Animals
We purchased five-week-old male ddY mice (Japan SLC, Shizuoka, Japan), used them during the age of six weeks, and attempted to minimize the number of animals used and their suffering. All animals were kept in a controlled environment with a 12:12-h light schedule, temperature (23 °C), and relative humidity (55 ± 5%), and were provided ad libitum access to food and water. All experiments were performed according to internationally followed ethical standards and approved by the research ethics committee of Tokyo University of Science, which was conducted according to the guidelines of the National Institute of Health and Japan Neuroscience Society.
Drugs and chemicals
All drug solutions were freshly prepared before use. STZ and 5, 5′-dithiobis (2-nitrobenzoic acid) (DNTB) were from Sigma-Aldrich (St. Louis, MO, USA). GLP-2 was from Peptide Inc. (Osaka, Japan). All other…
