Exam 5 (CH. 6) Flashcards
How are NT defined/identified?
- be synthesized & stored in the presynaptic neuron
- be released upon stimulation
- Evoke the same response as observed with stimulation of the presynaptic neuron.
How might one localize NT systems in the brain?
- by immunocytochemistry
- specific for proteins - in situ hybridization:
- mRNA transcripts for proteins
What are the precursors for the main NTs we discussed?
- DA, NE & E : tyrosine
- GABA: glutamate
- 5-HT: Tryptophan
- Ach : Choline
What is the rate-limiting step for each NT’s synthesis?
- Ach: choline
- DA, NE & E: Tyrosine hydroxylase (TH)
- 5-HT: Tryptophan hydroxylase
- GABA: GAD
What kinds of receptors might each NT have (a few examples?)?
Ach: cholinergic (nictotinic & muscarinic receptors) ion gated channels
Glutamate receptors (ligand gated ion channels): NMDA, AMPA, & kainate
What NT system is typically affected by Parkinson’s disease? What is an early treatment for it? Why does this work?
- Dopamine
- giving them dopa
- helping the remaining cells & can start making a little more dopamine. Helps slow progression of the disease
How are NT cleared from the synapse (know which ones are cleared in that way)?
- Dopamine, NE, & E: reuptake by selective transporters; degradation by MAO inside
- Ach: Acetylcholineasterase breaks them down
- 5-HT: reuptake
- GABA: reuptake
What is the structure of a ligand gated ion channel? Think about primary/secondary/teritary structure
What do various receptors do in response to ligands binding (we discussed some examples- in terms of what must happen for the ion channels to open, & what ions they provide passages for)
What are methods used to identify whether NT are involved at synapses?
Divergence: one transmitter activates more than one receptor subtype greater post synaptic response
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