Communication in the brain Flashcards
What are neurons?
Neurons are the fundamental building blocks of the nervous system. They transmit electrical and chemical signals, allowing for the communication of information within the brain and between the brain and the rest of the body.
Understanding the structure and function of neurons is crucial for comprehending how thoughts, emotions, and behaviors are generated and regulated.
What are the main neurons in the body?
- Sensory Neurons
- Motor Neurons
- Interneurons
- Mirror Neurons
- Dopaminergic Neurons
- Serotonergic Neurons
- GABAergic Neurons
- Glutamatergic Neurons
- Noradrenergic Neurons
- Oxytocinergic Neurons
What are Sensory Neurons?
Sensory neurons are responsible for transmitting sensory information from the external environment (e.g., touch, temperature, pain, and sensory input from the five senses) to the central nervous system (CNS). Understanding sensory processing is essential for addressing sensory sensitivities, sensory integration issues, and related conditions like sensory processing disorder.
What are Motor Neurons?
Motor neurons are responsible for transmitting signals from the CNS to muscles and glands, controlling movement and bodily functions. Therapists working with individuals with motor impairments or movement disorders (e.g., physical therapists, occupational therapists) often focus on motor neuron function and rehabilitation.
What are Interneurons?
Interneurons are found within the CNS and facilitate communication between sensory and motor neurons. They play a crucial role in information processing, decision-making, and coordinating responses to stimuli. Understanding interneuron function is essential in addressing cognitive and emotional processes in therapy.
What are Dopaminergic Neurons?
Dopaminergic neurons release dopamine, a neurotransmitter associated with reward, pleasure, motivation, and mood regulation. Dysregulation of dopaminergic pathways is implicated in conditions like addiction and mood disorders. Therapists may focus on strategies to regulate dopamine-related behaviors and emotions.
What are Serotonergic Neurons?
Serotonergic neurons release serotonin, a neurotransmitter involved in mood regulation, anxiety, and sleep. Therapists may address serotonin levels and receptor sensitivity when working with clients experiencing depression, anxiety, or obsessive-compulsive disorders.
What are Glutamatergic Neurons?
Glutamatergic neurons release glutamate, an excitatory neurotransmitter that plays a fundamental role in learning, memory, and cognitive processes. Therapists may consider strategies to modulate glutamate levels in conditions such as schizophrenia or cognitive impairments.
What are GABAergic Neurons?
GABAergic neurons release gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter that regulates neuronal excitability. Therapists may explore GABA-related strategies for anxiety management and relaxation techniques.
What are Oxytocinergic Neurons?
Oxytocinergic neurons release oxytocin, a hormone and neurotransmitter associated with bonding, trust, and social connection. Therapists may explore oxytocin-related interventions in couples therapy, attachment-based therapy, or addressing social anxiety.
What are Noradrenergic Neurons?
Noradrenergic neurons release norepinephrine, a neurotransmitter involved in the stress response, arousal, and attention. Therapists may address noradrenergic regulation in clients dealing with anxiety, trauma, or attention-related disorders.
What are Mirror Neurons?
Mirror neurons are a type of interneuron that are thought to play a role in understanding the actions and emotions of others. They are relevant in therapy for empathy development, social skills training, and addressing conditions involving social cognition deficits, such as autism spectrum disorders.
What is the approximate number of neurons in the average human brain?
There are approximately 100 billion neurons in the average human brain.
What percentage of all cells in the brain do neurons account for?
Neurons account for only 10 percent of all cells in the brain.
What are the remaining 90 percent of cells in the brain called, and what is their primary function?
The remaining 90 percent of cells in the brain are known as glial cells, or support cells. Their primary function is to provide support and various essential functions to neurons.
What are the main Glial cells in the body?
Astrocytes: Astrocytes are involved in various functions, including maintaining the blood-brain barrier, regulating ion balance, and providing metabolic support to neurons.
Oligodendrocytes: Oligodendrocytes myelinate axons, which is essential for the rapid conduction of nerve impulses.
Microglia: Microglia are the brain’s resident immune cells and play a role in immune responses and maintaining brain health.
Ependymal Cells: Ependymal cells line the ventricles and contribute to the production and circulation of cerebrospinal fluid.
What is the main type of glial cell discussed in the context of brain function?
Astrocytes are the most abundant type of glial cell discussed in the context of brain function.
What are some key roles and functions of astrocytes in the brain?
Serving as a physical scaffolding framework for neurons.
Maintaining the blood-brain barrier, which helps protect the brain from infections.
Connecting to blood vessels with foot processes, which maintain structural integrity.
Maintaining an optimal microenvironment around neurons.
Buffering potassium after depolarization.
Metabolizing and recycling neurotransmitters, especially glutamate.
Assisting with repairs after brain injuries by forming “glial scars.”
Why is the maintenance of an optimal microenvironment around neurons important?
Maintaining an optimal microenvironment around neurons is important because it helps regulate ion concentrations, buffers against changes in ion levels, and ensures the proper functioning of neurons.
What is the significance of astrocytes’ role in metabolizing and recycling neurotransmitters?
Astrocytes play a critical role in metabolizing and recycling neurotransmitters, especially glutamate, to prevent excess levels of neurotransmitters, which can be toxic to neurons
Define Dopamine Neurotransmitter?
Dopamine is a chemical neurotransmitter produced and released by dopaminergic neurons.
It is one of the many neurotransmitters used by the nervous system to transmit signals between neurons.
Dopamine plays a crucial role in various brain functions, including regulating mood, motivation, reward, and movement.
It functions as a signaling molecule that binds to specific receptors on the surface of target neurons to transmit signals.
Dysregulation of dopamine neurotransmission is implicated in conditions like depression, addiction, and certain neurological disorders.
What is the difference between dopaminergic neurons and the dopamine neurotransmitter?
dopaminergic neurons are specialized neurons that produce and release dopamine, while dopamine is the neurotransmitter itself that carries out signaling functions in the brain. Dopaminergic neurons are responsible for synthesizing and releasing dopamine, which then acts on target neurons by binding to dopamine receptors to influence various physiological and psychological processes.
Define Serotonin Neurotransmitter?
Serotonin is a chemical neurotransmitter produced and released by serotonin neurons.
It is one of the key neurotransmitters used by the nervous system to transmit signals between neurons.
Serotonin plays a vital role in regulating mood, emotional states, sleep, appetite, and various other physiological and behavioral processes.
As a neurotransmitter, serotonin functions by binding to specific receptors on the surface of target neurons, initiating signaling pathways and influencing various physiological responses.
What is the difference between serotonin neurons and the serotonin neurotransmitter?
Serotonin neurons are specialized neurons that produce and release serotonin, while serotonin is the neurotransmitter itself that carries out signaling functions in the brain. Serotonin neurons synthesize and release serotonin, which then acts on target neurons by binding to serotonin receptors to regulate a wide range of physiological and psychological processes. Dysregulation of serotonin neurotransmission is associated with mood disorders, anxiety, and other neurological and psychiatric conditions.
Define Norepinephrine Neurotransmitter?
Norepinephrine, also known as noradrenaline, is a chemical neurotransmitter produced and released by norepinephrine neurons.
It serves as a neurotransmitter to transmit signals between neurons and other target cells, including muscle cells and gland cells.
Norepinephrine is involved in various physiological processes, including increasing heart rate, constricting blood vessels, and mobilizing energy resources in response to stress or danger.
As a neurotransmitter, norepinephrine functions by binding to specific receptors (adrenergic receptors) on the surface of target cells, leading to various physiological responses based on the receptor subtype and location.
What is the difference between norepinephrine (NE) neurons and the norepinephrine neurotransmitter?
Norepinephrine neurons are specialized neurons that produce and release norepinephrine, while norepinephrine is the neurotransmitter itself that carries out signaling functions in the nervous system and other tissues. Norepinephrine neurotransmission plays a vital role in regulating both the central and peripheral nervous systems’ responses to stress, alertness, and other physiological processes. Dysregulation of norepinephrine can have significant implications for mood disorders and other health conditions.
Define GABA Neurotransmitter
GABA Neurotransmitter:
GABA is a chemical neurotransmitter produced and released by GABAergic neurons.
It is the primary inhibitory neurotransmitter in the central nervous system and is essential for reducing neural activity and dampening the firing of neurons.
GABA plays a crucial role in promoting relaxation, reducing anxiety, and preventing overstimulation of neurons.
As a neurotransmitter, GABA functions by binding to specific receptors (GABA receptors, such as GABA-A and GABA-B receptors) on the surface of target neurons, leading to hyperpolarization and decreased neuronal excitability.
What is the difference between GABA (Gamma-Aminobutyric Acid) neurons and the GABA neurotransmitter?
GABA neurons are specialized neurons that produce and release GABA, while GABA is the neurotransmitter itself that carries out inhibitory signaling functions in the brain. GABAergic neurons synthesize and release GABA, which then acts on target neurons by binding to GABA receptors to promote neuronal inhibition and maintain a balance between excitatory and inhibitory signaling in the brain. Dysregulation of GABA neurotransmission can be associated with various neurological and psychiatric disorders.
Define Glutamate Neurotransmitter
Glutamate is a chemical neurotransmitter produced and released by glutamate neurons.
It is the primary excitatory neurotransmitter in the central nervous system and is essential for promoting neural activity and communication between neurons.
Glutamate plays a crucial role in various cognitive functions, learning, memory, and sensory processing.
As a neurotransmitter, glutamate functions by binding to specific receptors (such as NMDA, AMPA, and kainate receptors) on the surface of target neurons, leading to depolarization and the initiation of action potentials.
What can excess levels of GABA (Inhibitory neurotransmitter) cause?
Sedation and Drowsiness: Excessive GABA activity can result in sedation, drowsiness, and a lack of alertness.
Muscle Weakness: Elevated GABA levels may lead to muscle weakness and poor coordination.
What is the difference between glutamate neurons and the glutamate neurotransmitter?
Glutamate neurons are specialized neurons that produce and release glutamate, while glutamate is the neurotransmitter itself that carries out excitatory signaling functions in the brain. Glutamate neurons synthesize and release glutamate, which then acts on target neurons by binding to glutamate receptors to promote neuronal excitation and communication. Dysregulation of glutamate neurotransmission can be associated with various neurological and psychiatric disorders.
What can excess levels of Glutamate (Excitatory neurotransmitter) cause?
Neurotoxicity: Excessive glutamate can overstimulate neurons, leading to neurotoxicity and cell damage, which may contribute to neurodegenerative conditions like Alzheimer’s disease.
Anxiety and Agitation: Elevated glutamate levels can result in heightened anxiety, restlessness, and agitation due to increased neuronal activity.
What can excess levels of Serotonin (Inhibitory neurotransmitter) cause?
Serotonin Syndrome: Abnormally high serotonin levels, often caused by the use of certain medications, can lead to serotonin syndrome. Symptoms include confusion, agitation, high body temperature, rapid heart rate, and even seizures.
GI Disturbances: Elevated serotonin can cause gastrointestinal symptoms such as nausea, diarrhea, and abdominal pain.
What can excess levels of Norepinephrine (Excitatory neurotransmitter) cause?
Anxiety and Stress: High levels of norepinephrine are associated with increased anxiety, stress, and heightened fight-or-flight responses.
Hypertension: Elevated norepinephrine can lead to elevated blood pressure and increased risk of cardiovascular issues.
What can excess levels of Dopamine (Excitatory neurotransmitter) cause?
Psychosis: Excess dopamine is associated with psychotic disorders such as schizophrenia. It can lead to hallucinations, delusions, and disorganized thinking.
Mania: Elevated dopamine levels can contribute to manic episodes in individuals with bipolar disorder, characterized by high energy, impulsivity, and elevated mood.
Why is excess glutamate in the brain considered toxic, and what neurotransmitter is most commonly involved in ionotropic transmission?
Excess glutamate in the brain is considered toxic because it can lead to neuronal damage and cell death. Glutamate is the most common neurotransmitter involved in ionotropic transmission in the brain.
What is the primary role of oligodendrocytes in the brain?
Oligodendrocytes are a type of cell in the brain responsible for myelinating axons. They wrap a fatty layer around axons to insulate them and speed up the conduction of electrical impulses.
How does myelination by oligodendrocytes prevent cross-conduction between neurons?
Myelination by oligodendrocytes insulates axons, preventing cross-conduction between neurons. This means neurons only affect each other when intended.
When does the process of myelination begin, and how does it progress throughout life?
Myelination begins in utero, wrapping fatty layers around axons in concentric lamellae. It continues throughout life but is largely finished after the first year. Complete myelination, especially in the prefrontal cortex, may not occur until around 20 years old.
What are the psychological challenges associated with the phenomenon of complete myelination, particularly in the prefrontal cortex, not occurring until around 20 years old?
Impulse Control: The prefrontal cortex plays a crucial role in impulse control, decision-making, and planning. Incomplete myelination in this region can lead to challenges in regulating impulsive behaviors. Adolescents and young adults may struggle to think through the consequences of their actions and make sound judgments.
Emotional Regulation: The prefrontal cortex also contributes to emotional regulation. Without full myelination, individuals may find it difficult to manage their emotions effectively. This can lead to heightened emotional reactivity, mood swings, and difficulty coping with stressors.
Risk-Taking Behavior: Incomplete myelination in the prefrontal cortex is associated with a greater propensity for risk-taking behavior. Young individuals may be more inclined to engage in risky activities, such as substance abuse or reckless driving, without fully considering the potential negative outcomes.
Delayed Decision-Making: Decision-making processes can be slower and less efficient in individuals with underdeveloped prefrontal cortices. They may struggle with making important life choices, such as career decisions or relationship commitments.
Peer Influence: Adolescents and young adults are particularly susceptible to peer influence. The still-developing prefrontal cortex may make it challenging for them to resist peer pressure and make independent decisions based on long-term goals and values.
Cognitive Control: Cognitive control functions, such as working memory and attention, rely on the prefrontal cortex. Incomplete myelination can result in difficulties in maintaining focus, organizing thoughts, and managing complex tasks.
Academic and Occupational Challenges: The prefrontal cortex’s role in executive functions can impact academic performance and occupational success. Young individuals may struggle with tasks that require planning, organization, and time management.
Vulnerability to Mental Health Issues: The prefrontal cortex is also involved in the regulation of mood and the development of mental health disorders. Incomplete myelination may contribute to a higher susceptibility to conditions such as depression, anxiety, and impulse control disorders.
Risk of Substance Abuse: The increased vulnerability to substance abuse during adolescence and young adulthood may partly be attributed to incomplete myelination. Impulsivity and poor decision-making can lead to experimentation with drugs and alcohol.
Legal Implications: Incomplete myelination can have legal implications for young individuals. They may be more likely to engage in illegal activities and face legal consequences due to their impaired judgment.
Why is the brain vulnerable to damage during the period when myelination is not yet complete?
The brain is vulnerable to insults during the period before myelination is complete because myelination helps protect and optimize neural function. Damage during this time can have lasting effects.
What is the role of microglia in the central nervous system (CNS)?
Microglia are CNS macrophages responsible for clearing waste material, including apoptosis (programmed cell death) in utero. In adults, they are usually highly immunosuppressed and only activate in response to specific immune conditions, such as infection.
Where are microglia found within the brain and its surrounding structures?
Microglia are found amongst neurons, in blood vessels in the brain, and in the meninges that surround the brain.
What is the primary function of ependymal cells in the brain?
Ependymal cells line the ventricles in the brain and are responsible for secreting and absorbing cerebrospinal fluid.
How can a therapist or medical professional utilize the knowledge of myelination by oligodendrocytes to support individuals with neurological disorders or cognitive deficits?
Customized Rehabilitation Plans: Understanding the role of oligodendrocytes in myelination allows therapists to create customized rehabilitation plans. These plans can focus on exercises and interventions that promote neural plasticity and remyelination in areas of the brain affected by injury or disease.
Timing of Interventions: For example, early intervention during childhood or adolescence may take advantage of ongoing myelination processes.
Cognitive Training: Therapists can design cognitive training programs that target specific brain regions and functions, taking into account the role of myelination in neural transmission speed.
Monitoring Progress: Understanding myelination can aid in monitoring a patient’s progress during therapy.
Medication Management: In cases where demyelination occurs due to conditions like multiple sclerosis, therapists can work in conjunction with medical professionals to manage medications and therapies that slow or repair myelin damage.
Education and Counseling: Therapists can educate patients and their families about the importance of myelination and the potential impact of therapies. This knowledge can empower individuals to actively participate in their treatment plans.
What are several common factors that can contribute to a decrease in myelin growth and a decline in axonal health in the nervous system, with significant implications for neurological and mental health?
Aging: Myelin maintenance and repair become less efficient with age, leading to gradual demyelination and decreased axonal health. This natural process can result in cognitive decline and increased susceptibility to neurological disorders.
Neurodegenerative Diseases: Conditions such as multiple sclerosis (MS), Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS) are characterized by demyelination and axonal damage. In these diseases, the immune system may attack myelin, and neuronal proteins may misfold, contributing to the breakdown of axonal health.
Traumatic Brain Injury (TBI): Physical trauma to the brain can disrupt myelin sheaths and damage axons. TBI can lead to long-term cognitive and motor deficits, depending on the severity and location of the injury.
Autoimmune Disorders: Some autoimmune diseases, such as Guillain-Barré syndrome, can target myelin and cause demyelination. This leads to impaired nerve signal transmission and affects motor and sensory functions.
Metabolic Disorders: Certain metabolic disorders, like adrenoleukodystrophy (ALD) and Krabbe disease, interfere with myelin synthesis and maintenance. These rare genetic conditions can result in severe neurological symptoms.
Toxic Exposures: Exposure to environmental toxins or chemicals can damage myelin and axons. For example, exposure to heavy metals like lead can lead to neurotoxicity and demyelination.
Nutritional Deficiencies: Inadequate intake of essential nutrients, particularly those required for myelin synthesis (e.g., vitamin B12 and folate), can impact myelin growth and axonal health. Malnutrition or certain gastrointestinal conditions may lead to nutrient deficiencies.
Inflammatory Processes: Chronic inflammation in the central nervous system can disrupt myelin and axonal integrity. Inflammation may result from infections, autoimmune reactions, or other immune-related conditions.
Genetic Factors: Some individuals may have genetic mutations or variations that predispose them to myelin disorders or axonal dysfunction. These genetic factors can affect the development and maintenance of myelin and axons.
Vascular Issues: Reduced blood flow to the brain, as seen in conditions like cerebral small vessel disease, can compromise myelin health. This can lead to white matter lesions and cognitive impairment.
Chronic Stress: Prolonged stress can have detrimental effects on neural health, potentially contributing to myelin damage and axonal dysfunction. Stress-related hormones like cortisol can impact the brain’s structure and function.
Neuroinflammation: Persistent neuroinflammation, often associated with chronic conditions like depression or neuroinflammatory disorders, can disrupt myelin growth and axonal health.