One can lose up to 10,000 nerve cells per day as one gets older. Although there is an inevitable loss of all cells in the body due to aging, nerve cells don’t reproduce and are not replaced. The loss of nerve cells causes a decrease in function in the nervous system. The individual and the number of cells that have been lost will determine the function that has been lost.
It is unlikely that nerve cells will be lost routinely until the elderly, as more nerve cells are necessary to maintain the nervous system’s proper functioning.
Along with the endocrine and nervous systems, the nervous system controls and integrates all of the body’s tissues and organs. It processes sensory input from organs like the eyes, ears, skin, and brain and then responds via various organs.
“Ageing leads to a progressive loss of neurons and depletion of neurotransmitters” (Mather, 2016), “these changes are usually associated with a gradual decline in cognitive function and influenced by environmental, genetic and lifestyle factors” (Nyberg et al., 2012).
In this article, resTORbio will talk about How Does Aging Affect The Nervous System? Reading to learn more about the change of our brain and have a better life.
As people age, brain function changes. As a child grows up, their ability to reason and think steadily increases. This allows them to develop more complex skills.
Brain function is stable for most of adulthood.
Brain function decreases after a certain age which varies from one person to another. While some brain areas may shrink by as much as 1% each year, others experience no loss in function. Age-related changes to the brain structure don’t always lead to loss of brain function.
However, a decrease in brain function with aging may result from numerous factors that include changes in brain chemicals (neurotransmitters), changes in nerve cells themselves, toxic substances that accumulate in the brain over time, and inherited changes. At different times, brain function can be affected in different ways:
The ability to retain short-term memories and learn new material is often affected very early.
Later, verbal abilities (including vocabulary and word usage) may start to decline.
If there are no neurologic or other vascular conditions, academic performance (the ability to process information at a reasonable speed) is usually maintained.
Because the brain processes nerve impulses slower, reaction time and task performance may be affected.
The effects of aging on brain function can be hard to distinguish from other disorders common in older people. These disorders include stroke, depression, hypothyroidism, and other degenerative brain diseases such as Alzheimer’s.
The number of nerve cells in the brain can decrease with age. However, it can vary greatly depending on how well a person is doing.
Some types of memory, like those that hold information temporarily, are more susceptible to being lost. Certain brain characteristics can compensate for these losses.
Redundancy: The brain is unable to function properly if it has too many cells. Redundancy can help to compensate for nerve cell loss that is caused by aging or disease.
Formation of new connections: This is how the brain compensates for the decline in nerve cells with age by creating new connections among the remaining nerve cells.
New nerve cells may be produced: Some brain areas can produce new nerve cells after brain injury or stroke. The hippocampus is responsible for the retrieval and formation of memories. The basal ganglia coordinates and smoothes out movements.
People who have suffered a stroke or brain injury can learn new skills through occupational therapy.
Brain function can be affected by people. Exercise, for example, seems to slow down the loss of nerve cells in the areas of the brain that are involved in memory. This exercise helps to keep nerve cells functional. However, drinking more alcohol per day can lead to brain dysfunction.
The average 20% decrease in blood flow to the brain with age may be due to a decline in blood flow. People with cerebrovascular disease (atherosclerosis) experience a greater decrease in blood flow.
People who smoke for a prolonged period or have high blood cholesterol, high blood pressure, or diabetes mellitus (high blood sugar) that are not controlled with lifestyle changes or drugs are more susceptible to this disease.
These individuals may experience a rapid decline in brain cell count, leading to impairments in mental function. The risk of developing vascular Dementia is higher in these individuals, especially if the blood vessels are damaged at an early age.
Age-Related Dysfunctions to the Nervous System
Reduced reflex responses
As we age, our reflex responses begin to decrease around 60. This includes the loss of reflexes at the ankle, knee, and tricep muscles.
Declining autonomic responses
The autonomic nervous systems control the body’s temperature and pulse rate. As we age, our bodies become less able to maintain a constant temperature, even during extreme heat or cold.
We also have to return to normal heart rate after exercising and control over urine and feces due to a decline in the autonomic response.
There are two types: rapid-sys movement (REM) and slow-wave sleep (non-REM). REM and non-REM cycles are both present throughout the sleep cycle. Non-REM sleep is believed to be the time for physiological recovery.
While the amount of sleep time does not change with age, the ratio of REM to non-REM sleep also changes. This results in fewer periods that are restorative nonREM. People over 60 complain about difficulty falling asleep or staying asleep.
A general term for brain disorders such as Dementia that cause memory loss, intellectual defects, behavior problems, and other signs and symptoms of mental deterioration is Dementia.
The most common form is Alzheimer’s disease. This disease affects 10% of those over 65 and 40% of those over 85. Alzheimer’s disease is progressive, and there are at least three stages.
Stage 1 symptoms include impaired recent memory, spatial disorientation, or a decrease in spontaneous emotional reactions. Stage two is when the patient begins to lose higher learning functions, such as reading, writing, and calculating.
The patient will lose their ability to track time and become confused. Eventually, the person may be unable to recognize family members.
The final stage of Alzheimer’s disease is when the patient experiences seizures and loses the ability to speak. Although the cause of Alzheimer’s is not known, it is known that Alzheimer’s patients experience brain accumulations. These proteins are also known as plaques. They interfere with normal brain function.
Non-Alzheimer Dementia is characterized by cognitive and behavioral changes that resemble Alzheimer’s Disease but are not progressive.
Multi-infarction dementia can be described as multiple mini-strokes that cause brain damage in small areas. Mini-strokes can cause progressive brain damage and may not be recognized by the person who is suffering. If strokes are not treated, the patient may develop Alzheimer’s-like symptoms.
Parkinson’s disease, a disorder of basal nuclei in the substantia nigra, is an example of these pathways’ indirect and direct effects. Parkinson’s disease results from neurons dying in the substantia-nigra pars compact. These neurons release dopamine to the striatum.
The modulatory effect of these neurons blocks the indirect pathway, so the basal nuclei remain in the indirect pathway without activating the direct pathway. The direct pathway increases cortical movement commands.
The hypokinetic disorder is a form of Parkinson’s disease that results from an increase in activity in the indirect pathway. Parkinson’s disease, also known as neurodegenerative, is a condition in which neurons are lost and cannot be replaced.
There is no cure. The treatment for Parkinson’s disease focuses on increasing the dopamine levels within the striatum. The most common method of increasing dopamine levels in Parkinson’s disease is to provide L-DOPA. This is an amino acid that acts as a precursor for the neurotransmitter Dopamine.
It can also cross the blood-brain border. The precursor levels can be increased, which means that the remaining cells in the substantial nigra pars compacta can make more neurotransmitters and produce a greater amount.
As time passes, L-DOPA treatment may become less effective. It can also cause an increase in dopamine levels, which can lead to psychosis and schizophrenia.
A stroke or cerebrovascular accident is a common form of aging dysfunction and is often mistakenly referred to as Dementia. It affects the brain. When a blood vessel that supplies the brain becomes blocked or ruptured, the disease begins in the cardiovascular system.
This causes blood to stop flowing to certain areas of the brain. It can lead to brain damage and even permanent disability. Large strokes may cause paralysis, Dementia, or even death. Individuals 65 years old and older have higher death rates.
How Does Age Affect Brain Function?
Intellectual ability can be maintained throughout one’s life if there is no disease. The gradual loss of neurons, neurotransmitter depletion, and slowing nerve conduction can lead to slower information processing.
This can lead to older people taking longer to complete tasks and experiencing the functional brain changes described below.
Memory that is episodic and short-term
A loss of episodic and short-term memory is the first sign of brain aging. The loss of short-term memories in the absence or presence of Dementia does not affect the ability to live a normal life, such as cooking.
Still, it can cause inconveniences like forgetting an item on the shopping list. Many older people experience a gradual decline in episodic memory, which can recall autobiographical events, their sequence, and their timings. (Fjell and al., 2014).
Word and verbal skills
Although verbal communication skills are generally strong throughout life (Park & Reuter-Lorenz 2009), people older than 70 may experience difficulty using words or recalling them.
The ability to name common objects quickly is usually stable until the age of 70. However, it declines as we get older (Harada and co-authors, 2013).
A slowing of reaction time is caused by the progressive loss of neurons, reduced impulse velocity, and minor changes to the spinal cord (Spirduso 1995). This can lead to problems, especially when fast reactions are required (e.g., to move out of the way for oncoming traffic).
Respectively around 22% and 28% of men over 65 years old are affected by depression in England. This number is even higher in care homes, with 40% of residents suffering from depression (Age UK 2017, 2017).
It is difficult to tell if depression in an older person is a normal side effect of aging or a result of chemical imbalances in depressions that affect younger people.
The levels of neurotransmitters that lift mood, particularly serotonin, decrease with age which can lead to depression symptoms (Fidalgo and colleagues 2013, 2013).
According to the Royal College of Psychiatrists, more than 85% of older depressed people do not receive any help from the NHS (Age UK 2017, 2017). Many depression symptoms can mimic Dementia (pseudodementia), which can cause great anxiety.
Overall, older people are less likely to have emotional outbursts as compared to younger people. This could be due to the relative stability of brain regions that are closely linked to emotions.
Studies of the amygdalae, which are involved in emotional reactions and impulsive behaviors, show little evidence of shrinkage or atrophy.
This is in contrast to other brain regions. The amygdalae appear to maintain most of their functional activity even in old age (Mather 2016).
Neuroactive drugs like antidepressants or neuroleptics that reduce the total neural mass can be more effective in older adults. Adult doses may cause confusion or delirium and should be adjusted.
How Does Aging Affect The Nervous System?
Your brain and nervous system undergo natural changes as you age. Atrophy occurs when the brain and spinal cord lose nerve cells. Nerve cells can transmit messages slower than usual.
As nerve cells die, waste products and other chemicals like beta-amyloid may build up in brain tissue. Plaques and tangles can form in the brain as a result. Nerve tissue can also become fatty brown from lipofuscin.
Your senses may be affected by nerve damage. It is possible to have decreased or lost sensations. This can lead to safety and movement problems.
Aging is normal. These changes may not be the same for everyone. Some people experience many changes in their brain tissue and nerves. Some people experience very few changes. These changes do not always have an impact on your ability to think.
Our nervous system is affected by our daily influences to protect and maintain a better nervous system; let’s live healthy and happy every day. We hope that our information can help you learn more important to protect your nervous system better.