Who were the primary developers of two-photon microscopy for visualizing brain activity? Following Watt Webb’s seminal work, it was Winfried Denk, David Tank, Karel Svoboda, and David Kleinfeld. What do these four have in common? They all worked at Bell Labs, and they all do imaging in rodent somatosensory cortex. Primary somatosensory cortex (SI), particularly barrel cortex has many advantages. You can directly observe the input (whisker touching), you can get behavioral output, the cortex is smooth, has a vivid characteristic pattern of cytochrome oxidase staining and is accessible to a cortical window. Consequently, SI is one of the best characterized regions of cortex. Far less understood is the structure and function of secondary somatosensory cortex (SII), but it likely plays an essential role in rodent sensory perception. For Journal Club #3, I review what is know of the location, structure, connectivity, physiology and function of SII.