Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

28 Cards in this Set

  • Front
  • Back
Define Neuropeptide:
A peptide that functions as a signalling molecule and is released from neurons
How many amino acids are in neuropeptides typically?
2 - 40
How long is Neurotensin?
13 AA
Where is Neurotensin found?
-Prefrontal cortex
What is important to remember about neurotensin's location?
It is always located with dopamine - COLOCALIZED
Is dopamine always found with neurotensin?
No; just the other way around.
Is co-localization unique to neurotensin?
No it is a characteristic of most peptide transmitters.
What is achieved by colocalization?
More refined, specific, and complexity of signals.
What is neurotensin synthesized from?
A 170 aa protein precursor that contains NT + Neuromedin N
Where is Neurotensin's precursor sent?
To the golgi via its hydrophobic signal sequence
What happens to the precursor in the golgi?
Packaging into secretory vesicles along with peptidases.
How is Neurotensin made from its precursor?
By processing via peptidases - they produce 1 Neurotensin + 1 Neuromedin N
Important point to remember about the packaging of Neurotensin:
This is not into Synaptic Vesicles, rather Secretory granules
How are secretory granules containing Neurotensin released?
Via the constitutory pathway
What is the morphologic nature of the neurotensin-containing granules?
They are electron dense - DENSE CORE
How does neurotensin get to the nerve terminal?
By axonal transport
How much neurotensin is usually stored at the axon terminal?
Low amounts - it varies.
How is Neurotensin release from the axon terminal mediated?
Calcium dependent
What is required for Neurotensin release?
Rapid firing of neurons at HIGH INTENSITY
3 Ways that Neurotensin release is different from that of normal neurotransmitters:
-Requires more calcium and higher intensity AP firing
-No vesicles, and the granules are not recycled or refilled
-Exhibits extrasynaptic release beyond Active zone
What is extrasynaptic release?
The ability of a NT to act on more than one postsynaptic neuron
So how do Secretory vesicles filled with Neurotensin differ from normal vesicles? (3 ways)
1. Dense cores on EM
2. 2x Larger
3. Transported to axons via secretory pathways at low and variable concentrations.
3 Ways that Neurotensin inactivation is regulated:
1. Peptide cleavage via extracellular peptidases
2. Diffusion away from synapse
3. Internalization of peptide bound to its receptor
Do neurotensin-releasing nerves exhibit reuptake?
How does neurotensin inactivation compare to that of Glutamate and Norepinephrine?
-Less directed
-Lasts longer
-Lower fidelity
What is the nature of Neurotensin's receptor binding?
High affinity b/c the molecule is so big.
Receptor type for neurotensin
G-protein linked
How is neurotensin activity related to dopamine?
Activation of Dopamine auto-receptors (to inhibit dopamine's presynaptic release) enhance NT release.