Psyc 4, Ch 5

  1. Neurotransmitters
    • ...are made in neurons
    • ...found in neurons
    • ...release a chemical when stimulated
    • with receptor and produce a biological response
    • ...have the same response when experimented with/on
    • inactivated after released from the receptor

    Play a key role in everything we do!
  2. Types of Neurotrasmitters
    1. Small-Molecule Transmitters

    2. Neuropeptides

    3. Transmitter Gasses
  3. How Neurotrasmitters Interact
    1. Release and respond to several neurotransmitters

    2. Bind with different receptors

    3. Give either excitatory or inhibitory signals

    4. Some trasmit very rapid and brief signals; others transmit slower, longer lasting signals
  4. How Neurotrasmitters Are Made
    Precursor molecules are absorbed in the digestive tract and delivered to neurons through blood. They are made into neurotrasmitters through an assembyline worked by enzymes.

    A diet that has high/low concentrations of presursor molecules may affect what neurotrasmitters are produced.
  5. Working Together:
    Neurons, Neurotrasmitters, Synapses, and Receptors
    The process of transmitting signals and their transmition is influenced by a variety of factors, including learning, maturation, stress, diet, drugs, and diseases.

    Changes in these can alter the rate of production/release, number and sensitivity of receptors, firing threshold, firing rate, and/or rate of inactivation.

    Dysfuctions - if processes are not normal, physical and emotional well-being, cognition, and behavior can be affected.
  6. Acetylcholine (ACh)
    Made in the CNS and PNS

    Roles - primary neurotrasmitter in muscle movement; key role in memory and cognitive functioning; prominent role in triggering REM sleep (dreaming)
  7. Serotonin (ST or 5-HT)
    Produced throughout the brain

    Regulates/Keeps in Order: impulses, thoughts, emotions/moods, appetite, sleep, sex, pain, social behavior, aggression

    Precursor molecule - tryptophan
  8. Dopamine (DA)
    Involved in: movement, attention, learning, perception, cognition, motivation, pleasure, and reinforcing the effects of certain drugs
  9. Norepinephrine (NE)
    Derived from DA and produced in the brain stem

    Increases attention and arousal: increases alterness; accelerates thinking; stimulates fight/flight; increases mental energy, motivation, and excitment; promotes wakefulness; regulates mood; enhaces learning and memory; helps stimulate pleasure and reward; organizes the brain/body to deal with danger
  10. Inhibitory Neurotransmitters
    Most brain activity is inhibitory

    Play a key role in "braking" - suppress the activity of neurons

    Two are especially important...
  11. GABA
    Most important inhibitory neurotrasmitter in the CNS; involved in almost every behavior

    Roles - Reduces anxiety, promotes relaxation and sleep, reduces blood pressure and heart rate, elevates the pain threshold, promotes fine motor function, reduces seizure activity
  12. Glycine
    Found mostly in the spinal cord and lower portions of the brain

    Low levels of glycine cause muscles to contract and spasm
  13. Excitatory Neurotransmitters
    Rapidly depolarize neurons, lower the firing threshold, and increase firing rates

    Principle = Glutamate - in the CNS; increases alterness, attention, arousal, and memory; excessive levels caused by oxygen deprivation can cause seizures or psychotic disorders
  14. Seizures
    Groups of neurons in part of the brain start rapidly firing in sync with one another instead of is established patterns

    Triggers - lack of sleep, psychological stress, hormone changes, sensory stimuli (ex. flashing lights)

    Causes - head injury, brain tumors, strokes, brain infections, abnormal brain development, degenerative brain disease
  15. Neuropeptides
    Chemical compounds made of short amino acid chains that modulate the transmission of signals at the syapse, influence the firing rate, and help or inhibitt release of neurotransmitters

    Can work as neuromodulators, hormones, or neurotrasmittes

    Must be removed from the synapse after use but they stay active longer than neurotrasmitters
  16. Roles of Neuropeptides
    • Stimulate feelings of well-being
    • Promote emotional balance
    • Reduce stress
    • Stimulate pleasure, reward, and euphoria
    • Reduce alcohol/drug appetite
    • Regulate hunger and thirst
    • Enhance cognition
    • Promote attachment
    • Regulate sex drive
  17. Types of Chemical Messengers
    1. Neurotransmitters - released into the synaptic gap

    2. Hormones - released into the blood stream

    3. Neuromodulators - modulate the firing rate of other neurotransmitters
  18. Phenylthylamine (PEA)
    One of the primary chemicals of infatuation, lust, and romatic love

    Stimulates infatuation, lust, appetite suppressant, orgasm, ovulation

    "Love potion" of PEA + DA + NE is potent but does not last long
  19. Oxytocin
    Promotes feelings of attachment and bonding behavior

    Stimulates skin sensitivity and desire for touch and affectionate behavior

    Associated with "true" love

    High levels - monogamous; Low levels - promiscuous
  20. Gaseous Neurotransmitters
    Some soluable gasses function as neurotransmitters, but they function differently: exit neuron's membrane by diffusion and enter the receing neuron's membrane the same way and act upon receptors inside the neuron

    Two types...
  21. Nitric Oxide (NO)
    In CNS and PNS

    Involved in memory formation, disgestion, penile erection, and influences the activity of other neurotrasmitters (ex. glutamate)
  22. Carbon Monoxide (CO)
    Seems to play an important role in modulating the production of neurotransmitters
Card Set
Psyc 4, Ch 5
psyc 3, quiz 2