional" neuronal adaptability.