National Defense Medical College 1 article published in JoVE Medicine Microscopic Observation of Lymphocyte Dynamics in Rat Peyer's Patches Kazuhiko Shirakabe1,2, Masaaki Higashiyama1, Naoki Shibuya2, Kazuki Horiuchi1, Masayuki Saruta2, Ryota Hokari1 1Department of internal medicine, National Defense Medical College, 2Division of Gastroenterology and Hepatology, Department of Internal Medicine, Jikei University School of Medicine Here, we describe a precise method for collecting thoracic duct lymphocytes and observing the migration of gut-tropic lymphocytes in rat Peyer’s patches for 3 hours using time-lapse photography. This technique can clarify how the dynamics of lymphocytes are affected under inflammatory conditions.