Neuronal Specificity & Plasticity: from Sperry to the Blue Brain

This is a modest review of a couple of papers devoted to an examination of neural specificity and invariance among microcircuits in neocortical columns and minicolums, and the loci of experience dependent plasticity and learning within and between these microcircuits. It focuses on somatosensory cortex, but the appendix covers visual research as well on some of the early work on these issues, from Stratton, to Sperry, Hebb, Mountcastle, Hubel and Wiesel, and T. A. Woolsey and Van der Loos. It starts with a paper from Markram’s group on the invariant properties of the microcircuits, and conjectures on a segue form Hebb to Edleman’s Darwinian brain theories. Next I review Petersen’s paper on neurophysiological studies of experience dependent plasticity in these systems. Some network theory has proved essential to research in these areas, as well as some nifty technical advances in neurophysiological stimulation and recording.