According to the August issue of ScienceDaily, researchers from the Harvard University have unveiled a mechanism through which caloric restriction and exercise postpone a number of the weakening effects of aging through the rejuvenation of the connections between the nerves and the muscles that are under their control.
The research was carried out in the laboratories of Joshua Sanes and Jeff Lichtman. It had been published in the journal Proceedings of the National Academy of Sciences. Initially the research gives an explanation of the findings regarding the exercise and restricted-calorie diets that assist in staving off the physical and mental degeneration that is caused by the process of aging.
Sanes who is the director of the Center for Brain Science at the Harvard University as well as a professor of molecular and cellular biology states that exercise and caloric restriction have a number of dramatic effects motor ability and mental acuity. The research that has been conducted provides one to have a hint regarding the way these exceptionally powerful lifestyle factors operate is through the attenuation or reversion in our synapses.
Sanes declares that their research has been carried out with mice which have been genetically engineered so that their nerve cells are able to glow in fluorescent colours. It shows that a number of the debilitation of aging is triggered by the deterioration of connections that nerve make with the muscles that they control. These structures are known as neuromuscular junctions. These connections are microscopic in nature. They are surprisingly alike to synapses that link neurons to shape information-processing circuit in the brain.
In a situation where the neuromuscular synapse is healthy, the nerve endings and their receptors found on the muscle fibres are nearly a perfect match, similar to two hands that are placed together, finger to finger and palm to palm. This line up makes sure that there is maximum efficiency in the transmission of the nerve’s signal from the brain to the brain as this is what makes it contract during a movement.
Nonetheless, as a person ages, his neuromuscular synapses can get worsen in various ways. His nerves can shrink and as a result fail to completely cover the muscle’s receptors. The ensuing interference with the transmission of nerve impulses to the muscles can bring about wastage and eventually even the death of the muscle fibres. This wastage of the muscle is known as sarcopenia. The later is a known and critical clinical problem that is found among the elderly people.
The new piece of work that has been done demonstrated that mice, which were put on a restricted-calorie diet, were able to avoid deterioration of their neuromuscular junctions caused by aging, to a large extent. On the other hand, the mice that were on a one-month exercise regimen when they had already aged reverse the damage to a certain degree.
In accordance to Sanes they were able to see reversal of all facets of the synapse disassembly by implementing calorie restriction. However, with exercise they did witness a reversal of the majority, but not all.
Due to the structure of the study, that is, the mice were kept on calorie-restricted diets during their entire lifetime whilst those that perform exercise did so for only a month late in life, Sanes warns against drawing conclusions in regards to the effectiveness of exercise compared to calorie restriction. Furthermore he notes that extended periods of exercise have more intense impacts. Sanes and Lichtman are currently testing this possibility.
Even though the majority of Sanes and Lichtman’s work concentrates on brain synapse, both of them have examined neuromuscular synapses for several years. Neuromuscular junctions are sufficiently large to be viewed through light microscopy. As such, it can be a jumping-off point for brain study, by stressing on the areas of inquiry and probable methods. Sanes is of view that these findings in neuromuscular synapses sharpen their curiosity to find whether similar impacts might take place in brain synapses.
Even while the alterations to the synapses by the means of caloric restriction and exercise were lucid in the images that the researchers obtained, Sanes warned that their work structural instead of functional. Moreover they have not yet examined the extent to which the synapses worked well.
Source: Science Daily and E-science News
Sun, Aug 8, 2010
Anti Aging, Bioscience, Health And Aging