Topics for Essays:
Neural Plasticity and the effect of environmental enrichment on adult development
Neural Plasticity
The brain compensates for age-related changes. These changes in the structure and functioning of the brain is
known as neural plasticity. Neural plasticity occurs as a result of the interaction between the brain and the
environment, as well as learning from experiences over the life-span. Neural plasticity provides a way to
understand how the brain changes in order to compensate for age-related changes through the reorganisation
of neural circuitry in the brain.
Neural stem cell research
The brain is capable of generating new neurons, even into late life, and under the right circumstances (when
compensating for age-related declines through plasticity). Neural stem cells are the cells in the Central
Nervous System. Neural stem cells have shown that neurogenesis does not stop at the end of embryonic
development, but rather continues throughout the life-span. As people age, the number of new neurons
decreases, however, this is dependant on the different brain regions. The brain is capable of generating new
neurons even in late life.
The effect of environmental enrichment on neural pasticity
Some research has focused on whether training, which results in plasticity, can improve cognitive functioning.
Researched has found that speciality strategy training can improve cognitive functioning in older adults
through memory tasks. However, this improvement is very task specific. Other research has shown that
training that improves cognitive functioning can improve other types of functioning, as long as the tasks share
the same basic underlying functions. This improvement in cognitive functioning occurs because the training
increases the level of activity in the prefrontal cortex. Therefore, it appears that an environment that has tasks
that are designed to improve neural plasticity can help improve the cognitive functioning of older adults.
, Exercise and Brain Aging
Research has shown that aerobic exercise can enhance brain plasticity. In fact, it can counter declines in the
hippocampus that is associated with Alzheimer’s disease. Some research has found that aerobic fitness
increased the volume of the hippocampus, which in turn improved performance in spatial memory tasks.
Nutrition and Brain Aging
Certain foods result in benefits for the brain. Vitamins B, C, D, and E, and omega-3 fatty acids are associated
with better cognitive functioning and greater brain volume. There are two types of omega-3 fatty acids EPA
and DHA. EPA helps prevent atrophy in the amygdala which is associated with memory declines and symptoms
of depression. Transfat has been found to effect cognitive functioning negatively.
Implications for health care policies
It is generaly assumed that as people age cognitive performance declines because the brain gradually loses
tissue. However, research is starting to discover ways in which this decline can be reduced. Furthermore,
certain areas of the brain are relatively preserved and some areas may even show growth. In this regard,
research on neural plasticity can help in developing better health care policies that can improve cognitive
performance in older adults. Research has shown that aerobic exercise and a healthy and nutrient rich diet can
help to improve cognitive functioning. By designing health care policies that incorporate interventions that
improve diets and promote exercise for the aging, it can help older adults to live a healthier life.
1. Interaction between psychological, sociocultural, life-cycle and biological forces – use an example
Biological theories of aging and how these explain biological and physiological aging
There has been much research conducted in an attempt ot explain why we age. However, even though many
hypothesis have been put forward about the biological reasons for aging, none of these existing theories
,provides a complete explanation. Aging should be seen as an interaction between psychological, sociocultural,
life-cycle and biological forces.
Metabolic Theories
This theory states that all organisms have only so much energy to expend in a lifetime. It further states that
the rate of a creature's metabolism is related to how long it lives. While this theory is one of the more popular
ones, it does not provie a full explanation of why we age. Some research has shown that significantly reducing
the amount of calories consumed can increase longevity. However, research on primates has shown that
restricting calorie intake only does not always result in longer life span. It has also been suggested that these
types of diets would result in a poor quality of life, because, the calorie restriction would be extreme. Because
these diets are so extreme, it is assumed that the restrictions in calorie intake would result in people not being
able to engage in many activities that are necessary for a good quality life. Therefore, restricting calorie intake
alone does not result in longevity, meaning that metabolic theories do not fully explain aging, and in fact may
be detrimental to quality of life. therefore, other psychological, sociocultural, life-cycle and biological forces
must be taken into consideration.
Cellular Theories
There are two different cellular theories that have been proposed. The first cellular theory focuses on the
number of times cells can divide, which limits the life span of an organism. A phenomenon that occurs is
called the Hayflick limit. Cells seem to divide a certain (fixed) amount of times before dying. The number of
possible divisions decreases the older the donor organism is. For example, cells from human fetal tissue divide
40 to 60 times while cells from a human adult are divide about 20. This means that there is a limit on the
number of times that a cell can divide, even when there are no other influencing factors. Research has
suggested that the reason a cell limits the amount of divisions is due to telomeres. Healthy, normal telomeres
help regulate the cell division and reproduction process. An enzyme called telomerase is required in DNA
replication to fully reproduce the telomeres when cells divide. With each replication the telomeres become
shorter. When the telomeres become too short, the chromosomes become unstable and cannot replicate.
There is research available that exercise may help to maintain telomere length which may help to slow the
aging process. Other research indicates that chronic stress may speed up the shortening of telomeres, which in
turn may shorten the life span. This research indicates that life-cycle forces may influence the rate of how fast
telomeres shorten and therefore, how fast aging occurs.
, A second cellular theory is based on cross-linking, in which collagen interacts randomly and produces
molecules that make the body stiffer. The more cross-links there are, the stiffer the tissue. As we age, the
number of cross-links increases which may explain why the heart and arteries become stiffer with age.
However, cross linking is not an adequate explanation for aging as few studies have shown that cross-linking
impedes metabolic processes or causes the formation of faulty molecules that would explain a cause of aging.
A third cellular theory proposes that aging is caused by unstable molecules called free radicals. Free radicals
are highly reactive chemicals produced randomly in normal metabolism. When these free radicals interact
with nearby molecules,they may cause damage to other cells. Research involving substances, called
antioxidants, prevent the formation of free radicals by preventing oxygen from combining with molecules that
are susceptible to forming free radicals. Research has shown that antioxidants may help postpone the
development of certain age-related diseases such as cancer, cardiovascular disease, and immune system
dysfunction. However, there is no evidence that eating a diet high in antioxidants actually increases the life
span.
Genetic Programming Theories
This theory postulates that aging may be a part of our genetic code. Researchers believe that even when cell
death appears random, this is actually part of our genetic programming. It is theorised that this programmed
cell death is a function of physiological process, the inborn ability of cells to self-destruct, and the ablity of
dying cells to triggerimportant processes in other cells. All these aspects are influenced by external
environmental factors. It is still not known how this self-destruct process is triggered or how it works.
Evidence suggests that many diseases associated with aging have a genetic basis, for example Alzheimer’s
disease.
Interactions between the developmental forces
While there is much evidence that aging is influenced by biological forces, none of these theories provides
enough evidence to suggest that aging can be attributed to biological forces only. Rather, aging should be
viewed through an integrative approach that incorporates psychological, sociocultural, life-cycle and biological
forces. In fact changes in body systems and diseases are influenced by these other factors.
This concept can be best illustrated through the use of an example. Research has shown that certain biological
forces can increase or shorten the life-span, telomeres can be lengthened through exercise, but chronic stress
Neural Plasticity and the effect of environmental enrichment on adult development
Neural Plasticity
The brain compensates for age-related changes. These changes in the structure and functioning of the brain is
known as neural plasticity. Neural plasticity occurs as a result of the interaction between the brain and the
environment, as well as learning from experiences over the life-span. Neural plasticity provides a way to
understand how the brain changes in order to compensate for age-related changes through the reorganisation
of neural circuitry in the brain.
Neural stem cell research
The brain is capable of generating new neurons, even into late life, and under the right circumstances (when
compensating for age-related declines through plasticity). Neural stem cells are the cells in the Central
Nervous System. Neural stem cells have shown that neurogenesis does not stop at the end of embryonic
development, but rather continues throughout the life-span. As people age, the number of new neurons
decreases, however, this is dependant on the different brain regions. The brain is capable of generating new
neurons even in late life.
The effect of environmental enrichment on neural pasticity
Some research has focused on whether training, which results in plasticity, can improve cognitive functioning.
Researched has found that speciality strategy training can improve cognitive functioning in older adults
through memory tasks. However, this improvement is very task specific. Other research has shown that
training that improves cognitive functioning can improve other types of functioning, as long as the tasks share
the same basic underlying functions. This improvement in cognitive functioning occurs because the training
increases the level of activity in the prefrontal cortex. Therefore, it appears that an environment that has tasks
that are designed to improve neural plasticity can help improve the cognitive functioning of older adults.
, Exercise and Brain Aging
Research has shown that aerobic exercise can enhance brain plasticity. In fact, it can counter declines in the
hippocampus that is associated with Alzheimer’s disease. Some research has found that aerobic fitness
increased the volume of the hippocampus, which in turn improved performance in spatial memory tasks.
Nutrition and Brain Aging
Certain foods result in benefits for the brain. Vitamins B, C, D, and E, and omega-3 fatty acids are associated
with better cognitive functioning and greater brain volume. There are two types of omega-3 fatty acids EPA
and DHA. EPA helps prevent atrophy in the amygdala which is associated with memory declines and symptoms
of depression. Transfat has been found to effect cognitive functioning negatively.
Implications for health care policies
It is generaly assumed that as people age cognitive performance declines because the brain gradually loses
tissue. However, research is starting to discover ways in which this decline can be reduced. Furthermore,
certain areas of the brain are relatively preserved and some areas may even show growth. In this regard,
research on neural plasticity can help in developing better health care policies that can improve cognitive
performance in older adults. Research has shown that aerobic exercise and a healthy and nutrient rich diet can
help to improve cognitive functioning. By designing health care policies that incorporate interventions that
improve diets and promote exercise for the aging, it can help older adults to live a healthier life.
1. Interaction between psychological, sociocultural, life-cycle and biological forces – use an example
Biological theories of aging and how these explain biological and physiological aging
There has been much research conducted in an attempt ot explain why we age. However, even though many
hypothesis have been put forward about the biological reasons for aging, none of these existing theories
,provides a complete explanation. Aging should be seen as an interaction between psychological, sociocultural,
life-cycle and biological forces.
Metabolic Theories
This theory states that all organisms have only so much energy to expend in a lifetime. It further states that
the rate of a creature's metabolism is related to how long it lives. While this theory is one of the more popular
ones, it does not provie a full explanation of why we age. Some research has shown that significantly reducing
the amount of calories consumed can increase longevity. However, research on primates has shown that
restricting calorie intake only does not always result in longer life span. It has also been suggested that these
types of diets would result in a poor quality of life, because, the calorie restriction would be extreme. Because
these diets are so extreme, it is assumed that the restrictions in calorie intake would result in people not being
able to engage in many activities that are necessary for a good quality life. Therefore, restricting calorie intake
alone does not result in longevity, meaning that metabolic theories do not fully explain aging, and in fact may
be detrimental to quality of life. therefore, other psychological, sociocultural, life-cycle and biological forces
must be taken into consideration.
Cellular Theories
There are two different cellular theories that have been proposed. The first cellular theory focuses on the
number of times cells can divide, which limits the life span of an organism. A phenomenon that occurs is
called the Hayflick limit. Cells seem to divide a certain (fixed) amount of times before dying. The number of
possible divisions decreases the older the donor organism is. For example, cells from human fetal tissue divide
40 to 60 times while cells from a human adult are divide about 20. This means that there is a limit on the
number of times that a cell can divide, even when there are no other influencing factors. Research has
suggested that the reason a cell limits the amount of divisions is due to telomeres. Healthy, normal telomeres
help regulate the cell division and reproduction process. An enzyme called telomerase is required in DNA
replication to fully reproduce the telomeres when cells divide. With each replication the telomeres become
shorter. When the telomeres become too short, the chromosomes become unstable and cannot replicate.
There is research available that exercise may help to maintain telomere length which may help to slow the
aging process. Other research indicates that chronic stress may speed up the shortening of telomeres, which in
turn may shorten the life span. This research indicates that life-cycle forces may influence the rate of how fast
telomeres shorten and therefore, how fast aging occurs.
, A second cellular theory is based on cross-linking, in which collagen interacts randomly and produces
molecules that make the body stiffer. The more cross-links there are, the stiffer the tissue. As we age, the
number of cross-links increases which may explain why the heart and arteries become stiffer with age.
However, cross linking is not an adequate explanation for aging as few studies have shown that cross-linking
impedes metabolic processes or causes the formation of faulty molecules that would explain a cause of aging.
A third cellular theory proposes that aging is caused by unstable molecules called free radicals. Free radicals
are highly reactive chemicals produced randomly in normal metabolism. When these free radicals interact
with nearby molecules,they may cause damage to other cells. Research involving substances, called
antioxidants, prevent the formation of free radicals by preventing oxygen from combining with molecules that
are susceptible to forming free radicals. Research has shown that antioxidants may help postpone the
development of certain age-related diseases such as cancer, cardiovascular disease, and immune system
dysfunction. However, there is no evidence that eating a diet high in antioxidants actually increases the life
span.
Genetic Programming Theories
This theory postulates that aging may be a part of our genetic code. Researchers believe that even when cell
death appears random, this is actually part of our genetic programming. It is theorised that this programmed
cell death is a function of physiological process, the inborn ability of cells to self-destruct, and the ablity of
dying cells to triggerimportant processes in other cells. All these aspects are influenced by external
environmental factors. It is still not known how this self-destruct process is triggered or how it works.
Evidence suggests that many diseases associated with aging have a genetic basis, for example Alzheimer’s
disease.
Interactions between the developmental forces
While there is much evidence that aging is influenced by biological forces, none of these theories provides
enough evidence to suggest that aging can be attributed to biological forces only. Rather, aging should be
viewed through an integrative approach that incorporates psychological, sociocultural, life-cycle and biological
forces. In fact changes in body systems and diseases are influenced by these other factors.
This concept can be best illustrated through the use of an example. Research has shown that certain biological
forces can increase or shorten the life-span, telomeres can be lengthened through exercise, but chronic stress
