1. Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA.
2. Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
3. Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA.
4. Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.