I've just found this Encyclopaedia of Computational Neuroscience on Scholarpedia. Each entry is written by an expert in the field, and is very comprehensive.
The project seems to have been started only recently, as many of the entries I've looked at are still empty. Although still incomplete, this is already a fantastic resource that's well worth looking at.
Here are just a few of the finished entries: grid cells by Edvard Moser, mirror neurons by Giacomo Rizzolatti, synaesthesia by V.S. Ramachandran, and the neural correlates of consciousness by Cristof Koch.
Others who have accepted the invitation to author articles for the encyclopeadia include Tim Bliss (on LTP), Brenda Milner (on the famous amnesic patient H.M.), Gordon Shepherd (on dendro-dendritic synapses) and Marvin Minsky (the perceptron).