Agingrelated Memory Decline

As most people over the age of 60 will attest, a decline in learning and memory is a part of the "normal" aging process (see reference 1 for a review). Most noticeable in humans is the decline in hippocampus-dependent forms of memory, the learning and remembering of new names, recent events, and even spatial information. For the most part, in normal individuals, these memory deficits are not debilitating, but they are quite noticeable because they are involved so directly in human conscious behavior.

These types of hippocampus-dependent memory dysfunction are recapitulated in aging rodents, as assessed using various learning paradigms that we have discussed throughout this book. Carol Barnes has been a leader in this area and, in fact, developed her maze learning task specifically to probe for memory deficits in aged animals, as was described in Chapter 2. In vivo recordings have also demonstrated deficiencies in hip-pocampal place field stabilization in aged rats (2). Thus, an aging-related decline in behavioral and cellular manifestations of hippocampus-dependent learning is well established in humans and other mammals.

Hippocampal LTP is similarly diminished in aged animals (3). The basis for these declines remains mysterious, although decreased synaptic inputs or diminished NMDA receptor function are possibilities, depending on the hippocampal region under consideration (3, 4). In addition, Marina Lynch's group has executed a nice series of studies implicating excessive production or reactive oxygen species as a contributing factor in aging-related memory and synaptic plasticity dysfunction (5). Given the ambiguous nature of the molecular process we call 'aging," the biochemical mechanisms underlying aging-related memory decline are likely to remain enigmatic for some period of time. This does not diminish the importance of understanding them, but rather highlights their complexity.

Superimposed upon the normal aging process can be much more dramatic insults to the human capacity for hippocampus-dependent learning and memory. These can arise for a number of reasons—stroke, vascular problems, psychiatric disorders, Parkinson's disease, and Alzheimer's disease principally among them. These all can lead to dementia much more pronounced than ever occurs with normal aging. The focus of this chapter will be dementia of the Alzheimer's type.

Please keep in mind that "dementia" does not mean the same thing in the clinical realm that it does in general parlance. "Demented" is generally used by the lay public synonymously with "mad" or "insane." In clinical terms dementia refers to a specific and pronounced decline of cognitive function in humans—a decline in mentation. Among the symptoms of dementia are loss of learning and memory capacity, decline in reasoning ability, attention problems, language difficulties, and problems with perception.

AD is the most common of the tragically debilitating senile (i.e., age-related) dementias, and in the United States alone AD is projected to affect approximately 4 million people total in the next few years. In the United States, about one in ten people over the age of 65 have AD. If you live to age 85 you have about a one in two chance of developing AD. As human longevity increases worldwide, the ironic and at-present unavoidable consequence of that fact is that the prevalence of AD will similarly increase on a global scale. AD is projected to affect nearly 20 million people worldwide by 2025. These are sobering statistics given that at present there is no effective treatment for the disease.

Advanced Memory Techniques

Advanced Memory Techniques

A course in techniques and skills for mentalists, magicians and students. For students, improve your grades with less effort! But this book is also.... The ideal for any stage mentalist or magician by establishing credibility of amazing skills with an easy to follow instructional book on using the amazing power of your memory.

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