Network anatomy and in vivo physiology of visual cortical neurons.

In the cerebral cortex, local circuits consist of many thousands of neurons, each of which makes thousands of synaptic connections in turn. Perhaps the biggest impediment to understanding these networks is that we have no wiring diagrams of their interconnections. Even if a partial or complete wiring diagram was available, understanding the network would also require information about each neuron’s function. Here the authors show that the relationship between structure and function can be studied in the cortex with a combination of in vivo physiology and network anatomy. Two-photon calcium imaging was used to characterize a functional property-the preferred stimulus orientation-of a group of neurons in the mouse primary visual cortex. Large-scale electron microscopy of serial thin sections was then used to trace a portion of these neurons’ local network. Consistent with a prediction from recent physiological experiments, inhibitory interneurons received convergent anatomical input from nearby excitatory neurons with a broad range of preferred orientations.
Bock DD et al., Nature 471: 177-182 (2011).
http://www.nature.com/nature/journal/v471/n7337/full/nature09802.html