The Edwin Smith Surgical Papyrus (page 369 in this issue) dates back nearly four millennia and contains the first written example of the word 'brain', as well as the earliest known descriptions of the meninges and the cerebrospinal fluid. The papyrus, which now belongs to the New York Academy of Sciences, is structured as a series of cases that include the first accounts of several forms of brain injury and their associated consequences. One fascinating aspect of the papyrus is that the author did not resort to magical explanations when discussing the cases, but took instead a more analytical view and attempted to provide a rational approach to their treatment. In fact, the author classified each case as favourable, uncertain or intractable, depending on its prognosis. So, for example, the Edwin Smith Surgical Papyrus classified hemiplegia and quadriplegia as intractable conditions, a status that, sadly, has not changed substantially since.

Although significant progress has been made in the search for a successful treatment for spinal injury, the repeated claims about imminent cures have been overplayed, as Geoff Raisman discusses in his Perspective. His article argues for a more careful evaluation of the ability of olfactory ensheathing glia to induce recovery after spinal injury. But in a broader context, Raisman advocates the need to take a more critical look at our current models for the study of spinal cord injury. This point is reiterated by Flint Beal in his review of animal models of Parkinson's disease, and by Ma-Li Wong and Julio Licinio in their article on depression. The three articles converge on the idea that, although animal models are valuable heuristic tools, they have serious limitations that need to be tackled before they can reach their full potential, a view that the author of the Edwin Smith Surgical Papyrus would certainly have endorsed.