This is a fluorescently tagged primary visual cortex neuron from a light microscope capture of a brain slice preparation. These data were focus stacked revealing a tremendous amount of detail including the spines. Focus stacking is common method in confocal microscopy, but many folks do not realize that you can also do it with traditional light microscopy of just about anything using ImageJ or Adobe Photoshop. See here for an example and discussion of focus stacking.
This very cool study by Dorothy P. Schafer, Emily K. Lehrman, Amanda G. Kautzman, Ryuta Koyama, Alan R. Mardinly, Ryo Yamasaki, Richard M. Ransohoff, Michael E. Greenberg, Ben A. Barres and Beth Stevens demonstrates how the immune system can participate in the circuitry of the developing mouse lateral genicular nucleus (LGN).