Intro to CNS Pharmacology Flashcards Preview

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Flashcards in Intro to CNS Pharmacology Deck (16):

What is the RMP in neurons?

- 60 mV


Nernst Potentials for K, Na, Cl

K = -75mV
Na = +55mV
Cl = -69mV


What are the two types of synaptic potentials and what do they do?

EPSP: mem potential moves to more + values
IPSP: men potential moves to more - values


Two mechanisms by which an EPSP can occur

1. Increased conductance: open ligand gated K or Na channels
2. Decreased conductance: close K leak channel


Three mechanisms for production of IPSPs

1. Increased conductance of mem K or Cl
2. Ligand-gated Cl channel (GABA receptor)
3. GPCR can open K channel: direct interactions or by changes in phosphorylation state of K channels that are closed


What is Norepinephrine synthesized from?



Where are noradrenergic neurons located?

Medulla oblongata, pons and midbrain = reticular activating system --> role in arousal and ANS regulation


What is the rate limiting step/enzyme for Norepi synthesis? And what is a necessary cofactor?

Tyrosine hydroxylase; BH4


Where is Norepi stored?

1. Vesicular; with dopamine B-hydroxylase enzyme
2. Vesicular transporters: VMATs - VMAT2 in brain


How is Norepi released?

1. Ca dependent exocytosis
2. Plasma mem transporters working in reverse
3. Dendritic release: not Ca dependent


What are the two modulating autoreceptors for Norepi release?

1. alpha2 receptor: inhibits release, feedback regulation
2. beta receptor: increases release, feed forward regulation


How can Norepi be inactivated?

1. Diffusion
2. Neuronal reuptake -- SERT, Na symporter
3. 2 catabolic enzymes: MAO, COMT


Receptors for Norepi

All are GPCRs and can also bind epi
1. alpha1: non neuronal cells in periphery, coupled to 2nd messengers that increase Ca
2. alpha2: inhibits adenyl cyclase; often on presynaptic neurons; release-inhibiting auto receptor
3. beta: increases adenylyl cyclase activity


Where is neurotensin located? What other ntm is it co-localized with?

Prefrontal cortex, hypothalamus and midbrain; always co-localized with dopamine


How is neurotensin synthesized?

170 aa precursor --> hydrophobic signal sequence directs the protein to the ER --> packaged into secretory vesicles in the golgi (peptidases) --> processed by peptidases into neurotensin and neuromedin N


How is neurotensin inactivated?

1. Non-selective peptidases
2. Diffusion
NO reuptake but receptor can be internalized with the peptide