Neurotransmitters

Question 0

Effects of Norepinephrine

Answer 0

• autonomic
• Catecholamine w/ multiple functions as a hormone and NT
• Released from sympathetic neurons-increases HR etc

Question 1

Functions of Acetylcholine

Answer 1

• autonomic, somatic
• NT in CNS and PNS
• PNS: activates muscles
  
  • a major NT in the autonomic nervous system.
• CNS: Part of cholinergic system- anti-excitatory actions.

Question 2

Effects of Epinephrine

Answer 2

• autonomic
• regulates HR, blood vessel & air passage diameters, and metabolic shifts
• Fight or flight in sympathetic NS

Question 3

Effects of Histamine

Answer 3

• autonomic and CNS
• involved in local immune responses
• regulates physiological function in the gut
• acts as NT

Question 4

Effects of GABA

Answer 4

• CNS

- Main inhibitory NT

Question 5

Effects of Dopamine

Answer 5

• CNS
• roles in behavior and cognition,
• voluntary movement
• motivation, punishment and reward
• inhibition of prolactin production
• sleep, dreaming, mood
• attention, working memory, and learning

Question 6

Effects of Serotonin

Answer 6

CNS

Question 7

metabolism of phenylalanine

Answer 7

• Phenylalanine converted to Tyrosine
• Mediated by Phenylalanine Hydroxylase
• In the process, O2 converted to H2O
• Reaction requires tetrahydrobiopterin
  
  • BH4 converted to BH2
• important in the synthesis of catecholamines
  
  • Tyrosine converted to Dopa then to dopamine
  • dopamine converted to norepinephrine
  • Norepinephrine converted to epinephrine

Question 8

signs and symptoms of phenylketonuria (PKU)

Answer 8

• PKU results from defect in phenylalanine hydroxlase
• Variant form: defective enzyme in tetrahydrobiopterin synthesis
• Therefore, Phenylalanine is not converted to tyrosine
• Phenylalanine accumulates & converted to compounds such as phenylketones
• Mental retardation occurs
• Treat w/ restriction of phenylalanine in diet

Question 9

Common Reactions in NT Metabolism

Answer 9

• Examples of Most Common Methylation Reactions
  
  • RNH3 + SAM –> RNH2-CH3 + SAH
  • ROH + SAM –> ROCH3 + SAH
  • (SAH = S-Adenosylhomocysteine, SAM minus methyl group)
• Hydroxylase Reactions: addition of -OH
  
  • Tetrahydrobiopterin reaction
  • BH4–>BH2
  • Adds OH group
• Decarboxylation

Question 10

vitamins and cofactors involved in neurotransmitter metabolism

Answer 10

• Pyridoxal phosphate (PLP)
  
  • The quintessential coenzyme
  • Carries out >10 types of reactions (see next slide)
  • Is everywhere in AA pathways
• Tetrahydrobiopterin (BH4)
  
  • Catalyzes ring hydroxylations
• S-Adenosylmethionine (SAM)
  
  • Methylating agent