[1] Vet Affairs Med Ctr, Med Serv, Minneapolis, MN 55417 USA
[2] Vet Affairs Med Ctr, Ctr Geriatr Res Educ & Clin, Minneapolis, MN 55417 USA
[3] Univ Minnesota, Dept Med, Minneapolis, MN 55455 USA
[4] Univ Minnesota, Dept Psychiat, Minneapolis, MN 55455 USA
[5] INRA, UMR 1225, F-31076 Toulouse, France
[6] Univ Toulouse, ENVT, UMR 1225, F-31076 Toulouse, France