. 2018 Jul 31;12:47. doi: 10.3389/fninf.2018.00047
At least a portion of this work is authored by David M. Lovinger on behalf of the U.S. Government and, as regards Dr. Lovinger and the US government, is not subject to copyright protection in the United States. Foreign and other copyrights may apply.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.