PSYCH 454 - Neuroscience III

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PSYCH 454 - Neuroscience III
2011-06-20 19:36:50
catecholamines dopamine norepinephrine serotonin acetylcholine

Neurotransmitters (Dopamine, Norepinephrine, Serotonin, & Acetylcholine)
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  1. Sensitization to drugs of abuse is initiated in the _________, this results in neural reorganization that is expressed in the __________ and manifested as a change in behavior
    Ventral Tegmental Area; Nucleus Accumbens
  2. What are the three catecholamine neurotransmitters? What do they all have in common structurally?
    • Dopamine, norepinephrine, epinephrine
    • All are composed of a catechol nucleas and an amine group
  3. The first precursor molecule in the synthesis of dopamine and norepinephrine is _________, this molecule is converted to __________ by the enzyme __________.
    Tyrosine; L-DOPA, tyrosine hydroxylase
  4. What is the rate limiting step in catecholamine synthesis?
    The conversion of tyrosine to L-DOPA by tyrosine hydroxylase
  5. L-DOPA is converted to dopamine by the enzyme _________________, dopamine is then converted to norepinephrine in noradrenergic neurons by the enzyme ________________.
    Aromatic amino acid decarboxylase; Dopamine B-hydroxylase
  6. When sufficient amounts of dopamine or norepinephrine have been synthesized these neurotransmitters will inhibit the activity of the enzyme __________. This is a classic example of _______________.
    Tyrosine hydroxylase; Negative feedback
  7. Newly synthesized catecholamines are stored in vessicles by a protein found in the vessicle membrane called ________________. This protein is called _________ in the brain and _________ in the adrenal medulla
    Vesicular monoamine transporter protein; VMAT1; VMAT2
  8. T/F The amount of neurotransmitter stored in a vessicle varies from vessicle to vessicle.
    False, it is always the same
  9. An experimental drug called _________ blocks VMAT1 preventing transport of NE and DA into vessicles. This causes sensations of ______/______ in the animal who has taken it.
    Reserpine; sedation/depression
  10. Pre-synaptic autoreceptors reduce calcium influx into the cell when they bind neurotransmitter inhibiting further release into the synapse. The dopamine autoreceptor is called _________ and the norepinephrine autoreceptor is called ________
    D2; α2
  11. Cathecholamines that are released into the synapse are broken down by two different enzymes. One is called ________ and the other is called _________.
    Monoamine oxidase (MAO); catechol-O-methyltransferase (COMT)
  12. T/F MAO is present in the pre and post-synaptic neurons while COMT is only found post-synaptically.
  13. What is volume transmission? What does it allow for?
    Volume transmission occurs when neurotransmitter is released along the axon into the extracellular fluid (no traditional synapse); This creates a neurotransmitter "bath" and allows for stronger, faster, and more global communication.
  14. What are the three main dopaminergic pathways?
    Nigrostriatal pathway; mesocortical pathway; mesolimbic pathway
  15. Which dopaminergic pathway is important for intiating movement.
    The nigrostriatal pathway
  16. The dopaminergic mesolimbic pathway projects from the __________ to limbic areas such as the ___________. This pathway is an important part of the brain's __________.
    Ventral tegmental area; nucleus accumbens; reward system
  17. The dopaminergic mesocortical pathway is crucial for ___________, ___________, & ____________. This pathway projects from the ___________ to the ____________ and the ______________.
    • Consciousness; learning/memory, decision making
    • Ventral tegmental area; cerebral cortex; hippocampus
  18. T/F Dopamine has both ionotropic an metabotropic receptors
    False; metabotropic
  19. For the purpose of this class there are two different families of dopamine receptors; the ______ family and the ______ family.
    D1; D2
  20. Activation of the D1 dopamine receptor ________ release of the secondary messenger ______, while activation of the D2 dopamine receptor _______ release of ________.
    Stimulates; cAMP; inhibits; cAMP
  21. Activeation of the D2 receptor opens _____________ leading to cell _________.
    Potassiums channels; hyperpolarization
  22. Dopaminergic neurons signal ______________ and they also learn to signal a conditioned stimulus that is _________________.
    An unexpected reward; predictive of a reward
  23. T/F Dopaminergic neurons also signal and error (expected reward not present) through depression of neuronal firing
  24. Noradrenergic neurons are found in the ___________ of the pons. In this location there are roughly _________ noradrenergic neurons, and they project to ____________
    Locus coeruleus; 3,000; to the entire brain
  25. In the peripheral nervous system norepinephrine is a key component of the ___________ of the autonomic nervous system and the ___________ response.
    Sympathetic; fight or flight
  26. Which neurotransmitter is responsible for alerting us to important stimuli and maintaining vigilance?
  27. What are the two families of noradrenergic receptors?
    α and β
  28. The ____ and ____ adrenergic receptors act like the dopamine D1 receptor by __________ levels of cAMP in the post-synaptic cell
    β1; β2; increasing
  29. What noradrenergic receptor is similar to the dopamine D2 receptor? Activation of this receptor casues what effect in the post-synaptic cell?
    α2; decreased levels of cAMP
  30. The α1 noradrenergic recepotor uses ____________ as its secondary messenger, and this messenger leads to ____________.
    Phosphoinositide; increased calcium in the cell
  31. β1 and β2 receptors ________ cAMP, while α2 ________ cAMP
    Stimulate; inhibits
  32. The noradrenergic β receptor agonist discussed in class is called ____________ and the α1 receptor agonist is called _____________.
    Isoproterenol; phenylephrine
  33. Phenylephrine is a ___ agonist and isoproterenol is a ___ agonist; use of either of these agonists produces ____________ in the animal.
    α1; β; wakefulness
  34. The two primary components of acetylcholine are _______ and _______.
    Choline; acetyl CoA
  35. Choline is found in __________, and acetyl CoA is a ___________; these two components are combined to form acetylcholine by the enzyme ____________.
    Dietary fats; metabolite of sugar & fat; choline acetyltransferase
  36. Acetylcholine is packaged into vessicles by _____________________; the drug ________ (like reserpine for the monoamines) can be used to block this protein.
    Vesicular acetylcholine transporter protein; vesamicol
  37. What are the names of the two acetylcholine receptors? What type of receptor is each?
    Nicotinic (iontropic); Muscarinic (metabotropic)
  38. The enzyme ___________ is responsible for breaking down acetylcholine in the synapse. Once broken down, _______ is the component only that the cell reuptakes.
    Acetylcholinesterase; choline
  39. Acetylcholine is rapidly metabolized especially when it is released at a ________________. This allows for ____________.
    Neuromuscular junction; precise control of the muscles
  40. __________________ is an autoimmune disorder where antibodies bind to acetylcholine receptors and degrade them resulting in _____________, __________, and eventually ___________.
    Myasthenia gravis; progressive muscle atrophy; respiratory depression; death
  41. What effect does stress have on the blood brain barrier?
    It makes is a less effective barrier
  42. During the Gulf War soldiers were given pyridostigmine, an ______________ to protect them from nerve gas.
    Acetylcholinesterase inhibitor
  43. In the ______________ of the autonomic nervous system both preganglionic and ganglionic neurons use acetylcholine as their primary neurotransmitter; In the _______________ acetylcholine is only used by preganglionic neurons while ______________ is used by ganglionic neurons.
    Parasympathetic division; Sympathetic division; norepinephrine
  44. What brain system uses acetylcholine as its primary neurotransmitter and is used for higher level cognitive functioning such as learning, memory, and attention?
    The basal forebrain cholinergic system (BFCS)
  45. Which acetylcholine receptor is ionotropic, composed of 5 protein subunits, and most highly concentrated at neuromuscular junctions where it mediates fast excitatory responses in the autonomic nervous system?
    Nicotinic receptor
  46. Nicotinic receptors can become __________ desensitized to _____________ when they are continuously exposed to it.
    Temporarily; acetylcholine
  47. Muscarine is an agonist of the muscarinic receptor and is naturally found in the ___________.
    Fly agaric mushroom
  48. T/F Muscarinic receptors are ionotropic.
  49. Overall the muscarinic receptors is ____________. It can act on effector enzymes to ________ levels of cAMP or it can stimulate the opening of _____________ resulting in hyperpolarization.
    Inhibitory; decrease; K+ ion channels
  50. The muscarinic receptor has __ subtypes (__-__). Research has shown that the __ receptor is required to feel the rewarding effects of ________.
    5; M1-M5; M5; opiates
  51. ____________ is the first precursor molecule in the synthesis of serotonin.
  52. In the ______________ step of serotonin synthesis tryptophan is converted into ________ using the enzyme ____________.
    Rate-limiting; 5-HTP; tyrptophan hydroxylase
  53. 5-HTP is converted to serotonin by the enzyme _____________.
    Aromotic amino acid decarboxylase (same enzyme used in synthesis of DA and NE)
  54. ____________ is involved in food addiction/obesity because foods high in carbohydrates/sugar contain its precursor ___________. Consumption these types of foods causes a surge in __________ which has calming and antidepressant effects.
    Serotonin; tryptophan; serotonin
  55. Dietary tryptophan has to compete with ___________________ when it attempts to cross the blood brain barrier.
    Large neutral amino acids
  56. ____ is the somatodendritic serotonin autoreceptor and when stimulated it will ______; ___ & ___ are the terminal/synaptic autoreceptors and when stimulated they will ___________.
    5-HT1A; slow the firing rate of the cell; 5-HT1B; 5-HT1D; inhibit further release of serotonin
  57. Serotonergic cell bodies are located in the ___________ and the firing rate of the neurons in this area is important for the regulation of the _______________.
    Ralphae nucleus; sleep/wake cycles
  58. Serotonergic activity facilitates ______________ while inhibiting ____________.
    Output of motor systems; sensory processing
  59. T/F Serotonergic cells bodies have the highest firing rate during sleep
  60. There are __ subtypes of serotonergic receptors most of which are ______________.
    15; metabotropic
  61. 5-HT1A receptors are concentrated in the _______, ________, and _________. These receptors are involved in the ___________, __________, and _____________.
    Hippocampus; amygdala; forebrain; regulation of eating; anxiety; temperature regulation
  62. _____ serotonergic receptors inhibit cAMP causing neuron _____________ and a subsequent decrease in firing rate.
    5-HT1A; hyperpolarization
  63. 5-HT2A serotonergic receptors are concentrated in the _______, _________, and __________. These receptors are involved in __________.
    Cerebral cortex; striatum; nucleus accumbens; halluncinations (LSD/mushrooms)
  64. Ecstasy (MDMA) _______________ of serotonin.
    Blocks reuptake