The Widening Gyrus
Concert pianists could be model organisms for studying the physiological basis of intellectual greatness
Circulation in the Brain
The neuropathologist Alfred Meyer referred in a footnote to a work from 50 years before by B. K. Hindze of Moscow, “who had shown that in brains of persons of outstanding ability the arterial supply is more elaborate than in brains from persons of mediocre ability.” But this study was “too small to permit definitive conclusions.” In 1974 a report described blood flow in the brains of patients with chronic schizophrenia, and another report examined blood flow in normal persons in the hemisphere associated with speech and reading. Both studies used the Xenon-133 method with 32 detectors placed alongside the patient’s head. In the latter report the authors stated, “The blood flow of the brain is ultimately regulated by the metabolic activity of the neuronal tissue.” A 2008 paper by Fred Wolf and Frank Kirchhoff measured blood flow by fMRI and asserted that “astrocyte activity affects local blood flow.” Not reported in these studies is whether increased blood flow occurred via existing capillaries or newly formed ones—the latter arising perhaps in a process analogous to tumor angiogenesis. A reciprocal consideration is whether increased blood flow in an area might stimulate further neuronal or astrocyte development there, just as, in certain solid tumors, increased blood flow allows proliferation of malignant cells.
Michael Chopp and colleagues have recently examined agents that promote neurogenesis and angiogenesis during recovery from strokes induced in animals: “Matrix metalloproteinases expressed in the periinfarct vasculature are chemotactic for neuroblasts migrating from the subventricular zone.” Here angiogenesis was monitored by MRI.