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. We do this with cognitive training and surprisingly, mindfulness meditation. The brain can also heal from trauma as seen with the comparison of brain scans done on combat war veterans suffering from PTSD. Neuroscience is a remarkable wonder that we haven’t even truly begun to comprehend.
> READ MORE ABOUT NEUROPLASTICITY
> READ MORE ABOUT NEUROPLASTICITY
AVAILABLE NOW!
A complete PDF guide to this section of my book is available for download now. If you are interested in reading it please email me to request a copy.
A complete PDF guide to this section of my book is available for download now. If you are interested in reading it please email me to request a copy.
HEALING THE PTSD MIND
HEALING THE PTSD MIND - HOME
The Neuroscience Behind Trauma & PTSD
Practicing Self Care
See Also:
Introduction to the Brain
Structure and Composition of the Brain
Glossary of Neuroscience
The Neuroscience Behind Trauma & PTSD
Practicing Self Care
- Debunking the Myths of PTSD
- Managing Intrusive Thoughts
- Dealing With Triggers
- Handling Flashbacks and Nightmares
- Coping With Suicidal Thoughts
See Also:
Introduction to the Brain
Structure and Composition of the Brain
Glossary of Neuroscience
STARLIGHT POETRY BY KAI
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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
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The brain is the command center that controls all functions of the body, interprets information from the outside world, and makes up the essence of the mind and soul. It drives intelligence, creativity, emotion, and memory.
The brain receives information through our five senses: sight, smell, touch, taste, and hearing. It assembles the messages our senses deliver and that information is stored in our memory. The brain commands our thoughts, memory and speech, allows movement of the arms and legs, and provides functionality for many organs within our body.
The central nervous system (CNS) is composed of the brain and spinal cord. The peripheral nervous system (PNS) is composed of spinal nerves that come from the spinal cord and cranial nerves that come from the brain.
The brain is composed of the cerebrum, cerebellum, and brainstem.
The cerebrum is divided into two halves: the right and left hemispheres. They are joined by fibers called the corpus callosum. These fibers transmit messages from one side to the other. Each hemisphere controls the opposite side of the body.
Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in most people.
Lobes of the brain
The cerebral hemispheres divides the brain into lobes. Each hemisphere has 4 lobes: frontal, temporal, parietal, and occipital. Each lobe may be divided into areas that serve very specific functions. There are relationships between the lobes of the brain and between the right and left hemispheres.
The cerebrum is divided into four lobes: frontal, parietal, occipital and temporal.
The Frontal lobe controls:
The Parietal lobe controls
The Occipital lobe controls
The Temporal lobe controls
PTSD affects the structure of the brain. The following terms define the areas affected.
Acetylcholine: Neurotransmitter found at the neuromuscular junction, within the autonomic nervous system, and the basal forebrain. Acetylcholine neurotransmission at the neuromuscular junction is essential for skeletal muscle activation. In the brain, acetylcholine is believed to play a key role in memory.
Adrenaline/Epinephrine: A catecholamine hormone or neurotransmitter. Epinephrine is produced by the adrenal gland and by neurons within the sympathetic nervous system. Epinephrine in the bloodstream acts to increase cardiac output (heart rate, blood pressure), dilate airways, and raise blood glucose levels.
Amygdala: Almond shaped brain region (one in each temporal lobe) that plays a role in decision-making and emotional processing. The amygdala participates in pain processing, reward, anger/rage, fear and anxiety.
Autonomic nervous system: Division of the peripheral nervous system that is outside of conscious control. The autonomic nervous system drives vegetative functions such as heart rate, respiration, and pupil dilation, among others. The autonomic nervous system is further divided into the parasympathetic and sympathetic nervous systems. These systems generally work antagonistically on various organs (i.e. one causes the opposite effect of the other). Lastly, the enteric nervous system is found along the gastrointestinal tract, which produces gastric motility and aids in digestion.
Basal ganglia: A collection of brain regions connected through complex circuitry of excitatory and inhibitory pathways. The basal ganglia participates in motivation, working memory, and decision-making behaviors. Damage to certain parts of the basal ganglia causes a range of movement disorders, from hypokinetic (Parkinson’s disease; substantia nigra pars compacta) to hyperkinetic (Huntington’s disease; stratum) disorders.
Brainstem: Collection of neurons and nerve fibers at the base of the brain and at the top of the spinal cord including the midbrain, the pons, and the medulla oblongata. The brainstem maintains consciousness, regulates the sleep/wake cycle, and 10 of the 12 cranial nerves originate in the brainstem.
Catecholamine: An organic molecule that contains a catechol group and a single amine group. In neuroscience, important catecholamines are epinephrine, norepinephrine, and dopamine.
Central nervous system: The brain and spinal cord, the optic nerve, the olfactory nerves, and the retina. The central nervous system is so named as to distinguish it from the peripheral nervous system. Most regions of the central nervous system are protected by the blood brain barrier, while the peripheral nervous system is not.
Cerebellum: The second-largest brain structure after the cerebrum. It is located below the rear of the cerebrum and behind the pons/brainstem. While the cerebrum is directly responsible for movement, the cerebellum improves coordination and the precision of movements. The cerebellum is important for fine motor movements, equilibrium, and maintaining posture. The cerebellum also participates in motor learning.
Cerebral cortex: Outer portion of the cerebrum that contains the cell bodies of neurons in the brain (gray matter). The thickness of a person’s cerebral cortex roughly correlates with their intelligence quotient (IQ). As the cortex thins due to aging or neurodegenerative diseases, a person’s cognitive capacity diminishes.
Cerebrum: The largest part of the brain. It contains the cortex and subcortical structures. The cerebrum specifically does not include the cerebellum or the brainstem. The cerebrum is responsible for executive function, sensory processing, language, learning and memory formation, and voluntary movement. The cerebrum is separated into two hemispheres, which are connected by the corpus callosum.
Cognition: A term that broadly applies to the mental processes of thinking, learning, and memory. Cognition generally applies to higher mental function, rather than autonomic and automatic processes. For example, actively acquiring new knowledge is a form of cognition, but emotional reactions to events or processes that drive heart rate and breathing rate are not.
Corpus callosum: The main connection between the right and left hemispheres of the brain. The corpus callosum is comprised of nerve fibers that transmit information between cerebral hemispheres.
Cortisol: Steroid hormone produced by the adrenal glands in response to stressors such as infection, sleep deprivation, or trauma. Normal levels of cortisol are important for maintaining glucose levels and blood pressure. Chronically elevated levels of cortisol, on the other hand, can suppress the immune system, increase body weight, and interfere with cognition, among other effects.
Dopamine: A catecholamine neurotransmitter. Dopamine is produced in many neuron groups in the brain, though it is found in particularly high concentrations in the substantia nigra and in the ventral tegmental area. The role dopamine plays depends on its location. For example, dopamine in the mesolimbic pathway creates a sensation of motivation, desire, and reward. Abnormal stimulation in this region may also lead to addiction or hallucinations. On the other hand, dopamine in the nigrostriatal pathway participates in motor control.
Endorphins: Natural (endogenous) neuropeptide hormones are released in response to pain or vigorous aerobic exercise and bind to/act on opioid receptors. Like exogenous opioids, endorphins block pain signals and pain processing, which reduces the perception of pain. Endogenous endorphins can create a mild euphoria, just as exogenous opioids can.
Executive Function: Executive function includes higher-level cognitive abilities including abstract thinking, complex task planning, emotional inhibition, impulse control, and problem solving. Executive function is required to plan and initiate complex tasks, rather than more mundane or automatic behaviors.
Frontal Lobe: Front section of the cerebrum lying behind the forehead and extending back to the ears. The frontal lobe controls executive functioning, abstract thinking, decision-making, speech formation, and voluntary movements. A person’s personality mostly resides in the frontal lobe; damage to the frontal lobe can result in marked changes to personality causing anger, aggressive behavior, and social isolation.
Gamma-aminobutyric acid (GABA): The main inhibitory neurotransmitter in the central nervous system. GABA acting on GABA receptors on pre-and postsynaptic neurons hyperpolarizes neurons and makes them less likely to fire action potentials. Drugs that increase GABA activity such as benzodiazepines tend to reduce seizure potential (by reducing neuronal activity) and decrease anxiety.
Glutamate: The most abundant excitatory neurotransmitter in the central nervous system. Glutamate participates in excitatory neurotransmission in most neurons in the brain. Excessive glutamate neurotransmission may lead to excitotoxicity, which destroys neurons through excessive stimulation.
Glycine: Glycine is an inhibitory neurotransmitter found in the brain and the spinal cord. Glycine is also required along with glutamate to stimulate NMDA receptors, which is a major excitatory system in the brain. Thus, glycine has inhibitory and excitatory actions in the central nervous system.
Hippocampus: Structure within the medial temporal lobe of the brain and major component of the limbic system. The hippocampus participates in the consolidation of short-term memory into long-term memory, and participates in spatial memory. Damage to the hippocampus results in short-term memory loss, spatial memory loss, and disorientation. The hippocampus exhibits a phenomenon called long-term potentiation, which is considered a neural substrate for memory formation.
Histamine: In neuroscience, histamine primarily acts as a neuron modulator. Histamine receptor stimulation results in changes in acetylcholine, dopamine, norepinephrine, and serotonin release, and the release of certain peptides. Histamine is also a particularly potent modulator in the hypothalamus, and affects pain processing.
Hormone: A substance that is released by a gland to create a biological effect at another location in the body. For example, thyroid hormone is released by the thyroid gland in the neck to affect the metabolic activity of cells throughout the body. Hormone levels in the blood are tightly regulated under normal circumstances; abnormally high or low levels of hormones in the blood may cause a constellation of signs and symptoms.
Hypothalamus: Component of the limbic system located under the thalamus. It contains a number of nuclei with specific functions. The hypothalamus releases hormones and neuropeptides that act on the pituitary gland and/or other glands and tissues throughout the body. Once stimulated, the pituitary gland, in turn, releases hormones into the bloodstream. For example, the hypothalamus secretes thyrotropin-releasing hormone that acts on the anterior pituitary to release thyroid-stimulating hormone, which in turn stimulates the thyroid gland to release thyroid hormone.
Limbic system: A collection of brain structures including the amygdala, basal ganglia, cingulate gyrus, hippocampus, hypothalamus, and thalamus. The limbic system is responsible for integrating higher order functions (executive function, task planning) with lower order brain functions (emotional pain processing, emotional memory processing).
Locus Coeruleus: Brainstem nucleus that houses the brain’s densest concentration of norepinephrine-containing neurons. The locus coeruleus participates in arousal, attention, and memory, and it may also participate in normal and abnormal expressions of mood, alertness, and anxiety.
Neuron: A nerve cell. A nerve cell collects electrical and/or chemical input and, once conditions are met, can fire an action potential along its axon. The action potential causes the release of neurotransmitters into the synaptic cleft, which can then act on adjacent neurons. The human brain has about 100 billion neurons arranged in an astonishingly complex network.
Neuroplasticity/Plasticity: The process by which neurons, particularly in the brain, create and reorganize connections between cells to adapt to injury, environmental changes, or novel situations. Neuroplasticity explains how a person with brain injury can regain the ability to walk, as healthy regions of the brain adapt to take over the responsibilities of the injured region. Neuroplasticity also encompasses the changes that take place in the brain during learning and memory formation.
Noradrenaline/Norepinephrine: A catecholamine hormone or neurotransmitter. Norepinephrine is produced by three separate structures in the body, the adrenal gland, sympathetic nervous system ganglia, and locus coeruleus neurons in the brain. Norepinephrine acting in the systemic circulation or within the sympathetic nervous system increases heart rate and blood pressure, among other functions. In the brain, norepinephrine neurotransmission increases alertness, speed of action, and vigilance.
Occipital Lobe: Lower part of the cerebrum located at the back of the skull under the parietal lobe, behind the temporal lobe, and on top of the cerebellum. The occipital lobe is primarily involved in receiving and processing visual information. The occipital lobe compiles information from the visual pathways to create an integrated image from light that enters the eyes. The occipital lobe determines the visual attributes of vision including color, distance, and size, not only using this information to create vision but also to form visual memories.
Parietal Lobe: Top part of the cerebrum lying between the ears and the back of the skull. The parietal lobe is important for integrating sensory information influencing how we perceive information from the outside world. The parietal lobe is responsible for processing language, visual information, tactile stimulation, and visuospatial reasoning.
Peripheral nervous system: The nerves and ganglia that occur outside of the brain and spinal cord. With the exception of the optic nerves and olfactory nerves, the cranial nerves are also part of the peripheral nervous system. The peripheral nervous system is sometimes subdivided into the somatic nervous system and the autonomic nervous system. However, if it is unspecified, the peripheral nervous system indicates the somatic nervous system, which controls skeletal muscles and receives most sensory information.
Pituitary gland: Gland at the base of the brain under the hypothalamus. The pituitary gland is divided into anterior and posterior sections. The anterior pituitary gland produces growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, luteinizing hormone, and prolactin. The posterior pituitary produces oxytocin, vasopressin, and antidiuretic hormone. The hypothalamus stimulates the pituitary gland to release these hormones under certain circumstances.
Prefrontal cortex: The frontmost portion of the brain. The prefrontal cortex is responsible for complex task planning, decision-making, and appropriate social inhibition. Moreover, the prefrontal cortex is believed to generate a substantial portion of a person’s personality. The prefrontal cortex is critical for executive function and attention.
Serotonin: A monoamine neurotransmitter (aka 5-hydroxytryptamine). Serotonin in the brain is involved in mood, appetite, and sleep regulation. The primary source of serotonin in the brain is the raphe nuclei in the brainstem. Certain antidepressants (e.g. selective serotonin reuptake inhibitors) act by increasing serotonin neurotransmission.
Synapse: Anatomical area where two neurons interact with one another. At a synapse, a (presynaptic) neuron releases chemicals called neurotransmitters into the synaptic cleft, the space between two neurons. Neurotransmitters diffuse across the synaptic cleft and interact with receptors of the adjacent (postsynaptic) neuron. The neurotransmitter makes it more or less likely that the adjacent neuron will fire an action potential, depending on whether it is an excitatory or inhibitory neuron, respectively.
Temporal Lobe: Lower part of the brain that sits deep to the ears, extending from the temples back to the occipital cortex. The temporal lobe is responsible for processing auditory input and recognizing language. The temporal lobe also includes the hippocampus. Thus, the temporal lobe is important for long-term memory formation.
Thalamus: Brain structure that rests in the center of the brain below the corpus callosum that serves as a relay center of sensory information between the sensory organs and sensory cortices. All senses (except olfactory sensation) pass through the thalamus.
The brain receives information through our five senses: sight, smell, touch, taste, and hearing. It assembles the messages our senses deliver and that information is stored in our memory. The brain commands our thoughts, memory and speech, allows movement of the arms and legs, and provides functionality for many organs within our body.
The central nervous system (CNS) is composed of the brain and spinal cord. The peripheral nervous system (PNS) is composed of spinal nerves that come from the spinal cord and cranial nerves that come from the brain.
The brain is composed of the cerebrum, cerebellum, and brainstem.
- Cerebrum: is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement.
- Cerebellum: is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance.
- Brainstem: acts as a relay connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing.
The cerebrum is divided into two halves: the right and left hemispheres. They are joined by fibers called the corpus callosum. These fibers transmit messages from one side to the other. Each hemisphere controls the opposite side of the body.
Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in most people.
Lobes of the brain
The cerebral hemispheres divides the brain into lobes. Each hemisphere has 4 lobes: frontal, temporal, parietal, and occipital. Each lobe may be divided into areas that serve very specific functions. There are relationships between the lobes of the brain and between the right and left hemispheres.
The cerebrum is divided into four lobes: frontal, parietal, occipital and temporal.
The Frontal lobe controls:
- Personality, behavior, emotions
- Judgment, planning, problem solving
- Speech: speaking and writing
- Body movement
- Intelligence, concentration, self awareness
The Parietal lobe controls
- Interpretation of language, words
- Sense of touch, pain, temperature (sensory strip)
- Interpretation of signals from vision, hearing, motor, sensory and memory
- Spatial and visual perception
The Occipital lobe controls
- Interpretation of vision (color, light, movement)
The Temporal lobe controls
- Understanding of language
- Memory
- Hearing
- Sequencing and organization
PTSD affects the structure of the brain. The following terms define the areas affected.
Acetylcholine: Neurotransmitter found at the neuromuscular junction, within the autonomic nervous system, and the basal forebrain. Acetylcholine neurotransmission at the neuromuscular junction is essential for skeletal muscle activation. In the brain, acetylcholine is believed to play a key role in memory.
Adrenaline/Epinephrine: A catecholamine hormone or neurotransmitter. Epinephrine is produced by the adrenal gland and by neurons within the sympathetic nervous system. Epinephrine in the bloodstream acts to increase cardiac output (heart rate, blood pressure), dilate airways, and raise blood glucose levels.
Amygdala: Almond shaped brain region (one in each temporal lobe) that plays a role in decision-making and emotional processing. The amygdala participates in pain processing, reward, anger/rage, fear and anxiety.
Autonomic nervous system: Division of the peripheral nervous system that is outside of conscious control. The autonomic nervous system drives vegetative functions such as heart rate, respiration, and pupil dilation, among others. The autonomic nervous system is further divided into the parasympathetic and sympathetic nervous systems. These systems generally work antagonistically on various organs (i.e. one causes the opposite effect of the other). Lastly, the enteric nervous system is found along the gastrointestinal tract, which produces gastric motility and aids in digestion.
Basal ganglia: A collection of brain regions connected through complex circuitry of excitatory and inhibitory pathways. The basal ganglia participates in motivation, working memory, and decision-making behaviors. Damage to certain parts of the basal ganglia causes a range of movement disorders, from hypokinetic (Parkinson’s disease; substantia nigra pars compacta) to hyperkinetic (Huntington’s disease; stratum) disorders.
Brainstem: Collection of neurons and nerve fibers at the base of the brain and at the top of the spinal cord including the midbrain, the pons, and the medulla oblongata. The brainstem maintains consciousness, regulates the sleep/wake cycle, and 10 of the 12 cranial nerves originate in the brainstem.
Catecholamine: An organic molecule that contains a catechol group and a single amine group. In neuroscience, important catecholamines are epinephrine, norepinephrine, and dopamine.
Central nervous system: The brain and spinal cord, the optic nerve, the olfactory nerves, and the retina. The central nervous system is so named as to distinguish it from the peripheral nervous system. Most regions of the central nervous system are protected by the blood brain barrier, while the peripheral nervous system is not.
Cerebellum: The second-largest brain structure after the cerebrum. It is located below the rear of the cerebrum and behind the pons/brainstem. While the cerebrum is directly responsible for movement, the cerebellum improves coordination and the precision of movements. The cerebellum is important for fine motor movements, equilibrium, and maintaining posture. The cerebellum also participates in motor learning.
Cerebral cortex: Outer portion of the cerebrum that contains the cell bodies of neurons in the brain (gray matter). The thickness of a person’s cerebral cortex roughly correlates with their intelligence quotient (IQ). As the cortex thins due to aging or neurodegenerative diseases, a person’s cognitive capacity diminishes.
Cerebrum: The largest part of the brain. It contains the cortex and subcortical structures. The cerebrum specifically does not include the cerebellum or the brainstem. The cerebrum is responsible for executive function, sensory processing, language, learning and memory formation, and voluntary movement. The cerebrum is separated into two hemispheres, which are connected by the corpus callosum.
Cognition: A term that broadly applies to the mental processes of thinking, learning, and memory. Cognition generally applies to higher mental function, rather than autonomic and automatic processes. For example, actively acquiring new knowledge is a form of cognition, but emotional reactions to events or processes that drive heart rate and breathing rate are not.
Corpus callosum: The main connection between the right and left hemispheres of the brain. The corpus callosum is comprised of nerve fibers that transmit information between cerebral hemispheres.
Cortisol: Steroid hormone produced by the adrenal glands in response to stressors such as infection, sleep deprivation, or trauma. Normal levels of cortisol are important for maintaining glucose levels and blood pressure. Chronically elevated levels of cortisol, on the other hand, can suppress the immune system, increase body weight, and interfere with cognition, among other effects.
Dopamine: A catecholamine neurotransmitter. Dopamine is produced in many neuron groups in the brain, though it is found in particularly high concentrations in the substantia nigra and in the ventral tegmental area. The role dopamine plays depends on its location. For example, dopamine in the mesolimbic pathway creates a sensation of motivation, desire, and reward. Abnormal stimulation in this region may also lead to addiction or hallucinations. On the other hand, dopamine in the nigrostriatal pathway participates in motor control.
Endorphins: Natural (endogenous) neuropeptide hormones are released in response to pain or vigorous aerobic exercise and bind to/act on opioid receptors. Like exogenous opioids, endorphins block pain signals and pain processing, which reduces the perception of pain. Endogenous endorphins can create a mild euphoria, just as exogenous opioids can.
Executive Function: Executive function includes higher-level cognitive abilities including abstract thinking, complex task planning, emotional inhibition, impulse control, and problem solving. Executive function is required to plan and initiate complex tasks, rather than more mundane or automatic behaviors.
Frontal Lobe: Front section of the cerebrum lying behind the forehead and extending back to the ears. The frontal lobe controls executive functioning, abstract thinking, decision-making, speech formation, and voluntary movements. A person’s personality mostly resides in the frontal lobe; damage to the frontal lobe can result in marked changes to personality causing anger, aggressive behavior, and social isolation.
Gamma-aminobutyric acid (GABA): The main inhibitory neurotransmitter in the central nervous system. GABA acting on GABA receptors on pre-and postsynaptic neurons hyperpolarizes neurons and makes them less likely to fire action potentials. Drugs that increase GABA activity such as benzodiazepines tend to reduce seizure potential (by reducing neuronal activity) and decrease anxiety.
Glutamate: The most abundant excitatory neurotransmitter in the central nervous system. Glutamate participates in excitatory neurotransmission in most neurons in the brain. Excessive glutamate neurotransmission may lead to excitotoxicity, which destroys neurons through excessive stimulation.
Glycine: Glycine is an inhibitory neurotransmitter found in the brain and the spinal cord. Glycine is also required along with glutamate to stimulate NMDA receptors, which is a major excitatory system in the brain. Thus, glycine has inhibitory and excitatory actions in the central nervous system.
Hippocampus: Structure within the medial temporal lobe of the brain and major component of the limbic system. The hippocampus participates in the consolidation of short-term memory into long-term memory, and participates in spatial memory. Damage to the hippocampus results in short-term memory loss, spatial memory loss, and disorientation. The hippocampus exhibits a phenomenon called long-term potentiation, which is considered a neural substrate for memory formation.
Histamine: In neuroscience, histamine primarily acts as a neuron modulator. Histamine receptor stimulation results in changes in acetylcholine, dopamine, norepinephrine, and serotonin release, and the release of certain peptides. Histamine is also a particularly potent modulator in the hypothalamus, and affects pain processing.
Hormone: A substance that is released by a gland to create a biological effect at another location in the body. For example, thyroid hormone is released by the thyroid gland in the neck to affect the metabolic activity of cells throughout the body. Hormone levels in the blood are tightly regulated under normal circumstances; abnormally high or low levels of hormones in the blood may cause a constellation of signs and symptoms.
Hypothalamus: Component of the limbic system located under the thalamus. It contains a number of nuclei with specific functions. The hypothalamus releases hormones and neuropeptides that act on the pituitary gland and/or other glands and tissues throughout the body. Once stimulated, the pituitary gland, in turn, releases hormones into the bloodstream. For example, the hypothalamus secretes thyrotropin-releasing hormone that acts on the anterior pituitary to release thyroid-stimulating hormone, which in turn stimulates the thyroid gland to release thyroid hormone.
Limbic system: A collection of brain structures including the amygdala, basal ganglia, cingulate gyrus, hippocampus, hypothalamus, and thalamus. The limbic system is responsible for integrating higher order functions (executive function, task planning) with lower order brain functions (emotional pain processing, emotional memory processing).
Locus Coeruleus: Brainstem nucleus that houses the brain’s densest concentration of norepinephrine-containing neurons. The locus coeruleus participates in arousal, attention, and memory, and it may also participate in normal and abnormal expressions of mood, alertness, and anxiety.
Neuron: A nerve cell. A nerve cell collects electrical and/or chemical input and, once conditions are met, can fire an action potential along its axon. The action potential causes the release of neurotransmitters into the synaptic cleft, which can then act on adjacent neurons. The human brain has about 100 billion neurons arranged in an astonishingly complex network.
Neuroplasticity/Plasticity: The process by which neurons, particularly in the brain, create and reorganize connections between cells to adapt to injury, environmental changes, or novel situations. Neuroplasticity explains how a person with brain injury can regain the ability to walk, as healthy regions of the brain adapt to take over the responsibilities of the injured region. Neuroplasticity also encompasses the changes that take place in the brain during learning and memory formation.
Noradrenaline/Norepinephrine: A catecholamine hormone or neurotransmitter. Norepinephrine is produced by three separate structures in the body, the adrenal gland, sympathetic nervous system ganglia, and locus coeruleus neurons in the brain. Norepinephrine acting in the systemic circulation or within the sympathetic nervous system increases heart rate and blood pressure, among other functions. In the brain, norepinephrine neurotransmission increases alertness, speed of action, and vigilance.
Occipital Lobe: Lower part of the cerebrum located at the back of the skull under the parietal lobe, behind the temporal lobe, and on top of the cerebellum. The occipital lobe is primarily involved in receiving and processing visual information. The occipital lobe compiles information from the visual pathways to create an integrated image from light that enters the eyes. The occipital lobe determines the visual attributes of vision including color, distance, and size, not only using this information to create vision but also to form visual memories.
Parietal Lobe: Top part of the cerebrum lying between the ears and the back of the skull. The parietal lobe is important for integrating sensory information influencing how we perceive information from the outside world. The parietal lobe is responsible for processing language, visual information, tactile stimulation, and visuospatial reasoning.
Peripheral nervous system: The nerves and ganglia that occur outside of the brain and spinal cord. With the exception of the optic nerves and olfactory nerves, the cranial nerves are also part of the peripheral nervous system. The peripheral nervous system is sometimes subdivided into the somatic nervous system and the autonomic nervous system. However, if it is unspecified, the peripheral nervous system indicates the somatic nervous system, which controls skeletal muscles and receives most sensory information.
Pituitary gland: Gland at the base of the brain under the hypothalamus. The pituitary gland is divided into anterior and posterior sections. The anterior pituitary gland produces growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, luteinizing hormone, and prolactin. The posterior pituitary produces oxytocin, vasopressin, and antidiuretic hormone. The hypothalamus stimulates the pituitary gland to release these hormones under certain circumstances.
Prefrontal cortex: The frontmost portion of the brain. The prefrontal cortex is responsible for complex task planning, decision-making, and appropriate social inhibition. Moreover, the prefrontal cortex is believed to generate a substantial portion of a person’s personality. The prefrontal cortex is critical for executive function and attention.
Serotonin: A monoamine neurotransmitter (aka 5-hydroxytryptamine). Serotonin in the brain is involved in mood, appetite, and sleep regulation. The primary source of serotonin in the brain is the raphe nuclei in the brainstem. Certain antidepressants (e.g. selective serotonin reuptake inhibitors) act by increasing serotonin neurotransmission.
Synapse: Anatomical area where two neurons interact with one another. At a synapse, a (presynaptic) neuron releases chemicals called neurotransmitters into the synaptic cleft, the space between two neurons. Neurotransmitters diffuse across the synaptic cleft and interact with receptors of the adjacent (postsynaptic) neuron. The neurotransmitter makes it more or less likely that the adjacent neuron will fire an action potential, depending on whether it is an excitatory or inhibitory neuron, respectively.
Temporal Lobe: Lower part of the brain that sits deep to the ears, extending from the temples back to the occipital cortex. The temporal lobe is responsible for processing auditory input and recognizing language. The temporal lobe also includes the hippocampus. Thus, the temporal lobe is important for long-term memory formation.
Thalamus: Brain structure that rests in the center of the brain below the corpus callosum that serves as a relay center of sensory information between the sensory organs and sensory cortices. All senses (except olfactory sensation) pass through the thalamus.