1. Laboratory of Central Nervous System Injury and Regeneration; Department of Veterans Affairs Medical Center; Washington DC 20422 U.S.A.
2. Stroke and Trauma Laboratory; Department of Veterans Affairs Medical Center; Washington DC 20422 U.S.A.
3. Department of Physiology; The George Washington University School of Medicine; Washington DC 20037 U.S.A.
4. Will Rogers Institute and Altschul Laboratory for Dementia Research; Burke Medical Research Institute; Cornell University Medical College; 785 Mamaroneck Avenue White Plains NY 10605 U.S.A.