Learning Objectives

Know the 2 most common neurotransmitter classes and the enzymes that degrade them
- I - Acetylcholine (ACh)
  - degraded by Acethylcholinesterase (AChase)
- II- Biogenic Amines: Histamine, Dopamine, Epinephrine, Norepindephrine (NE), serotonin
  - degraded by monoamine oxidase (MAO)
Know what MAOI's and SSRI's do
- MAOIs inhibit MAO - therefore increase all amines (Histamine, Dopamine, Epinephrine, Norepindephrine (NE), serotonin)
- SSRIs inhibit serotonin reuptake - therefore increase serotonin
Know the different Synapse Types, what makes them that way, and consequences
- Electric (aka GAP junction)
  - because the pre-synaptic axon termini is connected to post-synaptic dendrite
  - APs directly from from 1 neuron to the next
  - NO EPSP step
  - Makes much faster
  - if an AP occurs in pre-synaptic neuron it MUST occur in post-synaptic neuron (or cell)
- Chemical Direct
  - standard: Neurotransmitter (Chemical) binds to the receptor channel directly
- Chemical Indirect (aka GPCR)
  - Neurotransmitter binds to a receptor which is a separate protein from the channel
  - Many more steps = Slower
  - Enzymatic Step = Sensitivity Step = Amplification Step
  - 2nd messenger is the actual molecule that opens channel
  - 2nd messenger can have other cell responses (ex: alter gene expression)
  - Final result is STILL an EPSP or IPSP
  - blocking any step (typically) still blocks EPSP

Neurotransmitter Classes

Synapse Types

Systems (animal diversity) & the nervous circuit