The Age-Related Decline in Circadian Output - Literature review Example

?AGE RELATED DECLINE IN CIRCADIAN OUTPUT. College: The experiment investigates the effects of age on the circadian output of rodents as imparted on by changes in the SCN to link with that of human beings. It uses the mice in the test under standard conditions to realize the mechanisms of the circadian clock that involves the Suprachiasmatic Nucleus (SCN). The experiment revolves around the SCN in attempt to realize the process of sleep and attempt to make certain alterations that could be created to be useful in obtaining more stable and healthy sleep for the aging population (p7, methods and protocols) Since the aging process causes changes in the central circadian clock which in turn causes disruption in sleep and wake cycles (Rosato, 2007 P 11) Alterations in key neuropeptides are factors exhibited in the central circadian clock of the aged animals, which lead to a decreased process of glucose utilization (Reet et all 2004 P 40) The decrease in glucose utilization is a result of lack of synchronization from disrupted population of the central circadian clock. It is possible to reverse the reduced rhythmicity caused by age with the use of implanted fetal SCN tissue in the third ventricle. The overall effect is in the behavioral changes as well as the synchrony of such habits. This leads to alterations in the electrophysiology of the aged neurons in the SCN (Watson et al 2012 P 45). The chances portrayed of electrical changes are that the rhythms involving electrical activity useful for circadian output are affected in the early stage of ageing. The process of ageing therefore impacts on the systems as soon as its initial stages (Van, et al 2011 P 4) The studies conducted are aimed at evaluating the rate of circadian rhythms in freely behaving mice of middle age and whether there is reduced spontaneous electrical firing in sub periventricular zone (SPZ). The sleep patterns in human beings however is spread on a larger scale of age that involves teenagers and adults as well as the aged. Both physiological and biological aspects pose as challenges to the method of using rodents to sufficiently fulfil the human sleeping patterns with health (p23 human sleep and cognition basic research.) The animals were put in different housing and put under locomotive activity of a running wheel each one individually. The mice were placed under anesthesia in a second experiment and put on stereotaxic instrument then electrodes were used on the brains to test the SCN and aligned to the skull in a surgical process. The loco motor activity was then recorded along with monitoring the neural activity. After the study was completed the animals’ brains were removed for observation and conformational conclusion, they were anesthized and a positive current passed through the electrodes used for recording previously. The brain that was removed was then placed in phosphate buffer with potassium Ferro cyanide, spots were created to identify deposited iron by staining the serial parts of the brain. The stained cells that represent the immune positive cells were counted by observers who had been blinded to protocol. There was no positive staining in control experiments, where the primary antibody had not been added. The observations made indicated an amplitude reduction in the motor rhythm among the middle aged mice, compared to the other younger mice. Even when they both portrayed the same individual level of functionality in both the LD and darkness DD, the amplitudes were different. The middle aged exhibited both a reduced activity as well as a fragmented one. According to the study more than just the measured parameters decrease with age. This would account for a greater change in human beings since the brain system is yet more complex. The middle age mice among other parameters also portrayed a reduced rhythm in multiunit neural activity. The process of obtaining these results involved implanting a bipolar electrode onto the SPZ (n=10) or the SCN (n=8) to monitor multiunit neural activity MUA in the long run. The young mice, all exhibited a distinctly well laid daily rhythm cycle in MUA in both LD and DD exposures. The MUA however portrayed higher levels and reached peaks during the middle of the day, this observation also reflected that the peak happened in a complete anti phase during locomotive activity. The middle aged SCN on the other hand reflected fluctuating MUA levels that lead to noisy circadian rhythms in the same LD and DD as compared to the younger mice. The multiunit neutral activity correlated with the locomotive activity negatively and the coefficients of the two, SCN and the loco motor activity in the middle aged and in the younger mice differed along negative lines with the coefficient of the younger mice being higher than that of the middle aged animals. Even with the differences, the MUA count daily for the middle aged mice was higher than that of the younger mice and the day to night ratio in the middle aged animals was lower than that of the younger mice. All in all the exhibitions of the younger ice ,in the day to night ratio in SPZ count exceeded that of the count of SCN in the middle aged animals and the SPZ of the younger mice portray a more clear circadian rhythm (Rosato 2007 P 11). Observations created essentially portray the electrical activity amplitudes for rhythm activity from the SCN declining with age as the animals grow older. The observations draw such conclusions as the changes are from primary alterations by the neuronal activity that is linked to rhythmicity created by ageing, since the rhythmicity is an entirely and obvious declining effect. The experiments opt to use in vivo studies as compared to in vitro studies due to the irregularities in the rhythmicity of the middle aged animals SCN. In contrast to the younger animals, the middle aged animals portray variability in their circadian process, between their adjacent intervals of measure (Reeth, et al2001 P 12). During the experiments as well, the activity of rhythmicity may be impacted on by other brain activities in other parts of the brain. In interpretation the lowered rhythmicity reflects as low amplitudes of loco motor activity in electric response on the SPZ Circadian output in humans is useful and developing the overall context of health and its degradation may have consequences upon their physical and mental health in the long run. The general rhythmic development is a way to good health (Goblin,et al 2004 P 32) Breaking of the circadian system or just its weakening can lead to disturbed sleep patterns especially in the aged Studies have shown that in aged people sleep signals are weak during certain periods of the day and increase during early morning thus promoting sleep in the wee and extended morning (Kerkhof,et al 2011 P 90) in the elderly people, treating the circadian system may provide openings for potential ameliorating sleep changes that lead to an increased daytime alertness. Circadian output in the aging persons can be improved without medication by acclimatizing to customed sleep patterns for a long time. It is recommended that depending on age sleep in elderly people be made sufficient in the morning until late morning while teen sleep patterns can be designed by creating dimness at night for healthy development. The findings of this research is useful in determining the overall patterns of sleep in human beings and how those patterns are affected by the factor of age. Bibliography ACKRILL, K. (1995). Circadian clocks and their adjustment. Chichester, Wiley. Burlington, Elsevier Science. http://public.eblib.com/EBLPublic/PublicView.do?ptiID=645037. COSTA, E., & PAUL, S. M. (1991). Neurosteroids and brain function. New York, Thieme Medical Publishers. GOLBIN, A. Z., KRAVITZ, H. M., & KEITH, L. G. (2004). Sleep psychiatry. London, Taylor & Francis. KERKHOF, G. A., & VAN DONGEN, H. (2011). Human Sleep and Cognition Basic Research. VAN REETH, OLIVIER, WEIBEL, LAURENCE, OLIVARES, E, MACCARI, STEFANIA, MOCAER, E., & TUREK, FRED. (2001). Melatonin or a melatonin agonist corrects age-related changes in circadian response to environmental stimulus. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot .ulb.ac.be:2013/55116. ROSATO,E. (2007). Circadian rhythms: methods and protocols. 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