THE latest issue of Technology Review contains a photo essay by yours truly, called Time Travel Through the Brain, in which I look at how techniques used to investigate the brain have evolved during the 100 year history of modern neuroscience. The essay begins with a drawing by the great Spanish neuroanatomist Santiago Ramón y Cajal, who used the staining method discovered by Camillo Golgi to establish that nervous tissue is composed of cells, then goes on to describe more recent methods such as fibre tracing, Brainbow and various types of microscopy.
This image from the piece graced the cover of the Journal of Neuroscience back in April. It’s a rotary shadow electron micrograph showing the cytoskeleton of a hippocampal neuron, by Bernd Knöll of the University of Tübingen and Jürgen Berger and Heinz Schwarz of the Max Planck Institute for Developmental Biology. The technique involves freezing the specimen under high pressure in liquid nitrogen, then fracturing it with a blade in an ultra-cooled vacuum chamber to strip off the membrane. During fracture, the specimen stage rotates; as it does so, platinum and carbon are deposited onto it from a pair of electrodes, to produce a metallic three-dimensional replica of the cell interior.