Chu C, Murdock MH, Jing D, Won THyung, Chung H, Kressel AM, Tsaava T, Addorisio ME, Putzel GG, Zhou L et al..  2019.  The microbiota regulate neuronal function and fear extinction learning.. Nature. 574(7779):543-548.

Maurer CW, Liu VD, LaFaver K, Ameli R, Wu T, Toledo R, Epstein SA, Hallett M.  2016.  Impaired resting vagal tone in patients with functional movement disorders.. Parkinsonism Relat Disord. 30:18-22.