Correction

MEDICAL SCIENCES. For the article “Anandamide and diet: Inclusion of dietary arachidonate and docosahexaenoate leads to increased brain levels of the corresponding N-acylethanolamines in piglets” by Alvin Berger, Gayle Crozier, Tiziana Bisogno, Paolo Cavaliere, Sheila Innis, and Vincenzo Di Marzo, which appeared in number 11, May 22, 2001, of Proc. Natl. Acad. Sci. USA (98, 6402–6406; First Published May 15, 2001; 10.1073/pnas.101119098), the authors note the following. On page 6404, right column, 4 lines from bottom, “pmol/mg brain lipid extract” should read “pmol/g wet weight of brain tissue.”