The choice of the intervention we are going to apply is based on two `` proof of concept '' studies in humans ( Proc Natl Acad Sci USA 107:1207 -1210 , 2010 ; Ann N Y Acad Sci 1252:253 -258 , 2012 ; Frontiers Syst Neurosci 6:50 , 2012 ; PloS One 6 ( 9 ) : e24685 , 2011 ) and on a recent animal study ( Front Syst Neurosci 7:21 , 2013 ) .