2017-02-15 08:39:37

Today's Topics

  • Wrap-up on neurotransmitters
  • Quiz 2 on Friday.
  • Review Exam 1 on Friday.

Black widow spider venom causes paralysis by impeding the normal function of which neurotransmitter system?

  • Glutamate (Glu)
  • GABA (GABA)
  • Dopamine (DA)
  • Acetylcholine (ACh)

Black widow spider venom causes paralysis by impeding the normal function of which neurotransmitter system?

  • Glutamate (Glu)
  • GABA (GABA)
  • Dopamine (DA)
  • Acetylcholine (ACh)

With one exception, the monoamine neurotransmitters bind to what type of receptors?

  • ionotropic
  • voltage-gated
  • nicotinic
  • metabotropic

With one exception, the monoamine neurotransmitters bind to what type of receptors?

  • ionotropic
  • voltage-gated
  • nicotinic
  • metabotropic

With one exception, the monoamine neurotransmitters bind to what type of receptors?

  • ionotropic
  • voltage-gated voltage gated Na+, K+, and Ca++
  • nicotinic ACh binds to nAChR; ACh not a monoamine
  • metabotropic

The outward flow of this ion across the neural membrane creates what kind of PSP?

  • Cl-; IPSP
  • K+; IPSP
  • Glutamate; EPSP
  • GABA; EPSP

The outward flow of this ion across the neural membrane creates what kind of PSP?

  • Cl-; IPSP
  • K+; IPSP
  • Glutamate; EPSP
  • GABA; EPSP

The outward flow of this ion across the neural membrane creates what kind of PSP?

  • Cl-; IPSP Outward Cl- -> inside less negative = EPSP
  • K+; IPSP Make inside less positive
  • Glutamate; EPSP Glu not an ion; transported across
  • GABA; EPSP GABA not an ion; transported across

Serotonin (5-HT)

  • Released by raphe nuclei in brainstem
  • Role in mood, sleep, eating, pain, nausea, cognition, memory
  • Modulates release of other NTs
  • Most of body's 5-HT regulates digestion

5-HT anatomy

5-HT receptors

  • Seven families (5-HT 1-7) with 14 types
  • All but one metabotropic

5-HT clinical significance

  • Ecstasy (MDMA) disturbs serotonin
  • So does LSD
  • Fluoxetine (Prozac)
    • Selective Serotonin Reuptake Inhibitor (SSRI)
    • Inhibits reuptake -> increases extracellular concentration
    • Treats depression, panic, eating disorders, others
  • 5-HT3 receptor antagonists are anti-mimetics used in treating nausea

Melatonin

  • Released by pineal gland into bloodstream

Pineal gland

Histamine

  • In brain, released by hypothalamus, projects to whole brain
    • Metabotropic receptors
    • Role in arousal/sleep regulation
  • In body, part of immune response

Other NTs

  • Gases
    • Nitric Oxide (NO), carbon monoxide (CO)
  • Neuropeptides
    • Substance P and endorphins (endogenous morphine-like compounds) have role in pain
    • Orexin/hypocretin, project from lateral hypothalamus across brain, regulate appetite, arousal

Other NTs

  • Neuropeptides (continued)
    • Cholecystokinin (CCK) stimulates digestion
    • Oxytocin and vasopressin released by posterior hypothalamus onto posterior pituitary, regulate social behavior

Non-chemical communication between neurons

  • Gap junctions
  • Electrical coupling
  • Connect cytoplasm directly
  • Fast, but fixed, hard to modulate
  • Examples, retina, cardiac muscle

Gap junctions

Ways to think about synaptic communication

  • Specificity: point-to-point vs. broadcast
  • Direct vs. modulatory
  • Agonists vs. antagonists

Agonists vs. Antagonists

  • Agonists
    • bind to receptor
    • mimic action of endogenous chemical
  • Antagonists
    • bind to receptor
    • block/impede action of endogenous chemical

Valium is a GABA-A receptor agonist. This means:

  1. It decreases inhibition
  2. It activates a metabotropic Cl- channel
  3. It facilitates/increases inhibition
  4. It blocks an ionotropic channel

Valium is a GABA-A receptor agonist. This means:

  1. It decreases inhibition
  2. It activates a metabotropic Cl- channel
  3. It facilitates/increases inhibition
  4. It blocks an ionotropic channel

Next time…

  • Quiz 2
  • Go over Exam 1

References