<Original Article> Age-Related Changes in the Spontaneous Motor Activity during the Dark Phase in the Male Mouse

Spontaneous motor activity was studied in first generation (F1) hybrid C57BL/6 x C3H male mice at the ages of 6, 18 and 36 months. Activity was recorded for 10 consecutive hours during the dark phase, using a capacitance-induction motility monitor. The recordings were taken simultaneously at 2 levels of sensitivity; total activity (T) for the fine and gross movements and large activity (L) for the gross movements. The data were measured in 1 hour intervals and then stored on discs for micro-computer analysis. The T activity decreased with age. Changes in the mean hourly scores of T and L activity with time during the 10 hour dark phase differed among the 3 age groups. The results suggest that spontaneous motor activity during the dark phase is a useful parameter of changes in the motor function in aged mice.journal articl

<Original Article> NMR Spectroscopic Studies on the Urine of Adult Male Mice

To develop a simple and non-invasive method for monitoring the metabolic behavior of experimental animals, NMR spectroscopy was applied to the study of mouse urine constituents. Mice from which urine was obtained were the first male generation hybrid of C57BL/6×C3H at 6 months of age. 1H-NMR spectra at 270 MHz or 400 MHz and 13C-NMR spectra at 100 MHz of the urine (0.3-0.5 ml) were measured by JEOL spectrometers. From the spectra obtained, we have identified citrate and 10 nitrogenous excretion products as urine constituents, in which trimethylammonium and dimethylammonium ions and trimethylamine oxide were confirmed by NMR and mass spectroscopies. The concentrations and the relative ratios of the urine constituents were determined and may serve a criterion for evaluating the metabolic behavior and physiological condition of mice.journal articl