[1] Univ Calif Los Angeles, David Geffen Sch Med, GLA VA MC,Ctr Neurovisceral Sci & Womens Hlth, Dept Med,Div Digest Dis, Los Angeles, CA 90073 USA
[2] Univ Calif Los Angeles, David Geffen Sch Med, Ctr Neurovisceral Sci & Womens Hlth, Dept Physiol, Los Angeles, CA 90073 USA
[3] Univ Calif Los Angeles, David Geffen Sch Med, Ctr Neurovisceral Sci & Womens Hlth, Dept Psychiat & Biobehav Sci, Los Angeles, CA 90073 USA