THOUGHTS AND COMMENTARY
A Book Excerpt From
The Road to Neuroplasticity and Change to Heal Trauma, Improve Cognitive Capacity and Maximize Performance
I have been working on a book on neuroscience that is an easy way to understand the power of your brain, your mind and the thoughts that drive your creativity, insight and intelligence. The most powerful fact about the brain is the concept of neuroplasticity or the brain’s ability to change structurally to grow, evolve and increase it’s capabilities.
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> READ MORE ABOUT NEUROPLASTICITY
THE ADHD BRAIN
Unravel the ADHD Brain - Home
See Also:
Intro to the Brain and the Power of the Mind
See Also:
Intro to the Brain and the Power of the Mind
- Structure and Composition of Your Brain
- Strange & Interesting Facts on the Brain
- Hormones and Neurotransmitters
- The Role of Dopamine
- The Power of Thought - Neuroplasticity
- The Brain and Emotion
- Neuroscience Glossary
The Changing Brain
Researchers discovered that brains have neuroplasticity (brain structure can change). The brain retains this ability to change from birth to old age. ADHD brains that have deficits in one area will rewire themselves to accomplish a task. Meditation, for example, changes the brain. For a study researchers worked with people who never meditated before and one group participated in a eight-week mindfulness based stress reduction program. The structural changes were seen in the posterior cingulate, which produces mind wandering and self-awareness. Another change was in the left hippocampus which assists in learning, cognition, memory, and emotional regulation.
MRI studies on people with ADHD suggest that the long-term treatment with stimulants like amphetamines or methylphenidate, decreases abnormalities in brain structure and function and improves function in several parts of the brain, including the right caudate nucleus of the basal ganglia.
Studies have shown that the ADHD brain contains the following structural abnormalities
The frontal lobes carry out many critical functions, some considered executive functions: they include being able to focus your attention, maintain focus, switch among tasks, filter out distractions, and impulse control. Executive function includes the ability to weigh the probable outcomes of your behavior and then make high-level decisions about how you will behave.
Several studies have determined a smaller prefrontal cortex and basal ganglia plus a decrease in volume of the posterior inferior vermis of the cerebellum. Because of these structural differences the person’s focus and attention is affected.
One study published in 2010 found that children with ADHD do not have the same connections between the frontal cortex of the brain and visual processing area. This means that the ADHD brain processes information differently than a non-ADHD brain.
A study of cortical thickness in adults with ADHD found that adults with ADHD had significant thinning in the cortical neural network associated with attention, which primarily involved the right frontal and parietal lobes, compared with adults without ADHD.
A new international study measured differences in the brain structure of 1,713 people with a diagnosis of ADHD and 1,529 people without, all aged between four and 63 years old. All 3,242 people had an MRI scan to measure brain volume and the size of seven regions of the brain that were thought to be linked to ADHD (the pallidum, thalamus, caudate nucleus, putamen, nucleus accumbens, amygdala, and hippocampus.) It was found that volume the overall brain and five of the regions were smaller in people with ADHD (the caudate nucleus, putamen, nucleus accumbens, amygdala and hippocampus).
The ADHD brain has been found to have:
The Prefrontal cortex has been shown to have dysfunction. The prefrontal cortex controls emotional responses, behavior and judgment, which decides on the appropriateness of different actions, and of course, attention to the present task which enables individuals without ADHD to execute routine tasks without deliberate and focused attention to each step of the task. It is the part which plans, initiates and perfects actions as well as executing corrections, averting roadblocks by alternative actions, and enabling concentration on the task at hand. The basal ganglia regulates impulsive behavior so as to prevent unwarranted automatic responses to stimuli. Dysfunction of the prefrontal cortex results in a lack of alertness, shortened attention span, and decreased efficiency of working or short-term memory, difficulty in initiating and sustaining activities, and being unable to distinguish and avoid unnecessary or distracting activities.
Underactive frontal and parietal networks which regulate execution of actions and attention have been shown produce poor attention or induce hyperactivity. Additionally, there are overactive visual and dorsal attention networks as well as the default mode network.
MATURATION
Parts of the ADHD brain mature at a slower pace (approximately one to three years) and never reach the maturity of a person who does not have ADHD. Scans and other neuro-imaging research have shown that the brains of children with ADHD mature more slowly than do those of children without the disorder.
In a (MRI) study, children and adolescents with ADHD exhibited delays in cortical maturation versus typically developing controls. Delays were most prominent in prefrontal regions, which are important for control of cognitive processes, including attention and motor planning.
There is an apparent lack of ability to engage the the anterior cingulate cortex in ADHD brains.
BRAIN AND BRAIN REGIONS
Using MRIs, one study examined children with and without ADHD over a 10-year period. They found that brain size was different between the two groups. Children with ADHD had smaller brains by about 3 percent.
In children with ADHD, several brain regions and structures are smaller than neurotypical brains. This includes the pre-frontal cortex, striatum, basal ganglia, and cerebellum).
Researchers have discovered that the amygdala and hippocampus are smaller in the brains of people with ADHD. These areas are responsible for emotional processing and impulsivity and had previously not been definitively connected to ADHD.
In a study 49 adolescents diagnosed with ADHD at age 16 were examined for brain structure and memory function in young adulthood (between 20 to 24 years old), compared to a control group of 34 young adults. Results showed that the group diagnosed in adolescence had a decrease in brain volume as adults. This lead to to poor memory function, Researchers also saw a reduction in gray matter in the caudate nucleus which is the brain region that integrates information across different parts of the brain to support cognitive functions and memory.
In ADHD, the daydreaming brain doesn’t quiet down when the attention circuits turn on. Weak connections between control centers and the DMN cause an inability to modulate DMN activity. Studies have found that the balance between the cognitive control network and the DMN is either reduced, or absent an the ADHD brain.
DECREASED BLOOD FLOW
The front of the brain behind the forehead is the frontal lobe. The frontal lobe helps you to organize, plan, pay attention, and make decisions. The frontal lobe is the area of the brain responsible for problem solving, memory, language, motivation, impulse control, and decision making. There is decreased blood flow to certain prefrontal areas. Decreased blood flow indicates decreased brain activity. The prefrontal area of the brain affects executive functionsand are responsible for many tasks including planning, organizing, paying attention, remembering, and emotional reactions.
NEUROTRANSMITTERS ARE CHEMICAL MESSENGERS
Neurotransmitters are chemical messengers. They are a central part of the communication system between the brain and the rest of the body. Neurotransmitters carry messages between nerve cells (or neurons) in the brain and the rest of the central nervous system. The central nervous system is the means by which the brain communicates with the rest of the body. This happens with the spinal column. Since many messages originate at the Neurotransmitter level, they are central to understanding brain disorders.
The brain is a busy communication network with messages relayed from one neuron (brain cell) to the next. There is a gap between neurons called a synapse. In order to pass a message the synapse needs to be filled with a Neurotransmitter. Neurotransmitters are chemical messengers and each one is responsible for different functions.
The Neurotransmitters act like a key and the receptor sites act like a lock. It takes the right key to open specific locks. If the neurotransmitter is able to work on the receptor site, it triggers changes in the receiving cell.
Neurotransmitters play a major role in everyday life and functioning. Scientists do not yet know exactly how many neurotransmitters exist, but more than 100 chemical messengers have been identified.
Some Neurotransmitters such as acetylcholine and dopamine can create both excitatory and inhibitory effects depending upon the type of receptors that are present.
NEUROTRANSMITTERS AFFECTED IN THE ADHD BRAIN
See Also:
Hormones and Neurotransmitters
The Role of Dopamine
Dopamine and Norepinephrine affect:
Patients with predominantly inattentive ADHD show changes to their norepinephrine transporter gene, which affects norepinephrine levels in their brains. Patients with predominantly hyperactivity-impulsive ADHD show changes to their dopamine transport gene, thus affecting dopamine levels in the brain.
THE ROLE OF DOPAMINE
Individuals with ADHD seem to have an excessively efficient dopamine removal system. They have a higher concentration of dopamine transporters called re-uptake inhibitors. When dopamine is removed too quickly, it doesn't have sufficient time to exert its effect. Researchers now believe that this overly-efficient transporter process may help to explain some ADHD symptoms.
For example, Ritalin® is a commonly used drug for ADHD. It is a stimulant medication that blocks dopamine transporters. It slows the removal of dopamine after it is released. Researchers theorize that Ritalin helps reduce ADHD symptoms by giving dopamine more time to act on the cells. This creates a better ability to manage mood, motivation, and attention.
Dopamine helps control the brain’s reward and pleasure center. Stimulant medications help ADHD because they encourage more dopamine to be produced or keep dopamine in the synapses longer.
Maturation of dopaminergic neural pathways appears to be delayed in children and adolescents with ADHD. Levels of available dopamine receptor and transporter molecules are typically lower in some parts of the brain in adults with ADHD.
Research on dopamine results from the radioactive tracer raclopride that is injected into the body and attaches to empty dopamine receptors. Raclopride binding has been found to be higher in ADHD. We can see that dopamineactivity levels are low. Raclopride will drop when Stimulant medications are used. These stimulants normalize dopamine function .
NOREPINEPHRINE
ADHD brains have reduced levels of the Neurotransmitter norepinephrine. Norepinephrine is connected with dopamine. Norepinephrine is a catecholamine synthesized by dopamine. Catecholamines sometimes function as a hormone. Other times they function as a Neurotransmitter. Hormones are messengers that communicate with both the brain and the rest of the body through the blood stream. Some chemicals operate as both a neurotransmitter and a hormone. When norepinephrine functions as a stress hormone, it affects attention. Some neurotransmitters affect the release of certain hormones.
Norepinephrine is released into the blood as a stress hormone when the brain perceives that a stressful event has occurred. As part of the body's response to stress, norepinephrine affects the way the brain pays attention and responds to events. It can also do the following: increase heart rate, trigger the release of glucose (sugar) into the blood, and Increase blood flow to muscles,
As a Neurotransmitter in the central nervous system, norepinephrine increases alertness and arousal, and speeds reaction time. Norepinephrine has been shown to play a role in a person's mood and ability to concentrate.
SEROTONIN
Serotonin transporter gene polymorphisms are also known to be associated with different modes of response to treatment. In addition, glutamate levels may be lower in adults with ADHD, which could be responsible for the neurotransmitter abnormalities. This causes dysfunctional neural networking in the above parts of the brain. Serotonin influences mood, social behavior, sleep, and memory. Low levels of serotonin may impair these functions.
Researchers discovered that brains have neuroplasticity (brain structure can change). The brain retains this ability to change from birth to old age. ADHD brains that have deficits in one area will rewire themselves to accomplish a task. Meditation, for example, changes the brain. For a study researchers worked with people who never meditated before and one group participated in a eight-week mindfulness based stress reduction program. The structural changes were seen in the posterior cingulate, which produces mind wandering and self-awareness. Another change was in the left hippocampus which assists in learning, cognition, memory, and emotional regulation.
MRI studies on people with ADHD suggest that the long-term treatment with stimulants like amphetamines or methylphenidate, decreases abnormalities in brain structure and function and improves function in several parts of the brain, including the right caudate nucleus of the basal ganglia.
Studies have shown that the ADHD brain contains the following structural abnormalities
- Lower grey matter density
- In children there is a general reduction of volume in various brain structures, especially in the left-sided prefrontal cortex.
- The posterior parietal cortex shows thinning
- The volume of the accumbens, amygdala, caudate, hippocampus, and putamen appears smaller in ADHD brains.
- White matter abnormalities
- Reduced total brain volume and volume of some brain structures
- Cortical differences
- Delayed cortical maturation in children/adolescents
- Reduced cortical thickness in adults.
The frontal lobes carry out many critical functions, some considered executive functions: they include being able to focus your attention, maintain focus, switch among tasks, filter out distractions, and impulse control. Executive function includes the ability to weigh the probable outcomes of your behavior and then make high-level decisions about how you will behave.
Several studies have determined a smaller prefrontal cortex and basal ganglia plus a decrease in volume of the posterior inferior vermis of the cerebellum. Because of these structural differences the person’s focus and attention is affected.
One study published in 2010 found that children with ADHD do not have the same connections between the frontal cortex of the brain and visual processing area. This means that the ADHD brain processes information differently than a non-ADHD brain.
A study of cortical thickness in adults with ADHD found that adults with ADHD had significant thinning in the cortical neural network associated with attention, which primarily involved the right frontal and parietal lobes, compared with adults without ADHD.
A new international study measured differences in the brain structure of 1,713 people with a diagnosis of ADHD and 1,529 people without, all aged between four and 63 years old. All 3,242 people had an MRI scan to measure brain volume and the size of seven regions of the brain that were thought to be linked to ADHD (the pallidum, thalamus, caudate nucleus, putamen, nucleus accumbens, amygdala, and hippocampus.) It was found that volume the overall brain and five of the regions were smaller in people with ADHD (the caudate nucleus, putamen, nucleus accumbens, amygdala and hippocampus).
The ADHD brain has been found to have:
- Lower grey matter density
- White matter abnormalities
- Reduced total brain volume and volume of some brain structures
- Cortical differences with delayed cortical maturation in children/adolescents
- Reduced cortical thickness in adults.
The Prefrontal cortex has been shown to have dysfunction. The prefrontal cortex controls emotional responses, behavior and judgment, which decides on the appropriateness of different actions, and of course, attention to the present task which enables individuals without ADHD to execute routine tasks without deliberate and focused attention to each step of the task. It is the part which plans, initiates and perfects actions as well as executing corrections, averting roadblocks by alternative actions, and enabling concentration on the task at hand. The basal ganglia regulates impulsive behavior so as to prevent unwarranted automatic responses to stimuli. Dysfunction of the prefrontal cortex results in a lack of alertness, shortened attention span, and decreased efficiency of working or short-term memory, difficulty in initiating and sustaining activities, and being unable to distinguish and avoid unnecessary or distracting activities.
Underactive frontal and parietal networks which regulate execution of actions and attention have been shown produce poor attention or induce hyperactivity. Additionally, there are overactive visual and dorsal attention networks as well as the default mode network.
MATURATION
Parts of the ADHD brain mature at a slower pace (approximately one to three years) and never reach the maturity of a person who does not have ADHD. Scans and other neuro-imaging research have shown that the brains of children with ADHD mature more slowly than do those of children without the disorder.
In a (MRI) study, children and adolescents with ADHD exhibited delays in cortical maturation versus typically developing controls. Delays were most prominent in prefrontal regions, which are important for control of cognitive processes, including attention and motor planning.
There is an apparent lack of ability to engage the the anterior cingulate cortex in ADHD brains.
BRAIN AND BRAIN REGIONS
Using MRIs, one study examined children with and without ADHD over a 10-year period. They found that brain size was different between the two groups. Children with ADHD had smaller brains by about 3 percent.
In children with ADHD, several brain regions and structures are smaller than neurotypical brains. This includes the pre-frontal cortex, striatum, basal ganglia, and cerebellum).
Researchers have discovered that the amygdala and hippocampus are smaller in the brains of people with ADHD. These areas are responsible for emotional processing and impulsivity and had previously not been definitively connected to ADHD.
In a study 49 adolescents diagnosed with ADHD at age 16 were examined for brain structure and memory function in young adulthood (between 20 to 24 years old), compared to a control group of 34 young adults. Results showed that the group diagnosed in adolescence had a decrease in brain volume as adults. This lead to to poor memory function, Researchers also saw a reduction in gray matter in the caudate nucleus which is the brain region that integrates information across different parts of the brain to support cognitive functions and memory.
In ADHD, the daydreaming brain doesn’t quiet down when the attention circuits turn on. Weak connections between control centers and the DMN cause an inability to modulate DMN activity. Studies have found that the balance between the cognitive control network and the DMN is either reduced, or absent an the ADHD brain.
DECREASED BLOOD FLOW
The front of the brain behind the forehead is the frontal lobe. The frontal lobe helps you to organize, plan, pay attention, and make decisions. The frontal lobe is the area of the brain responsible for problem solving, memory, language, motivation, impulse control, and decision making. There is decreased blood flow to certain prefrontal areas. Decreased blood flow indicates decreased brain activity. The prefrontal area of the brain affects executive functionsand are responsible for many tasks including planning, organizing, paying attention, remembering, and emotional reactions.
NEUROTRANSMITTERS ARE CHEMICAL MESSENGERS
Neurotransmitters are chemical messengers. They are a central part of the communication system between the brain and the rest of the body. Neurotransmitters carry messages between nerve cells (or neurons) in the brain and the rest of the central nervous system. The central nervous system is the means by which the brain communicates with the rest of the body. This happens with the spinal column. Since many messages originate at the Neurotransmitter level, they are central to understanding brain disorders.
The brain is a busy communication network with messages relayed from one neuron (brain cell) to the next. There is a gap between neurons called a synapse. In order to pass a message the synapse needs to be filled with a Neurotransmitter. Neurotransmitters are chemical messengers and each one is responsible for different functions.
The Neurotransmitters act like a key and the receptor sites act like a lock. It takes the right key to open specific locks. If the neurotransmitter is able to work on the receptor site, it triggers changes in the receiving cell.
Neurotransmitters play a major role in everyday life and functioning. Scientists do not yet know exactly how many neurotransmitters exist, but more than 100 chemical messengers have been identified.
- Excitatory neurotransmitters: These types of neurotransmitters have excitatory effects on the neuron, meaning they increase the likelihood that the neuron will fire an action potential. Some of the major excitatory neurotransmitters include epinephrine and norepinephrine.
- Inhibitory neurotransmitters: These types of neurotransmitters have inhibitory effects on the neuron; they decrease the likelihood that the neuron will fire an action potential. Some of the major inhibitory neurotransmitters include serotonin and gamma-aminobutyric acid (GABA).
- Modulatory neurotransmitters: These neurotransmitters are capable of affecting a larger number of neurons at the same time. They also influence the effects of other chemical messengers. Neuromodulators diffuse across a larger area and are slow-acting.
Some Neurotransmitters such as acetylcholine and dopamine can create both excitatory and inhibitory effects depending upon the type of receptors that are present.
NEUROTRANSMITTERS AFFECTED IN THE ADHD BRAIN
- Dopamine produces feelings of pleasure and is usually inhibitory. Glycine is used by neurons in the spinal cord and is inhibitory.
- Seratonin is involved in many functions including but not limited to mood and appetite, and is inhibitory in pain pathways.
- Norepinephrine is part of the flight or fight response, and is usually excitatory.
See Also:
Hormones and Neurotransmitters
The Role of Dopamine
Dopamine and Norepinephrine affect:
- The frontal cortex (affecting attention executive function, organization) gives us the ability to plan and organize while focusing on and identifying internal and external stimuli.
- A deficiency in the basal ganglia, which regulates communication between different parts of the brain, can interrupt brain communication and cause information to “short-circuit." This results in inattention or impulsivity.
- The reticular activating system, which can be characterized as the gateway to our consciousness. It is the part of the brain that allows us to determine what to focus on and what to tune out as white noise. A deficiency here can cause inattention impulsivity or hyperactivity.
Patients with predominantly inattentive ADHD show changes to their norepinephrine transporter gene, which affects norepinephrine levels in their brains. Patients with predominantly hyperactivity-impulsive ADHD show changes to their dopamine transport gene, thus affecting dopamine levels in the brain.
THE ROLE OF DOPAMINE
Individuals with ADHD seem to have an excessively efficient dopamine removal system. They have a higher concentration of dopamine transporters called re-uptake inhibitors. When dopamine is removed too quickly, it doesn't have sufficient time to exert its effect. Researchers now believe that this overly-efficient transporter process may help to explain some ADHD symptoms.
For example, Ritalin® is a commonly used drug for ADHD. It is a stimulant medication that blocks dopamine transporters. It slows the removal of dopamine after it is released. Researchers theorize that Ritalin helps reduce ADHD symptoms by giving dopamine more time to act on the cells. This creates a better ability to manage mood, motivation, and attention.
Dopamine helps control the brain’s reward and pleasure center. Stimulant medications help ADHD because they encourage more dopamine to be produced or keep dopamine in the synapses longer.
Maturation of dopaminergic neural pathways appears to be delayed in children and adolescents with ADHD. Levels of available dopamine receptor and transporter molecules are typically lower in some parts of the brain in adults with ADHD.
Research on dopamine results from the radioactive tracer raclopride that is injected into the body and attaches to empty dopamine receptors. Raclopride binding has been found to be higher in ADHD. We can see that dopamineactivity levels are low. Raclopride will drop when Stimulant medications are used. These stimulants normalize dopamine function .
NOREPINEPHRINE
ADHD brains have reduced levels of the Neurotransmitter norepinephrine. Norepinephrine is connected with dopamine. Norepinephrine is a catecholamine synthesized by dopamine. Catecholamines sometimes function as a hormone. Other times they function as a Neurotransmitter. Hormones are messengers that communicate with both the brain and the rest of the body through the blood stream. Some chemicals operate as both a neurotransmitter and a hormone. When norepinephrine functions as a stress hormone, it affects attention. Some neurotransmitters affect the release of certain hormones.
Norepinephrine is released into the blood as a stress hormone when the brain perceives that a stressful event has occurred. As part of the body's response to stress, norepinephrine affects the way the brain pays attention and responds to events. It can also do the following: increase heart rate, trigger the release of glucose (sugar) into the blood, and Increase blood flow to muscles,
As a Neurotransmitter in the central nervous system, norepinephrine increases alertness and arousal, and speeds reaction time. Norepinephrine has been shown to play a role in a person's mood and ability to concentrate.
SEROTONIN
Serotonin transporter gene polymorphisms are also known to be associated with different modes of response to treatment. In addition, glutamate levels may be lower in adults with ADHD, which could be responsible for the neurotransmitter abnormalities. This causes dysfunctional neural networking in the above parts of the brain. Serotonin influences mood, social behavior, sleep, and memory. Low levels of serotonin may impair these functions.
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View Me on Twitter @kairosoflife
See Creativity Chaos - a Creativity Blog by Kai
About | Reprints & Copyrights | Home
© 2019-2020 Copyright Starlight Poetry
VIEW FULL SITE DIRECTORY