The Whole Brain Atlas, sponsored by Brigham and Women's Hospital, Harvard Medical School, Countway Library of Medicine, and the American Academy of Neurology, includes MRI and PET images of the normal brain as well as those with different forms of degenerative disease.

The Allen Institute provides open access to their brain atlases and data sets for the use of the general scientific community.

This site from Michigan State University includes atlases for human, sheep, dolphin, and axolotl brains.

Brain Maps includes interactive atlases of both primate and non-primate brains.

SynapseWeb offers a 3D atlas of neurocytology, as well as anatomy tutorials.

The Allen Institute provides open access to their brain atlases and data sets for the use of the general scientific community.

The ADNI provides multiple types of datasets, including MRI and PET images, genetics, cognitive tests and blood biomarkers, related to Alzheimer's disease.

CRCNS provides a platform for sharing tools and data, including physiological recordings and eye movement data.

OpenNeuro, associated with Stanford University, is a "free and open platform for sharing MRI, MEG, EEG, iEEG, and ECoG data". Share your data or find other datasets to use in your analysis.

The NIF provides access to a number of resources, including data, software and tools.

The NIH maintains a number of repositories for sharing your data and making it openly accessible.

SciCrunch, hosted at UC San Diego, is more than a data sharing space. It also offers users a way to create a search portal that accesses resources relevant to their research.