CNS Neurotransmitters

Question 1

Monoaminergic systems tend to be. . .

Answer 1

. . .more diffuse with multiple inputs to different levels of the CNS
(ex: norepinephrine containing neurons have cell bodies in locus ceoruleus projecting many other places)

Question 2

Motor and sensory perception pathways are typically hierarchical meaning. . .

Answer 2

1. Disruption at any level ablates the system

2. No redundant mechanisms

Question 3

What are the two primary receptor types used by NTs?

Answer 3

1. Ligand gated ion channels

2. Metabotropic receptors

Question 4

Where can drugs act in neurotransmission?

Answer 4

• NT storage
• NT metabolism
• NT release
• NT reuptake
• NT degradation
• NT receptors
• Ion conductance

Question 5

How are hierarchical neuronal systems organized?

Answer 5

• Aligned in order almost linearly

- Examples are sensory perception and motor control

Question 6

How are diffuse neuronal systems organized?

Answer 6

They are not highly ordered and affect numerous regions of the brain via diffusion of NT.
-Ex: monoaminergic containing neurons (norepinephrine, dopamine, Serotonin)

Question 7

What NT usually causes inhibitory postsynaptic potentials?

Answer 7

Glycine

Question 8

What usually causes an EPSP?

Answer 8

Glutamate

Question 9

Where can drugs act?

Answer 9

• Action potential (lidocaine -blocks Na channels)
• Synthesis of NT (DOPA to inc. dopamine)
• Storage of NT (reserpine depletes norepinephrine)
• Metabolism of NT (monamine oxidase inhibitors prevent monoamine metabolism)
• Release of NT (methamphetamine)
• Uptake of NT (Cocaine prevents dopamine uptake in nerve – works at same sites as antidepressants)
• Degradation of NT (Anticholinesterase prevents acetylcholine degradation)
• Receptor interaction with NT (Either agonists or antagonists can be used for a variety of applications
• Ion conductance

Question 10

Describe prednisone

Answer 10

Lipid soluble, diffuses into the cell, transcriptional regulator

Question 11

How long does chemical transmission take?

Answer 11

1/2 second

Question 12

Tell me about Metabotropoic Receptors

Answer 12

• Receptor interacts with a GTP-binding protein
• Modulates voltage gated channels
• –Typically enhances K or inhibits Ca channels
• –Typically inhibitory

Question 13

Tell me about Ligand-gated channels

Answer 13

• Open briefly (tens of milliseconds)
• Account for fast action potentials
• An example is glutamate receptors
• Can either activate or inhibit

Question 14

What are the two types of channels in most neurons?

Answer 14

1. VG
   - Na
   - Ca
2. Ligand-Gated
   - Glutamate, GABA (inhib. Cl- flows through), 5HT - Serotonin
   - ACh