Mouse Measuring the Seasonal Time. (Mice on the Ancient Japanese Clock 'wadokei') (image) Institute of Transformative Bio-Molecules (ITbM), Nagoya University Share Print E-Mail Caption In the ancient Japanese timekeeping system, the length of one hour varied with the seasons (i.e. 24 hours was divided into 6 hours of daylight and 6 hours of night-time. Daylight hours were longer in the summertime and shorter in the winter). Laboratory mice were believed to be non-seasonal animals for a long time. Ono et al. reported that mice transmit seasonal information from the pituitary gland to the hypothalamus by using thyrotropin. Credit Takashi Yoshimura, ITbM, Nagoya University Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.