What does a dolphin's brain look like? And an elephant's? Let's face it, with the exception of a cursory look at a human brain during graduate school, rat and mouse brains are as good as it gets for most neuroscientists. But if you want to expand your repertoire, you should definitely pay a visit to the Comparative Mammalian Brain Collections (CMBC) web site, which features an extraordinary collection of brains from a broad spectrum of mammalian orders. There you will find neuroanatomical information on species as exotic as the manatee or as ordinary as the cow and the pig.

The CMBC site contains complete brain atlases of at least 15 species, which can be displayed as photographs or as movies that allow you to take a quick look through sections of the whole brain. There are also whole-brain photographs from nearly 200 different mammals, most of which are accompanied by at least one coronal section to get a glimpse of the inner structure of these nervous systems. In addition, there is a page devoted to 'paleoneurology' — the analysis of brain endocasts from extinct vertebrates — which provides a useful introduction to the study of brain evolution.

It is clear that the CMBC site is work in progress and that much needs to be done to exploit the full potential of the available material. For example, the brain sections would benefit from some labelling and tools could be made available to allow for direct anatomical comparisons between species. As the collections will soon be moved to the National Museum of Health and Medicine (which itself contains a remarkable collection of human brain sections), their relocation will be a good opportunity to further improve what is already a valuable resource.