Diurnal variations in 23 blood chemical items were investigated in Sprague-Dawley rats of both sexes at 6 weeks of age. Blood samples were obtained every two hours. One to three periodic components detected by the maximum entropy method from the observed time-series and the optimum fitting parameters were calculated by the least squares method. The fitting curves were compared with the observed data for the evaluation of systematic and fluctuating parts of the time domain as circadian variations. The periodic components were detected from all the blood chemical items examined. This suggests that all items have systematic parts as basic rhythmic changes. The optimum fitting curves corresponded to the observed time-series in the following items: glucose, total protein, A/G ratio, alkaline phosphatase, Na, K, Cl and BUN of both sexes and total cholesterol, triglyceride, cholinesterase, CPK, inorganic phosphorus, direct and total bilirubin, creatinine and uric acid in males. Others showed insufficient correspondence to many fluctuating parts. This randomness was more frequently seen in females than in males.
The simultaneous recording system for body weight, food and water consumption and behavior (spontaneous motor activity and drinking and feeding behavior) of a mouse was developed. The body weight and food consumption were measured by force transducers. Food and water consumption and drinking and feeding behavior were measured by an infrared luminous diode and a phototransistor. Spontaneous motor activity was measured by photosensors. The system control and data acquisition were performed by using a personal computer. Every parameter could be monitored with a desired time interval. All the data collected by this system revealed apparent circadian rhythm. In conclusion, this system would be a powerful tool for pharmacological and/or toxicological research.
Analysis of circadian locomotor activity, Golgi-Cox impregnation, and immunohistochemistry were studied on the hereditary microphthalmic rat which congenitally lacked the optic nerve. These blind rats showed free-running circadian rhythms in their locomotor activities. Both the normal and microphthalmic rats had similar ultradian rhythms in addition to circadian rhythms. The neuronal cell population and volume of the hypothalamic suprachiasmatic nucleus (SCN) of the microphthalmic rats were 66% and 71% of those in normal rats, respectively. The number of SCN neurons containing vasoactive intestinal peptide-like immunoreactive substance was dramatically decreased to 35% of that in normal rats. Golgi-Cox impregnation revealed that three types of neurons in the SCN of the microphthalmic rats were consistently distinguished as observed in normal rats. Although there were no changes in the numbers of primary dendrites of the SCN neurons in the microphthalmic and normal rats, the number of secondary and tertiary dendrites in the SCN of the microphthalmic rats was smaller than that of normal rats. These observations suggest that the retinal input may be important for normal morphological formation of the SCN during development, but not for the generation of circadian rhythms and ultradian rhythms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.