CONCLUSION

When confronted with a neurological or psychiatric disorder in an elderly individual, a clinician is likely to ask how the processes of ageing have influenced the aetiology and presentation of the disorder, and will impact on its efficient management. The clinician then seeks information about the ageing of the brain to make informed judgements and choices. There are many urban myths about ageing, and some of these apply to the brain. The reviews included in this book are an attempt to flush out these myths, and arm the clinician and general researcher with the empirical facts that can be mustered to substantiate claims about ageing. There are many salient questions: Is cognitive change to be expected in an elderly individual? Is this change progressive, relentless and unselective, or is it focal and constrained? Would every person who lived long enough develop Alzheimer’s disease (AD)? Do our neurones die as we grow old? What happens to the size of the brain and its metabolic activity? How do our hormones change with age? Can anti-oxidants slow or even stop the process of ageing? Are genes important for the ageing brain, or is it all in the environment? How much of what we are is due to what we eat? This book has addressed some of these questions in a language simple enough for a general reader to understand. Does this book also lay out a guide map for the future researcher of brain ageing? The field is too diverse to recommend any one road to the traveller. A cognitive neuroscientist, for example, has a very different perspective from that of an endocrinologist when dealing with age-related processes. Genuine

breakthroughs will depend, however, on the successful marriage of such diverse outlooks. The emerging role of glucocorticoids in stress, depression, memory dysfunction, brain atrophy and ageing is one example of the power of cross-fertilization. The research on oxidative stress in ageing has led to the growth of a large industry extolling the virtues of antioxidants. The observations on older women have led to the examination of the role of oestrogen in the regulation of neural plasticity. Cross-disciplinary research is more than a mere fad in relation to the future development of this field. Much of the progress in the future is likely to come from predictable quarters. The hunt is on for the genes that regulate the development and senescence of the brain. It is inevitable that this will one-day lead to their manipulation to modify these processes, fraught though this will be with ethical dilemmas. New technology will continue to challenge and astound us. In the last two decades, the introduction of neuroimaging techniques has changed the way we look at the brain. These technologies continue to evolve, and are being complemented by developments in histopathology, such as confocal laser microscopy, which enable us to examine single cells in great detail. Advances in mass spectrometry have opened up the study of proteins and led to the development of proteomics to complement the revolution in genomics. In medical science, many advances have come from the study of disease processes, which may be considered nature’s joints that a researcher can hope to carve. The quintessential disorder of ageing is AD, and its study holds the promise of many insights about nature’s ways. Solving the riddle of plaques and tangles may not solve the problem of ageing, but has the potential of altering the landscape considerably. No other disorder has given more impetus to the study of degeneration of the brain, but it may be only the beginning. There is a limited number of ways in which brain cells lose their vitality or viability in the aged, and some of these leave footprints such as neuronal inclusions or inter-cellular deposits. We do not know why Lewy bodies develop in the cortices of some individuals. We have little understanding of tauopathies, and why some degeneration begins in the temporal lobes, while others may start in the frontal, parietal or even the occipital lobes. More than a decade after the discovery of the Huntington’s gene, we do not fully understand the process of neuronal loss in this disease, and have no method of stopping or modifying it. The researcher of the future will be well served by following the footprints of nature in discovering some insights. This book can be criticized for under-emphasizing the sociological aspects of brain ageing. The aged brain possesses a wealth of knowledge and experience, which it holds on to even in the presence of other devastation, and passes onto future generations. The brain also has an elegant ability to adapt to changing circumstances. It has a built-in reserve that protects it in adversity, and education, mental activity and healthy lifestyle can increase the reserve. Nutritional and lifestyle factors may also retard the disease processes of old age. These factors hold the potential for living well in old age, and to

stay engaged in family and society. As the demographic shift to old age occurs in our society, there are increasing opportunities for the elderly individual and his or her brain. While we cannot protect the brain forever, we can strive to maximize its quality well into old age if we are to build a happy and productive future. While tabloid science abounds on this issue, it is hoped that this book will bring empirical science to bear on any such quest.