psych 261 lecture 4
47 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary role of snare proteins in neurotransmitter release?

  • To move vesicles from the reserve pool to the recycling pool.
  • To form the membrane of the synaptic vesicles.
  • To facilitate the docking and priming of vesicles at the active zone. (correct)
  • To transport neurotransmitters into the vesicles.

    • According to the information provided, which of the following pools contains the largest proportion of synaptic vesicles?

  • The reserve pool (correct)
  • The readily releasable pool
  • The recycling pool
  • The active zone pool

    • What process occurs immediately after a vesicle translocates to the active zone?

  • Microtubules facilitate vesicle movement away from the active zone.
  • The vesicles are broken down and removed from the terminal.
  • Snare proteins attach to the vesicle and the axon membrane. (correct)
  • Neurotransmitters enter the vesicle.

    • What stage of synaptic vesicle movement is responsible for moving vesicles towards the active zone?

    <p>Translocation (B)</p> Signup and view all the answers

    Approximately what percentage of synaptic vesicles are part of the recycling pool?

    <p>5-20% (D)</p> Signup and view all the answers

    Which of the following is a precursor to serotonin?

    <p>Tryptophan (C)</p> Signup and view all the answers

    Which neurotransmitter is synthesized from choline and acetyl coenzyme A?

    <p>Acetylcholine (A)</p> Signup and view all the answers

    Which of the following is classified as a catecholamine?

    <p>Norepinephrine (A)</p> Signup and view all the answers

    Where are neuropeptides synthesized?

    <p>Soma (B)</p> Signup and view all the answers

    Which of these is an indolamine neurotransmitter?

    <p>Melatonin (C)</p> Signup and view all the answers

    Which of the following is an amino acid neurotransmitter listed?

    <p>GABA (D)</p> Signup and view all the answers

    The reuptake of neurotransmitters is associated with which of the following?

    <p>Presynaptic axon terminal (D)</p> Signup and view all the answers

    Which of the following is considered a peptide neurotransmitter?

    <p>Insulin (D)</p> Signup and view all the answers

    What is the immediate effect of demyelination on the action potential?

    <p>The action potential is disrupted. (A)</p> Signup and view all the answers

    Which cellular structure is directly associated with the formation of axonal ovoids?

    <p>Demyelinated axon. (D)</p> Signup and view all the answers

    Which cells are primarily involved with the remyelination of axons during recovery?

    <p>NG2 cells or oligodendrocytes (B)</p> Signup and view all the answers

    What is the primary structural change that allows for continued action potential propagation after demyelination, in outcome 2?

    <p>Insertion of new ion channels into the membrane. (C)</p> Signup and view all the answers

    Which condition is directly associated with axonal demyelination?

    <p>Multiple Sclerosis. (A)</p> Signup and view all the answers

    What is the function of a healthy neuron taking over the functions of a damaged one?

    <p>Maintaining system functionality despite neuron damage. (D)</p> Signup and view all the answers

    What structural feature of a neuron is directly affected by a lack of myelin?

    <p>Axon. (C)</p> Signup and view all the answers

    What is not a direct outcome of the demyelination of an axon?

    <p>Immediate cell lysis. (B)</p> Signup and view all the answers

    Which of the following processes is most directly associated with the movement of substances from the gut into the bloodstream?

    <p>Translocation (D)</p> Signup and view all the answers

    An imbalance in gut bacteria, characterized by a reduction in beneficial microbes, is referred to as what?

    <p>Dysbiosis (B)</p> Signup and view all the answers

    According to the figure, what is the primary function of the intestinal epithelium?

    <p>To form a barrier between the gut and the circulatory system. (D)</p> Signup and view all the answers

    Which type of cell is responsible for producing the myelin sheath that protects neurons in the brain?

    <p>Oligodendrocyte (A)</p> Signup and view all the answers

    What is the role of the blood-brain barrier as shown in the diagram?

    <p>To prevent inflammatory substances from easily reaching brain tissues. (A)</p> Signup and view all the answers

    Where do lymphocytes in the diagram migrate to, upon crossing the blood vessel epithelium?

    <p>Brain Tissue (A)</p> Signup and view all the answers

    According to the diagram, what process can be associated with the breakdown of myelin segments?

    <p>Translocation of pro-inflammatory substances to the brain. (D)</p> Signup and view all the answers

    Which of these is not shown as playing a role in the transfer of substances from the gut to the brain?

    <p>Oligodendrocytes (B)</p> Signup and view all the answers

    What characterizes the brain lesions associated with multiple sclerosis?

    <p>A loss of myelin. (D)</p> Signup and view all the answers

    Which of the following best describes the progression of multiple sclerosis symptoms?

    <p>Symptoms are intermittent initially and then become progressively worse. (A)</p> Signup and view all the answers

    What role do lymphocytes play in the progression of multiple sclerosis?

    <p>They invade the brain through a compromised blood-brain barrier. (D)</p> Signup and view all the answers

    Which group displays a higher prevalence of multiple sclerosis according to the content?

    <p>People of European ancestry. (C)</p> Signup and view all the answers

    What is the significance of a ‘leaky’ blood-brain barrier in the context of multiple sclerosis?

    <p>It allows immune cells to access the brain. (C)</p> Signup and view all the answers

    Which of the following symptoms is not directly mentioned as a symptom of multiple sclerosis in the content?

    <p>Respiratory problems. (D)</p> Signup and view all the answers

    What does the presence of few Na+ channels imply in the context of the provided information?

    <p>A decrease in the ability for effective nerve signal transition. (C)</p> Signup and view all the answers

    What does the research of Barrie et al. (2024) suggest about the genetic risk for multiple sclerosis?

    <p>It is elevated in steppe pastoralist populations. (B)</p> Signup and view all the answers

    According to the diagram, what is the first event that occurs in the development of multiple sclerosis?

    <p>The blood-brain barrier becomes more porous. (C)</p> Signup and view all the answers

    Which of the following cell types is NOT directly involved in the inflammatory process within the brain that is associated with multiple sclerosis according to the diagram?

    <p>Oligodendrocytes (A)</p> Signup and view all the answers

    What is the role of inflammatory mediators in the progression of multiple sclerosis according to the diagram?

    <p>They cause the breakdown of myelin segments. (A)</p> Signup and view all the answers

    What is the primary result of damage to myelin segments, according to the diagram?

    <p>It exposes a segment of axon. (B)</p> Signup and view all the answers

    According to the diagram, what is the final consequence of the progression of multiple sclerosis?

    <p>Withering of the axon. (B)</p> Signup and view all the answers

    What is the function of astrocytes in relation to the blood brain barrier in the context of the diagram?

    <p>They are essential for maintaining a healthy blood-brain barrier. (A)</p> Signup and view all the answers

    What does the diagram suggest about the direct interaction between lymphocytes and oligodendrocytes in the context of MS progression?

    <p>Lymphocytes release inflammatory substance, impacting myelin. (B)</p> Signup and view all the answers

    According to the diagram, what is the state of myelin segments on a healthy neuron?

    <p>Myelin segments are fully intact. (A)</p> Signup and view all the answers

    How does the increased porosity of the blood-brain barrier as shown in the diagram, contribute to multiple sclerosis?

    <p>It allows immune cells like lymphocytes to enter the brain. (B)</p> Signup and view all the answers

    Based on the diagram, in what sequence do microglia and lymphocytes cause damage during the progression of multiple sclerosis?

    <p>Lymphocytes act first, followed by microglia. (A)</p> Signup and view all the answers

    Flashcards

    Passive Conduction

    The slow, continuous movement of an action potential along an unmyelinated axon.

    Saltatory Conduction

    The rapid, jumping movement of an action potential along a myelinated axon, where the signal jumps from one node of Ranvier to the next.

    Multiple Sclerosis (MS)

    An autoimmune disorder that attacks the myelin sheath surrounding nerve fibers in the central nervous system, leading to disruption of nerve impulse transmission. This can result in a range of symptoms, including muscle weakness, sensory problems, and cognitive deficits.

    Stage 1 of MS

    The initial stage of multiple sclerosis, characterized by intermittent symptoms that often resolve on their own.

    Signup and view all the flashcards

    Stage 2 of MS

    The second stage of multiple sclerosis, characterized by a gradual worsening of symptoms over time. This stage is marked by a progressive deterioration of neurological function.

    Signup and view all the flashcards

    Blood-Brain Barrier

    The protective barrier that surrounds the brain and spinal cord, preventing harmful substances from entering the central nervous system.

    Signup and view all the flashcards

    Brain Lesion in MS

    A region of the brain that has been damaged due to inflammation or loss of myelin in MS. These lesions can impair nerve signal transmission.

    Signup and view all the flashcards

    European ancestry and MS

    The presence of a higher prevalence of multiple sclerosis among individuals of European ancestry compared to other populations.

    Signup and view all the flashcards

    Astrocyte

    A type of glial cell that helps maintain the blood-brain barrier and provides structural support for neurons in the central nervous system.

    Signup and view all the flashcards

    Microglia

    A type of glial cell that acts as the brain's immune cells, clearing debris and protecting against pathogens.

    Signup and view all the flashcards

    Brain Inflammation

    The process of inflammation in the brain, characterized by the activation of immune cells and the release of inflammatory mediators, often triggered by an infection or injury.

    Signup and view all the flashcards

    Blood-brain barrier permeability

    Changes in the blood-brain barrier, making it more permeable to substances that normally cannot pass through it, often caused by inflammation.

    Signup and view all the flashcards

    Lymphocytes

    Specialized cells involved in the immune response, including the production of antibodies and the destruction of infected cells.

    Signup and view all the flashcards

    Inflammatory mediators

    Chemical messengers released by immune cells during inflammation, involved in signaling and modulating immune responses.

    Signup and view all the flashcards

    Myelin

    The insulating sheath around nerve fibers, made of a fatty substance called myelin, that helps to speed up the transmission of nerve impulses.

    Signup and view all the flashcards

    Demyelination

    Damage to the myelin sheath around nerve fibers, leading to disruptions in nerve signal transmission.

    Signup and view all the flashcards

    Axon Withering

    The breakdown of the axon of a neuron downstream from demyelination, leading to impaired or lost function of the affected neuron.

    Signup and view all the flashcards

    Microbial Translocation

    The process by which bacteria or other microorganisms move from the gut to the bloodstream.

    Signup and view all the flashcards

    Oligodendrocyte

    A type of glial cell that produces myelin, a fatty substance that insulates nerve fibers.

    Signup and view all the flashcards

    Gut Dysbiosis

    An imbalance in the bacteria that normally live in the gut.

    Signup and view all the flashcards

    Translocation of neurotransmitters

    The process where neurotransmitters move from their storage location within the axon terminal to the active zone, the site of release into the synaptic cleft.

    Signup and view all the flashcards

    Active zone

    A specialized area within the axon terminal where neurotransmitters are released into the synaptic cleft.

    Signup and view all the flashcards

    Snare proteins

    Proteins that connect synaptic vesicles containing neurotransmitters to the axon membrane, facilitating their fusion and release.

    Signup and view all the flashcards

    Readily releasable pool

    A group of vesicles that are ready to release neurotransmitters immediately, representing the most readily available pool.

    Signup and view all the flashcards

    Reserve pool

    A large pool of vesicles containing neurotransmitters that are stored within the axon terminal and are less readily available for immediate release.

    Signup and view all the flashcards

    Ion Channels

    Specialized proteins embedded in the cell membrane of neurons that control the flow of ions into and out of the cell, crucial for nerve impulse transmission.

    Signup and view all the flashcards

    Axonal Ovoid

    A spherical structure formed at the end of a demyelinated axon, often associated with axonal degeneration in diseases like multiple sclerosis.

    Signup and view all the flashcards

    NG2 Cells

    A type of cell that can potentially contribute to the formation of new oligodendrocytes, which play a role in remyelination.

    Signup and view all the flashcards

    Intestinal Wall Weakening

    The weakening of the intestinal wall, often caused by factors like stress, pathogens, or dysbiosis, and can contribute to conditions like leaky gut syndrome.

    Signup and view all the flashcards

    Synapse

    Specialized junctions where nerve cells communicate with each other, allowing the transfer of information via chemical signals.

    Signup and view all the flashcards

    Adhesion Molecules

    Molecules that help neurons adhere to each other, providing structural support and stability within the synapse.

    Signup and view all the flashcards

    Neurotransmitters

    Chemical messengers that are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron, transmitting signals across the synaptic cleft.

    Signup and view all the flashcards

    Presynaptic Axon Terminal

    The terminal end of an axon where neurotransmitters are stored in vesicles and released into the synaptic cleft.

    Signup and view all the flashcards

    Postsynaptic Dendritic Spine

    A small protrusion on a dendrite that receives signals from other neurons at the synapse.

    Signup and view all the flashcards

    Amine Neurotransmitters

    A type of neurotransmitter that is synthesized from amino acids, including dopamine, norepinephrine, epinephrine, serotonin, and melatonin.

    Signup and view all the flashcards

    Other Small Molecules Neurotransmitters

    A group of neurotransmitters that are small molecules that are released from neurons and act on target cells to produce a response.

    Signup and view all the flashcards

    Peptide Neurotransmitters

    Neurotransmitters that are made up of chains of amino acids, including enkaphalins, substance P, and insulin.

    Signup and view all the flashcards

    Study Notes

    Action Potential

    • Action potentials are rapid changes in membrane voltage, occurring in a small region of the axon
    • The absolute refractory period is the time the axon cannot fire another action potential
    • The relative refractory period is the time where additional stimulus is needed to fire another action potential.

    Varieties of Action Potentials

    • CA1 pyramidal neurons have a width of 810 µs
    • Dopamine neurons have a width of 4 ms
    • Action potentials are described by the 'all-or-none law'
      • The magnitude of the action potential remains the same despite varying levels of stimulation

    Propagation of the Action Potential

    • The action potential is regenerated at adjacent regions of the axon, resulting in its movement down the axon
    • Action potential is self-regenerating
    • Absolute refractory period prevents backwards movement

    Passive and Saltatory Conduction

    • Myelinated axons use saltatory conduction, hopping between nodes of Ranvier, for rapid signal transmission
    • Passive conduction is slower, as the action potential spreads along the axon

    Multiple Sclerosis: An Autoimmune Disorder

    • Multiple sclerosis (MS) is neurological disease marked by intermittent and progressive symptoms
    • Symptoms associated with MS include: Muscle Weakness, Sensory Problems, Cognitive Deficits, Brain lesions, Loss of myelin, damage to neurons

    Multiple Sclerosis: Genetic Factors

    • Higher prevalence of MS in individuals of European ancestry
    • Multiple genetic variants are associated with MS development

    Overview of Action Potential and Transmission

    • The action potential travels down the axon
    • The axon terminal releases neurotransmitters
    • The neurotransmitters bind to receptors on the postsynaptic cell
    • Graded potentials (EPSPs and IPSPs) occur in the postsynaptic neuron
    • These graded potentials can lead to temporal and spatial summation

    Synapse and Neurotransmitters

    • Neurotransmitters are released from the presynaptic axon terminal into the synaptic cleft
    • Neurotransmitter receptors on the postsynaptic dendrite bind to the neurotransmitters
    • Neurotransmitters bind to receptors on the dendrite
    • Synaptic transmission involves neurotransmitter release, receptor binding, and signal transduction

    Neurotransmitter Release

    • Vesicles containing neurotransmitters are translocated to the active zone
    • Neurotransmitters are released via docking and priming of the snare proteins
    • The readily releasable pool of vesicles is situated closest to the active zone for quick release

    Vesicle Pools

    • Vesicles are grouped into reserve, recycling, and readily releasable pools
    • The readily releasable pool is near the active zone and prepared for immediate release

    Action Potential Mechanisms

    • Voltage-dependent potassium and sodium channels control action potential propagation
    • Voltage-dependent calcium channels initiate neurotransmitter release
    • SNARE proteins mediate vesicle fusion with the membrane

    Synaptic Transmission: Postsynaptic Potentials

    • Excitatory postsynaptic potentials (EPSPs) depolarize the postsynaptic neuron
    • Inhibitory postsynaptic potentials (IPSPs) hyperpolarize the postsynaptic neuron
    • Temporal and spatial summation can integrate multiple EPSPs and IPSPs

    Neurotransmitter Receptors

    • Ionotropic receptors: Rapid, short-lived responses (e.g., acetylcholine receptors, GABA receptors) - directly bind to channels
    • Metabotropic receptors: slower, longer-lasting responses (e.g., muscarinic acetylcholine receptors, GABAB receptors) - utilize G-proteins and second messengers

    Neurotransmitter Effects

    • Neurotransmitter effects on the postsynaptic cell depend on the receptor and channel involved
    • Receptors mediate the cellular response to the neurotransmitter
    • Neurotransmitters can evoke fast or slow responses

    Neurotransmitter Removal

    • Neurotransmitters are removed through reuptake by the presynaptic neuron, diffusion away, or enzymatic degradation

    Retrograde Transmission

    • Neurotransmitters are released from the postsynaptic neuron, influencing the presynaptic neuron's activity

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Psych 261 Lecture 4 Jan 15 2025 PDF

    Description

    This quiz covers the essentials of action potentials in neurons, including their characteristics, refractory periods, and propagation methods. Explore how factors like myelination affect signal transmission within the nervous system.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser