[1] Pontificia Univ Catolica Chile, Escuela Med, Dept Gastroenterol, Santiago, Chile
[2] Pontificia Univ Catolica Chile, Fac Ciencias Biol, Dept Biol Celular & Mol, Ctr Envejecimiento & Regenerac CARE, Santiago, Chile
[3] Vanderbilt Univ, Med Ctr, Div Gastroenterol Hepatol & Nutr, Nashville, TN 37212 USA
[4] NIDA, Clin Psychoneuroendocrinol & Neuropsychopharmacol, Intramural Res Program, NIH, Baltimore, MD USA
[5] NIAAA, Div Intramural Clin & Biol Res, NIH, Bethesda, MD USA
[6] NIDA, Medicat Dev Program, Intramural Res Program, NIH, Baltimore, MD USA
[7] Brown Univ, Sch Publ Hlth, Dept Behav & Social Sci, Ctr Alcohol & Addict Studies, Providence, RI 02912 USA
[8] Johns Hopkins Univ, Sch Med, Dept Med, Div Addict Med, Baltimore, MD 21205 USA
[9] Georgetown Univ, Med Ctr, Dept Neurosci, Washington, DC 20007 USA
[10] Univ Pittsburgh, Med Ctr, Div Gastroenterol Hepatol & Nutr, Pittsburgh, PA USA
[11] Mayo Clin, Div Gastroenterol & Hepatol, Rochester, MN USA