PSYC 455 Lecture Notes - Lecture 20: Neuropeptide, Opioid, Spinal Cord
26 Apr 2018
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PSYC 455
Lecture 20 – Neuropeptides
• Neuropeptides (Small Proteins)
1. Facts:
a. Around 100 types
b. 2 to 40 amino acids long
c. Receptor are always GPCRs
d. Very potent and long lasting:
- Released in very small quantities/sub-nanomolar (i.e. makes them hard to
study)
- Because so long lasting, they can also act as hormones (e.g., CRH)
2. Synthesis:
a. Synthesized in the neuron at the ribosomes and then stored in large dense-core
vesicles:
- Sometimes what you see translated is a prohormone polypeptide (i.e. long
chain which is then snipped into smaller parts)
3. Release:
a. Released from neurons (i.e. similar to neurotransmitters; transported to the
terminal after synthesis):
- Usually only released during increased firing:
i. Dale’s Principle (i.e. once neuron releases one neurotransmitter) goes
out the window because all the classical neurotransmitters can also
release peptides
• Opioid (Endorphins) System
1. Important system for managing pain and euphoria (e.g., runners high):
a. Involved in the CNS and PNS (recall the new shoes on a date story):
- A lot are found in the:
i. Spinal cord (i.e. important for blunting pain signals)
ii. Brain (i.e. important for ignoring pain)
2. Opioid Drug vs. Opiate Drug:
a. Opioid:
- Any drug that acts on opioid receptors
b. Opiate:
- Initial name for drugs derived from the opium plant (e.g., opium and heroin)
- Opiates are under the umbrella of opioid
3. Opioid receptors (all GCPRs):
a. (mu) receptor (MOR):
- Most important for managing pain and euphoria
b. (delta) receptor (DOR)
c. (kappa) receptor (KOR)
• Neuropeptide Classes/Families
1. Neuropeptide Transmitters that act on the Opioid System:
a. Enkephalins:
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 20 neuropeptides: neuropeptides (small proteins, facts, around 100 types, 2 to 40 amino acids long, receptor are always gpcrs, very potent and long lasting: Released in very small quantities/sub-nanomolar (i. e. makes them hard to study) Because so long lasting, they can also act as hormones (e. g. , crh: synthesis, synthesized in the neuron at the ribosomes and then stored in large dense-core vesicles: Sometimes what you see translated is a prohormone polypeptide (i. e. long chain which is then snipped into smaller parts: release, released from neurons (i. e. similar to neurotransmitters; transported to the terminal after synthesis): Spinal cord (i. e. important for blunting pain signals) Brain (i. e. important for ignoring pain: opioid drug vs. opiate drug, opioid: Any drug that acts on opioid receptors: opiate: Initial name for drugs derived from the opium plant (e. g. , opium and heroin) Opiates are under the umbrella of opioid: opioid receptors (all gcprs), (mu) receptor (mor):
