The brain and diseases associated with it
It turns out that depression reduces activity in some areas of the brain; with migraines, the concentration of gray matter decreases, and alcohol completely kills nerve cells.
Post Traumatic Stress Disorder
When a person goes through trauma, their brain triggers the ancient fight-or-flight response. Previously, this helped to escape from a mammoth or defeat a saber-toothed tiger. Now other dangers play the role of tigers – but a person habitually reacts in the same way as many thousands of years ago.
The stress passes, the need for brain reactions disappears – and most people return to their usual rhythm of life. But some fall into a condition called post-traumatic stress disorder (PTSD). It causes the amygdala—the part of the brain that controls emotions—to be too active. This reduces the activity of another part of the brain – the prefrontal cortex, which is responsible for decision-making. And the hippocampus, which “records” memories, also suffers, and a person’s memory worsens.
An ischemic stroke occurs when blood flow to any part of the brain is cut off. At the same time, those departments that have lost nutrition suffers. If the left hemisphere is damaged, a person develops paralysis and paresis on the right side of the body if it’s right, and vice versa.
An aneurysm is a bulge in the wall of a vessel. As the aneurysm develops, it swells, fills with blood, sometimes ruptures, and leads to bleeding in the brain tissue and under its membranes. As a result, a hemorrhagic stroke develops, leading to disturbances in the functioning of internal organs and sensory organs.
Alcohol abuse affects all organs, but the brain suffers the most. A person develops blurred vision, speech slurred, movements become discoordination, and memory impaired. With prolonged use of alcohol, the state of the brain progressively worsens. Studies have shown that alcoholism reduces the hippocampus – the area of the brain responsible for learning and remembering information.
Studies show that people with schizophrenia have slightly different brain structures. They have a smaller volume of gray and white matter, due to which all the key processes in the body occur. Interestingly, as schizophrenia progresses, the proportion of gray matter that helps process information first decreases. Gradually, the volume of white matter also decreases – that part of the brain where this information is stored and distributed.
In the brain of a healthy person, a connection has been established between neurons – nerve cells. They send signals to each other using complex chemical reactions. In Alzheimer’s disease, this connection is disrupted. Scientists believe this occurs due to the accumulation of two proteins – tau and amyloid. They create clusters that interfere with the movement of nerve impulses through neurons.
In multiple sclerosis, the immune system does not work quite correctly. It attacks its cells – the nerve centers in the brain and spinal cord. This increases the production of leukocytes – white blood cells. Leukocytes damage myelin – a substance that is part of the sheath of nerve fibers. As a result, the nerves are destroyed, and they cannot fully perform their tasks. Such changes lead to the appearance of characteristic symptoms of multiple sclerosis – memory loss, hand tremors, and visual impairment.
In people with migraines, the conduction of impulses in the brain is disrupted. Some of their nerve fibers overreact to common stimuli, such as bright lights or loud sounds. This triggers a chain of complex biochemical reactions, as a result of which the vessels of the brain constrict, and a severe headache appears. Over time, people with migraines experience a decrease in the amount of gray and white matter.
Even a small concussion of the brain leads to damage to its tissues. And this is not only a physical tissue tear or bruise. Trauma upsets the balance of chemicals in the brain, damages nerve cells, and provokes inflammation. Multiple concussions and bruises of the brain can lead to significant damage and loss of some central nervous system functions. Memory impairment decreased performance, and inability to concentrate are possible consequences.
Depression is not just a bad mood but a serious illness. And it affects not only the emotional sphere but also other aspects of the personality. Studies have shown that depression reduces the activity of the brain’s prefrontal lobes, which are associated with the ability to reason logically.
It has also been noted that if depression has existed for more than ten years, damage to the brain’s prefrontal lobes reaches 30%. This, in turn, leads to memory impairment and associated personality disorders.
Bipolar affective disorder
Studies have shown that bipolar disorder has an imbalance of neurotransmitters and special substances in the brain. These substances are responsible for transmitting signals between nerve cells and affect various processes – performance, attention, memory, and sleep. For example, if too much of the neurotransmitter adrenaline, the person may go into the manic stage. And if too little, there will be depression.
Studies show that attention deficit/hyperactivity disorder causes a decrease in the proportion of gray and white matter in the brain. And the principle of operation of the network of nerve cells that send signals to various parts of the brain is also changing. These brain changes are believed to lead to inattention and hyperactivity.