Neuroscience: Synaptic Transmission
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Questions and Answers

What is a common effect of phencyclidine and related drugs on perception?

  • Enhanced emotional responses
  • Improved cognitive function
  • Increased pain sensitivity
  • Distorted perceptions of sounds (correct)

    • How do cocaine and amphetamine primarily affect neurotransmitter action?

  • They stimulate the production of neurotransmitters
  • They block the synthesis of neurotransmitters
  • They inhibit the normal recycling of neurotransmitters (correct)
  • They enhance the reuptake of neurotransmitters

    • Which receptor type do narcotic analgesics act upon to modulate physiological functions?

  • Mu (μ) receptors (correct)
  • Delta (δ) receptors
  • Sigma (σ) receptors
  • Kappa (κ) receptors

    • What potential adverse effect is associated with the use of drugs like phencyclidine?

    <p>Higher risk of seizures</p> Signup and view all the answers

    What defines the action of sigma ligands in pharmacology?

    <p>They bind with high affinity and modulate various physiological effects.</p> Signup and view all the answers

    What is the initial step in synaptic transmission where the transmitter is created?

    <p>Transmitter Synthesis</p> Signup and view all the answers

    During synaptic transmission, how is the neurotransmitter removed from the synaptic gap?

    <p>Reuptake into the presynaptic neuron</p> Signup and view all the answers

    What occurs after the transmitter binds to receptors on the postsynaptic cell?

    <p>Generation of an action potential</p> Signup and view all the answers

    What can happen to a neurotransmitter after it has triggered a synaptic response?

    <p>It can be broken down by enzymes</p> Signup and view all the answers

    What is the function of neuropharmacological drugs in synaptic transmission?

    <p>Altering receptor activity on target cells</p> Signup and view all the answers

    What occurs to the transmitter during the transmitter storage step?

    <p>It is packaged into vesicles</p> Signup and view all the answers

    What is the role of transmitter molecules in the synaptic gap?

    <p>They diffuse and bind to receptors</p> Signup and view all the answers

    Which step follows the arrival of an action potential in synaptic transmission?

    <p>Transmitter Release</p> Signup and view all the answers

    What is the primary mechanism of action for opioid agonists?

    <p>Bind to opioid receptor sites</p> Signup and view all the answers

    Which of the following is a common side effect associated with opioid agonists?

    <p>Constipation</p> Signup and view all the answers

    What role does GABA play in anxiolytics?

    <p>Increases GABA levels</p> Signup and view all the answers

    Which part of the brain is primarily involved in emotional and behavioral responses?

    <p>Limbic system</p> Signup and view all the answers

    What is a defining characteristic of opioid receptor sites?

    <p>They exhibit G protein-coupled receptor activity</p> Signup and view all the answers

    What effect do opioid agonists typically produce besides pain relief?

    <p>Euphoric effect</p> Signup and view all the answers

    What distinguishes opioid agonist-antagonists from full opioid agonists?

    <p>They bind to the opioid receptor sites and exhibit partial antagonist actions</p> Signup and view all the answers

    Which neurotransmitters do opioid receptors have interactions with?

    <p>Dopamine and GABA</p> Signup and view all the answers

    What is a common side effect associated with sedation medications?

    <p>Respiratory depression</p> Signup and view all the answers

    Which of the following medications is classified as a Tricyclic antidepressant?

    <p>Amitriptyline</p> Signup and view all the answers

    What is the primary mechanism of non-opioid analgesics in reducing pain?

    <p>Inhibition of prostaglandin synthesis</p> Signup and view all the answers

    The primary action of monoamine oxidase inhibitors (MAO) involves which process?

    <p>Preventing neurotransmitter metabolism</p> Signup and view all the answers

    Which of the following is NOT a typical symptom of alcohol withdrawal?

    <p>Euphoria</p> Signup and view all the answers

    Which of the following is NOT a side effect commonly associated with non-opioid analgesics?

    <p>Constipation</p> Signup and view all the answers

    Which side effect is commonly associated with antidepressant medications?

    <p>Blurred vision</p> Signup and view all the answers

    What effect do prostaglandins have on the body's functions?

    <p>They influence inflammation, pain, and uterine contractions.</p> Signup and view all the answers

    Antipsychotic medications primarily act on which type of receptors?

    <p>Post synaptic dopamine receptors</p> Signup and view all the answers

    What is the function of the hypothalamic thermoregulatory center?

    <p>To act as the body's thermostat and maintain temperature regulation</p> Signup and view all the answers

    What is the primary indication for the use of antidepressants?

    <p>Depression</p> Signup and view all the answers

    Which class of medicines is specifically indicated for both pain and fever?

    <p>Salicylates</p> Signup and view all the answers

    Which of the following medications is used primarily for its sedative properties?

    <p>Phenobarbital</p> Signup and view all the answers

    Narcotic antagonists are primarily used for what purpose?

    <p>To reverse toxicity associated with opioid overdose</p> Signup and view all the answers

    How do non-steroidal anti-inflammatory drugs (NSAIDs) exert their anti-pyretic effect?

    <p>Through peripheral vasodilation or acting on the thermoregulatory center</p> Signup and view all the answers

    What side effects may be associated with the use of narcotic analgesics?

    <p>Constipation and lightheadedness</p> Signup and view all the answers

    Which mechanism is primarily involved in the prevention of neurotransmitter release during seizures?

    <p>Inhibition of Na+ entry into the cell</p> Signup and view all the answers

    What is a significant side effect associated with the use of hydantoins for seizure treatment?

    <p>Nystagmus</p> Signup and view all the answers

    Which of the following is NOT a common indication for sedatives and hypnotics?

    <p>Prevention of epileptic seizures</p> Signup and view all the answers

    Which of the following side effects is least likely associated with benzodiazepines used for seizures?

    <p>Hypertension</p> Signup and view all the answers

    What characterizes nystagmus in patients affected by seizure medications?

    <p>Repetitive eye movements</p> Signup and view all the answers

    Which of the following local anesthetics is known for its potency and is commonly used in ophthalmology?

    <p>Tetracaine</p> Signup and view all the answers

    What is a major disadvantage associated with the use of local anesthesia?

    <p>Potential for allergic reactions</p> Signup and view all the answers

    Local anesthetics can stay in the body for varying durations. What is the maximum time some anesthetics may remain effective?

    <p>24 hours</p> Signup and view all the answers

    How do drugs that alter synaptic transmission typically function?

    <p>They selectively influence specific neurotransmitters</p> Signup and view all the answers

    Which of the following is considered an advantage of using local anesthesia during procedures?

    <p>Patients are awake during the treatment</p> Signup and view all the answers

    What is the primary mechanism by which most neuropharmacological agents operate?

    <p>Influencing synaptic transmission</p> Signup and view all the answers

    Which of the following drugs is a common local anesthetic classified as an amino amide?

    <p>Bupivacaine</p> Signup and view all the answers

    What is a significant consequence of the nonselective inhibition of axonal conduction caused by certain drugs?

    <p>Inability to produce selective effects</p> Signup and view all the answers

    How do local anesthetics primarily achieve their effect in the body?

    <p>By blocking action potentials in sensory nerves</p> Signup and view all the answers

    What distinguishes drugs that alter axonal conduction from those that affect synaptic transmission?

    <p>Their impact on all nerves equally</p> Signup and view all the answers

    What occurs in step 5 of synaptic transmission?

    <p>Removal of the transmitter from the synaptic gap</p> Signup and view all the answers

    Which of the following events directly follows the fusion of vesicles with the terminal membrane?

    <p>Transmitter release into the synaptic gap</p> Signup and view all the answers

    Which common side effect occurs after the application of local anesthetics?

    <p>Loss of pain sensation in the affected area</p> Signup and view all the answers

    Which mechanism primarily terminates the action of neurotransmitters in the synaptic gap?

    <p>Enzymatic degradation</p> Signup and view all the answers

    What characteristic of axonal conduction contributes to the nonselective nature of drugs that alter this process?

    <p>Similar processes of impulse conduction across neurons</p> Signup and view all the answers

    Which of the following agents is least likely to impact axonal conduction directly?

    <p>Neuropeptide modulators</p> Signup and view all the answers

    During which step of synaptic transmission does the binding of the transmitter to the receptor occur?

    <p>Step 4</p> Signup and view all the answers

    What is a primary characteristic of transmitter molecules in the synaptic transmission process?

    <p>They diffuse across the synaptic gap to bind with receptors.</p> Signup and view all the answers

    What role do neuropharmacological drugs play in synaptic transmission?

    <p>They alter receptor activity on target cells.</p> Signup and view all the answers

    In the synaptic transmission process, which statement about transmitter storage is accurate?

    <p>Transmitter is stored in vesicles until action potential arrival.</p> Signup and view all the answers

    Which process does NOT contribute to the termination of neurotransmitter action in the synaptic gap?

    <p>Increased receptor activity</p> Signup and view all the answers

    What role does serotonin play in the human body?

    <p>Controls mood, anxiety, sleep patterns, appetite, and pain</p> Signup and view all the answers

    What is the primary effect of dopamine in the brain?

    <p>Enhances feelings of pleasure and motivation</p> Signup and view all the answers

    Which neurotransmitter is primarily responsible for the 'fight-or-flight' response?

    <p>Epinephrine</p> Signup and view all the answers

    How do stimulant medications primarily affect norepinephrine levels?

    <p>By increasing its release and levels</p> Signup and view all the answers

    What condition is most commonly associated with a dysfunction in dopamine levels?

    <p>Parkinson's disease</p> Signup and view all the answers

    What role does histamine play in the body?

    <p>Controls feeding behavior and wakefulness</p> Signup and view all the answers

    Which of the following best describes norepinephrine's functions?

    <p>Functions as both a neurotransmitter and a hormone related to alertness</p> Signup and view all the answers

    What is the relationship between dopamine and highly addictive drugs?

    <p>They enhance dopamine release, reinforcing reward behavior</p> Signup and view all the answers

    What role do local anesthetics play in neuronal signaling, and how do they affect pain perception?

    <p>Local anesthetics decrease axonal conduction in nerves, preventing pain signals from reaching the brain.</p> Signup and view all the answers

    Identify a common type of local anesthetic and describe its application in medical procedures.

    <p>Lidocaine is a common local anesthetic used to numb tissues in various medical procedures.</p> Signup and view all the answers

    What is the consequence of nonselective inhibition of axonal conduction by certain neuropharmacological agents?

    <p>It results in a lack of selective effects, affecting all nerves that the drug reaches.</p> Signup and view all the answers

    Explain how neuropharmacological agents alternately influence synaptic transmission compared to axonal conduction.

    <p>Most neuropharmacological agents act by altering synaptic transmission rather than directly affecting axonal conduction.</p> Signup and view all the answers

    What potential risks are associated with the nonselective nature of drugs affecting axonal conduction?

    <p>The risk includes widespread nerve function impairment, leading to unintended effects in multiple systems.</p> Signup and view all the answers

    How do local anesthetics allow some sensory perceptions like pressure or movement despite blocking pain?

    <p>They selectively block pain transmission while sparing other sensory pathways, such as those for pressure.</p> Signup and view all the answers

    What is the main mechanism through which most neuropharmacological agents enhance our understanding of normal neuronal function?

    <p>They modify neurotransmitter action to reveal the underlying processes of synaptic communications.</p> Signup and view all the answers

    Name two classes of local anesthetics and provide an example of each.

    <p>Amino amides and amino esters; examples include bupivacaine (amide) and procaine (ester).</p> Signup and view all the answers

    What role does the limbic system play in emotional and behavioral responses?

    <p>The limbic system is involved in regulating emotional and behavioral responses, crucial for survival activities like feeding, reproduction, and the fight or flight response.</p> Signup and view all the answers

    How do anxiolytics influence GABA levels in the brain?

    <p>Anxiolytics increase GABA levels, which leads to altered responses in the limbic center and promotes calming effects.</p> Signup and view all the answers

    What is the relationship between opioid receptors and pain response?

    <p>Opioid receptors bind to substances that depress or alter the body's pain response, often producing a euphoric effect.</p> Signup and view all the answers

    What distinguishes opioid agonist-antagonists from full opioid agonists?

    <p>Opioid agonist-antagonists bind to opioid receptors but exhibit mild narcotic antagonist actions, providing pain relief with fewer euphoria effects.</p> Signup and view all the answers

    What common side effects are associated with the use of opioid agonists?

    <p>Common side effects include dizziness, lightheadedness, and constipation.</p> Signup and view all the answers

    Describe the euphoric effect in relation to opioid use.

    <p>The euphoric effect refers to a feeling of intense excitement and happiness that many opioid agonists provide alongside pain relief.</p> Signup and view all the answers

    What impact does blocking dopamine receptors have in the brain?

    <p>Blocking dopamine receptors can reduce responsiveness and alter emotional responses, affecting motivation and reward pathways.</p> Signup and view all the answers

    Why is the opioid receptor considered a G protein-coupled receptor?

    <p>The opioid receptor is a G protein-coupled receptor because it interacts with G proteins to mediate various physiological responses to drugs, hormones, and neurotransmitters.</p> Signup and view all the answers

    What is the mechanism of action for cholinergic agonists?

    <p>Cholinergic agonists activate the cholinergic system by inducing parasympathetic activity or inhibiting acetylcholinesterase.</p> Signup and view all the answers

    What condition is primarily indicated for cholinergic agents?

    <p>Cholinergic agents are primarily indicated for glaucoma and myasthenia gravis.</p> Signup and view all the answers

    Describe the role of acetylcholinesterase in cholinergic synaptic transmission.

    <p>Acetylcholinesterase breaks down acetylcholine in the synaptic cleft, terminating its action and preventing overstimulation.</p> Signup and view all the answers

    How is bradycardia defined in adults?

    <p>Bradycardia is defined as a heart rate of fewer than 60 beats per minute in adults.</p> Signup and view all the answers

    What are common symptoms of bradyarrhythmias?

    <p>Common symptoms of bradyarrhythmias include shortness of breath, fatigue, and dizziness.</p> Signup and view all the answers

    What is the main consequence of excessive activation of the cholinergic system?

    <p>Excessive activation of the cholinergic system can lead to side effects such as hypotension, bradycardia, and gastrointestinal distress.</p> Signup and view all the answers

    Identify one side effect of cholinergic antagonists.

    <p>One side effect of cholinergic antagonists is dry mouth.</p> Signup and view all the answers

    How does myasthenia gravis affect muscle function?

    <p>Myasthenia gravis causes weakness and rapid fatigue in voluntary muscles due to impaired communication between nerves and muscles.</p> Signup and view all the answers

    What is the typical heart rate range for adults, and how does tachycardia differ from this range?

    <p>The typical adult heart rate ranges from 60 to 100 beats per minute; tachycardia is defined as a heart rate over 100 beats per minute.</p> Signup and view all the answers

    What are the therapeutic uses of adrenergic agents?

    <p>Adrenergic agents are used to stimulate the sympathetic nervous system for conditions like asthma and heart failure.</p> Signup and view all the answers

    What are the three ways through which neurotransmitter transmission is terminated at the synaptic gap?

    <p>By reuptake into the nerve terminal, enzymatic degradation, or diffusion away from the gap.</p> Signup and view all the answers

    How do neuropharmacological drugs modulate receptor activity during synaptic transmission?

    <p>They alter the binding or responsiveness of neurotransmitters to their receptors on target cells.</p> Signup and view all the answers

    Describe the role of vesicles in the process of synaptic transmission.

    <p>Vesicles store neurotransmitters until an action potential triggers their release into the synaptic gap.</p> Signup and view all the answers

    What occurs at the postsynaptic cell when a neurotransmitter binds to its receptor?

    <p>The binding causes a biochemical response that may lead to the generation of an action potential in the postsynaptic cell.</p> Signup and view all the answers

    Identify the first step of synaptic transmission involving transmitter molecules.

    <p>Transmitter synthesis from precursor molecules is the initial step.</p> Signup and view all the answers

    What is the significance of receptor binding in the context of neurotransmitter action?

    <p>Receptor binding initiates a specific response in the target cell, determining the effect of the neurotransmitter.</p> Signup and view all the answers

    Explain how the arrival of an action potential influences synaptic transmission.

    <p>The action potential triggers vesicles to fuse with the terminal membrane and release neurotransmitters into the synaptic gap.</p> Signup and view all the answers

    What role do precursor molecules play in neurotransmitter synthesis?

    <p>Precursor molecules are necessary for synthesizing neurotransmitters needed for synaptic transmission.</p> Signup and view all the answers

    What condition characterized by involuntary movements may develop due to antipsychotic medication use?

    <p>Tardive dyskinesia</p> Signup and view all the answers

    Identify a common psychological effect associated with both psychosis and severe alcoholism.

    <p>Hallucinations</p> Signup and view all the answers

    Which class of drugs is indicated for treating conditions like psychosis and can cause extrapyramidal reactions?

    <p>Antipsychotic drugs</p> Signup and view all the answers

    What are two common side effects of antipsychotic medications that affect movement?

    <p>Extrapyramidal reactions and Tardive dyskinesia</p> Signup and view all the answers

    Name a significant risk factor associated with chronic alcoholism that impacts personal relationships.

    <p>Inability to stop drinking</p> Signup and view all the answers

    What physiological system do anxiolytics primarily affect?

    <p>Limbic or subcortical areas of the brain</p> Signup and view all the answers

    List one example of an antipsychotic medication mentioned in the content.

    <p>Chlorpromazine</p> Signup and view all the answers

    What type of reactions can occur as a result of taking dopamine antagonists prescribed for psychosis?

    <p>Extrapyramidal reactions</p> Signup and view all the answers

    Study Notes

    Synaptic Transmission

    • Neurons alter receptor activity by releasing neurotransmitters
    • Neurotransmitters diffuse across the synapse and bind to receptors on the postsynaptic cell
    • Neuropharmacological drugs work by altering receptor activity on target cells

    Steps of Synaptic Transmission

    • Step 1: Transmitter Synthesis
      • Neurotransmitter synthesis is from precursor molecules (Q, R, and S)
    • Step 2: Transmitter Storage
      • Neurotransmitters are stored in vesicles
    • Step 3: Transmitter Release
      • Action potentials cause vesicles to fuse with the terminal membrane
      • Neurotransmitters are released into the synaptic gap
    • Step 4: Receptor Binding
      • Neurotransmitter binds to a receptor on the postsynaptic cell, causing a response
    • Step 5: Termination of Transmission
      • Neurotransmitter dissociates from the receptor
      • Removal from the synaptic gap can occur by:
        • Reuptake into the nerve terminal
        • Enzymatic degradation
        • Diffusion away from the gap

    Effects of Drugs on Synaptic Transmission

    • Cocaine and Amphetamine
      • Cause neurons to release abnormally large amounts of neurotransmitters
      • Interfere with transporters, preventing normal recycling of neurotransmitters
      • Amplifies or disrupts communication between neurons
    • Phencyclidine and Related Drugs
      • Inhibit the reuptake of monoamine neurotransmitters
      • Mind-altering effects, causing distorted perceptions, hallucinations, and violent behavior
      • Adverse effects include increased risk of suicide, coma, addiction, and seizures

    Central Nervous System Pharmacology

    • Sigma (σ) receptors
      • Bind to a variety of pharmacologically active drugs
    • Mu (μ) receptors
      • Involved in neuromodulating physiological functions
      • Act as an inbox for messages in the form of sugars, lipids, peptides, and proteins
    • Limbic System
      • Involved in emotional and behavioral responses, especially for survival functions

    Analgesics

    • Opioid Agonists
      • Mechanism - Bind to opioid receptor sites, depressing or altering the pain response; also provide a euphoric effect
      • Indication - Pain
      • Side Effects - Dizziness, lightheadedness, constipation
      • Examples - Codeine, Hydromorphone, Oxycodone, Propoxyphene, Morphine
    • Opioid Agonist-Antagonists
      • Mechanism - Bind to opioid receptor sites with a mild narcotic antagonist action, preventing further binding
      • Indication - Pain
      • Side Effects - Dizziness, lightheadedness, constipation
      • Examples - Buprenorphine, Butorphanol, Nalbuphine, Pentazacine
    • Narcotic Antagonists
      • Used to:
        • Reverse toxicity associated with opioid agonist analgesic overdose
        • Prevent relapse in opioid agonist analgesic-dependent patients
    • Non-Opioid Analgesics
      • Mechanism - Inhibit prostaglandin synthesis, increasing the body's response to pain; also have an anti-pyretic effect
      • Indication - Pain, fever
      • Side Effects - GI problems, headache, dizziness
      • Examples - Aspirin, Acetaminophen, Ibuprofen, Naproxen sodium

    Prostaglandins

    • Hormone-like substances affecting inflammation, pain, and uterine contractions

    Anti-Pyretic Effect

    • Drugs used to reduce fever

    Peripheral Vasodilation

    • Dilation of blood vessels in the distal parts of the vascular system
    • Lowers blood pressure

    Thermoregulatory Center

    • The human body's thermostat
    • Located in the preoptic area of the hypothalamus

    Sedatives

    • Cause calmness, relaxation, or sleepiness
    • Used in medical or surgical procedures and to cope with stressful events

    Alcohol Withdrawal Symptoms

    • Low mood or depression
    • Shakiness or trembling
    • Anxiety or jumpiness
    • Loss of appetite
    • Fatigue

    Anti-Depressants

    • Tricyclic Antidepressants (TCAs)
      • Mechanism - Increase norepinephrine and serotonin levels by inhibiting their reabsorption
    • Monoamine Oxidase Inhibitors (MAOIs)
      • Mechanism - Prevent the metabolism of neurotransmitters in the central nervous system
    • Indication - Depression
    • Side Effects - Hypotension, tachycardia, blurred vision, dry mouth, restlessness, insomnia, nausea, and vomiting
    • Examples - TCAs & Others - Amitriptyline, Clomipramine, Doxepin, Buproprion
    • Examples - MAO Is - Phenelzine, Tranylcypromine

    Antipsychotics

    • Mechanism - Block postsynaptic dopamine receptors, inhibiting nerve impulse transmission
    • Indication - Psychosis
    • Side Effects - Extrapyramidal symptoms, tardive dyskinesia

    Seizures

    • A burst of uncontrolled electrical activity between brain cells
    • Causes temporary abnormalities in muscle tone or movements
      • Results in twitching and stiffness
    • Causes abnormal sensations, behaviors and states of awareness

    Nystagmus

    • A vision condition that causes repetitive and uncontrolled movements of the eyes
      • Results in reduced vision and depth perception
      • Affects balance and coordination
    • Involuntary eye movements can range from up and down, side to side, or in a circular pattern

    Sedatives and Hypnotics

    • Decrease the amount of neurotransmissions from the thalamus and the cortex of the brain
    • Wide ranging indications:
      • Sedation
      • Insomnia
      • Treatment of alcohol withdrawal symptoms

    Common Acting Mechanisms for Neuropharmacological Agents

    • Influence the process under neuronal control
    • Alter one of the two basic neuronal activities:
      • Synaptic transmission
      • Axonal conduction
    • Most neuropharmacological agents act by altering synaptic transmission

    Drugs that Alter Axonal Conduction

    • Nonselective inhibition of axonal conduction
    • Suppress transmission in any nerve that they reach
    • The process of impulse conduction along the axon is essentially the same for all neurons
    • Cannot produce selective effects
    • Affect conduction in all nerves of access

    Drugs that Alter Axonal Conduction - Local Anesthetics

    • Stop nerves in part of the body from sending signals to the brain
    • Unable to feel pain after application of local anesthetic
    • May still feel some pressure or movement
    • Work by decreasing axonal conduction
    • Nonselective inhibition of axonal conduction
    • Suppress transmission in any nerve they reach
    • Valuable but with limited indications

    Drugs Used as Local Anesthetic

    • Amino amides:
      • Commonly used: bupivacaine, etidocaine, lidocaine, mepivacaine, prilocaine, ropivacaine, etc.
    • Amino esters:
      • Commonly used: benzocaine, chloroprocaine, cocaine, procaine, tetracaine

    How Long Does Local Anaesthetic Stay in Your System?

    • Some local anaesthetics last longer than others
    • Some can stay in the body up to 18 hours after being administered
    • Some anaesthetic can even stay in the body for up to 24 hours
    • The duration of effects depends on the exact drug used and how much is given

    An Example of a Strong Local Anesthetic: Tetracaine

    • One of the most potent anesthetics
    • Of the ester-type anesthetic group
    • Widely applied in ophthalmology
      • As a topical anesthetic agent

    Advantages and Disadvantages of Local Anesthesia

    • Advantages:
      • Convenience, simplicity and safety
      • Patient is awake during the treatment
      • Few postoperative complications
      • Minimizes the affect to normal physiological condition of the patients
    • Disadvantages:
      • Allergic reaction in rare situations
      • Some patients may develop cardiac arrest (heart stops pumping blood around the body) in rare cases.

    Drugs that Alter Synaptic Transmission

    • Synapses, unlike axons, differ from one another
    • Synapses of different sites have different transmitters
    • Drugs can selectively influence a specific type of neurotransmitter, alter one neuronally regulated process, while leaving most others unchanged.
    • Effects are thus highly selective and this kind of drug has many uses

    Role of Receptors in Synaptic Transmission

    • Neurons in synapses alter receptor activity on the target cell by releasing transmitter molecules
    • These transmitter molecules diffuse across the synaptic gap and bind to receptors on the postsynaptic cell.
    • Neuropharmacological drugs act by altering the receptor activity on target cells.

    Synaptic Transmission Steps

    • Step 1: Transmitter Synthesis:
      • Synthesis of transmitter (T) from some precursor molecules (Q, R, and S)
    • Step 2: Transmitter Storage:
      • Transmitter (T) stored in vesicles
    • Step 3: Transmitter Release:
      • When an action potential arrives, the vesicles fuse with terminal membrane and release the transmitter into the synaptic gap

    Synaptic Transmission Steps (Continue)

    • Step 4: Receptor Binding:
      • On the postsynaptic cell, the transmitter binds reversibly to the receptor that causes a response in the cell.
    • Step 5: Termination of Transmission:
      • Transmitter dissociates from the receptor and is removed from the synaptic gap by:
        • Reuptake into the nerve terminal
        • Enzymatic degradation
        • Diffusion away from the gap

    Effects of Drugs on Steps of Synaptic Transmission

    • Serotonin:
      • Calming chemical: Regulates mood, anxiety, sleep patterns, appetite, sexuality, and pain.
      • Serotonin imbalance: Depression, anxiety, depression, and chronic pain.
      • Medications: Increase the levels of Serotonin by inhibiting the reuptake after their functioning at the postsynaptic receptor sites.
      • Facilitating memory and assists in decision-making behavior.

    Monoamines Neurotransmitters (Continue) - Dopamine

    • Acts as "pleasure chemical" - Released when receiving reward in response to behavior (food, drugs).
    • Involves feelings of pleasure, focus of attention, mood, sleep, concentration, memory, and motivation.
    • Diseases relating to dysfunctions of the dopamine system - Parkinson’s disease, etc.
    • Some highly addictive drugs (cocaine, amphetamines, etc.) - Act on brain's dopamine circuits.

    Monoamines Neurotransmitters (Continue) - Histamine

    • Regulates body functions such as wakefulness, feeding behavior, and motivation.

    Monoamines Neurotransmitters (Continue) - Epinephrine

    • Also called adrenaline
    • Together with norepinephrine - Responsible for the “fight-or-flight response” to fear and stress
    • Activating the sympathetic nervous system.

    Monoamines Neurotransmitters (Continue) - Norepinephrine:

    • Also called noradrenalin.
    • Linked to memory, mood, and stress.
    • Increases alertness, heart rate, blood pressure, and attention.
    • Both a neurotransmitter and a hormone.
    • Many medications such as stimulants and depression medications:
      • Increase norepinephrine to promote concentration and focus.
      • For reducing symptoms of depression and treating ADHD.

    What is ADHD?

    • Refer to further research online.

    Nervous System

    • Neurological and psychiatric disorders are treated with medications that target specific parts of the nervous system.
    • The nervous system is composed of neurons, which transmit information through axonal conduction and synaptic transmission.
    • Axonal conduction is the process of transmitting electrical impulses along the axon of a neuron.

    Axonal Conduction

    • Most neuropharmacological agents alter synaptic transmission rather than axonal conduction.
    • Local anesthetics, like bupivacaine, lidocaine, and prilocaine, are examples of drugs that target axonal conduction.
    • Local anesthetics work by decreasing the electrical activity of certain nerves. They are valuable drugs but only effective for specific conditions.

    Synaptic Transmission

    • Synaptic transmission involves the release of neurotransmitters from a presynaptic neuron, which bind to receptors on a postsynaptic neuron.
    • These drugs act by altering the activity of receptors on target cells.

    Steps of Synaptic Transmission

    • Step 1: Transmitter Synthesis: The neurotransmitter is produced from precursor molecules.
    • Step 2: Transmitter Storage: The neurotransmitter is stored in vesicles.
    • Step 3: Transmitter Release: The neurotransmitter is released into the synaptic gap through the fusion of vesicles with the terminal membrane.
    • Step 4: Receptor Binding: The neurotransmitter binds to receptors on the postsynaptic cell.
    • Step 5: Termination of Transmission: The neurotransmitter is removed from the synaptic gap by reuptake, enzyme degradation, or diffusion.

    Drugs Affecting Synaptic Transmission

    • Medications for neurologic and psychiatric disorders can act at different stages of synaptic transmission.
    • These drugs modulate the levels of neurotransmitters, including dopamine, GABA, and acetylcholine.

    Central Nervous System Pharmacology - Analgesics

    • Opioid Agonists like codeine, morphine, and oxycodone, bind to opioid receptors.
    • Opioid antagonists like naloxone can block the effects of opioid agonists.
    • Opioid Agonist-Antagonists provide analgesia with fewer side effects compared to pure agonists.

    Central Nervous System Pharmacology - Cholinergic Agents

    • Cholinergic Agonists activate the cholinergic system by stimulating the release of acetylcholine or inhibiting the enzyme acetylcholinesterase.
    • Cholinergic Antagonists block the effects of acetylcholine on muscarinic receptors.

    Central Nervous System Pharmacology - Adrenergic Agents

    • Adrenergic Agonists stimulate the alpha and beta receptors of the sympathetic nervous system.

    Drugs of Abuse

    • The effects of drugs of abuse can be altered by manipulating different stages of synaptic transmission.
    • Many drugs of abuse influence the reward pathway of the brain.

    Neuropharmacology for Understanding the Nervous System

    • Understanding the mechanisms of drug action can shed light on normal nervous system function.
    • By observing the effects of drugs on receptors, signaling pathways, and neurotransmitter systems, researchers gain insights into the complex processes that govern behavior, perception, and cognition.

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    Principles Of Neuropharmacology PDF

    Description

    Explore the fascinating process of synaptic transmission in neurons. This quiz covers neurotransmitter synthesis, storage, release, binding, and termination of transmission. Test your understanding of how neuropharmacological drugs influence receptor activity!

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