An in vivo correlate of exercise-induced neurogenesis in the adult dentate gyrus.

With continued debate over the functional significance of adult neurogenesis, identifying an in vivo correlate of neurogenesis has become an important goal. Here we rely on the coupling between neurogenesis and angiogenesis and test whether MRI measurements of cerebral blood volume (CBV) provide an imaging correlate of neurogenesis. First, we used an MRI approach to generate CBV maps over time in the hippocampal formation of exercising mice.

Technology Insight: imaging amyloid plaques in the living brain with positron emission tomography and MRI.

Alois Alzheimer first imaged amyloid plaques in 1906 by examining dead tissue under the microscope, but their clinical significance has remained undetermined. Now, nearly a century later, investigators are beginning to image amyloid plaques in living brains using both positron emission tomography and MRI. In this article, we review the studies that report on these recent technical advances, and discuss their potential importance in clarifying the diagnostic and pathogenic relevance of amyloid plaques to Alzheimer's disease.