Neuropharm III Flashcards Preview

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Flashcards in Neuropharm III Deck (8)
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1
Q

How are neuroactive peptides inactivated? Where are they frequently seen physiologically?

A

by extracellular peptidases

often in gut and endocrine tissues

2
Q

What are locations with the greatest diversity of neuroactive peptides? (top three)

A

hypothalamus

  1. amygdala
  2. autonomic nuclei
3
Q

How do neuroactive peptides work (type of receptor, features of receptor)

A

All work through G-protein coupled receptors. often slow but long lasting modulators of synaptic function. These tend to be HIGH AFFINITY receptor. All show desensitization in the continued presence of peptides

4
Q

What are the magnocellular hypothalamic neuroactive peptides?

A

oxytocin and vasopressin: released to general circulation

5
Q

What are the other kinds of hypothalamic neuroactive peptides?

A

those released by nuerons that project to the anterior pituitary via the portal circ., and those that project diffusely to autonomic and limbic areas of the brain

6
Q

What peptides modulate pain in the brain?

A

substance P and calcitonin gene-related peptide (CGRP)

7
Q

What peptides modulate central analgesia?

A

opioid peptides (enkephalins beta endorphin, dynorphin) in spinal cord

8
Q

Describe the low-threshold spike

A

after an AP, hyperpolarization occurs.
in some cells, there are T-type voltage gated Ca channels.
These channels open during hyperpolarization.
Ca enters the cell and the cell depolairzes. This gives rise to an Na spike with prolonged Ca-induced depolarization. This is because Ca T channels stay open longer than Na channels.
Important for arousal and sleep regulation, but may be a problem in epilepsy.