Neuro 342 Drugs and Behavior: Opiates Pt. 1

- opiate are alkaloids extracted from opium poppy,

- opioid is a substances that mimic effects of morphine

What's the difference between opiate and opioid?

from opium plant

- Thebaine, morphine, codeine

where are natural opioids found?

reated from natural opioids — heronin

what are semisynthetic opioids?

created in a lab

- ex: fentanyl and methadone

What are synthetic opioids?

"Skin popping"

In administration of opioids, What is the term for subcutaneous injection of heroin called?

"mainlining"

in administration of opioids, What is the term for IV injection of heronin?

chasing the dragon

What is it called when you smoke heronin?

in the liver

Where are most opioids broken down?

Morphine and Morphine-6-glucuronide(M6G)

- Active metabolites

What is heroin metabolized into?

powerful pain relieving effects

what does M6G produce

M6G and morphine

What is codeine metabolized into?

first order kinetics

How are opioids removed from the body?

~ 7 hours

What is the half life of fentanyl?

~ 2-3 hours

What is the half life of morphine?

~ 1 hour

What is the half life of heroin?

~ 3 hours

What is the half life of codeine?

- Endorphins

- Enkephalins

- Dynorphins

Name the 3 major families of endogenous opioid neuropeptides?

hypothalamus and pituitary gland

Where are endorphins synthesized?

reinforce analgesia and euphoria effects of opioid uses, can cause respiratory depression

What are the effects of endorphins?

throughout CNS and adrenal medulla(PNS)

Where are enkephalins produced?

in the hypothalamus, striatum, hippocampus, and spinal cord

Where are dynorphins produced?

- Pain/stress

- Learning and memory

What are dynorphins involved in?

- Mu receptor

- Delta receptor

- Kappa receptor

What 3 receptors are the effects of opiates mediated by?

Mu

The location of ____ receptors reflect the effects of morphine?

endorphin

Which endogenous peptides of Mu receptors are involved?

- Thalamus

- PAG

- Raphe nuclei

- Spinal cord

Which locations of Mu receptors are involved with the effects of analgesia?

nucleus accumbens

Which location of Mu receptors are involved with the effects of reinforcement?

brainstem

Which location of Mu receptors are involved with the effects of cardiovascular, respiratory depression, nausea, and vomiting?

thalamus and striatum

Which location of Mu receptors are involved with the effects of sensorimotor integration?

endorphin and enkephalin

Which endogenous peptides are involved delta receptors?

- cerebral cortex

- Thalamus

- Striatum

- Spinal cord

Where in the brain are delta receptors found?

- Olfaction

- Motor integration

- Reinforcement

- Cognitive functions

What is the role of delta receptors?

dynorphin

For kappa receptors what is the major peptide?

- Striatum

- Hippocampus

- Amygdala

- Hypothalamus

- Pituitary

Where are kappa receptors found in the brain?

dysphoria, stress, memory

The kappa receptors found in the hippocampus, amygdala, hypothalamus, pituitary are involved in what?

Gut motility and feeding

The kappa receptors found in hypothalamus is involved with what?

local GABA interneurons

What is activity of DA neurons in the VTA controlled by(decrease DA)?

B-endorphin increase VTA firing by inhibiting GABA cells

- Increase DA

How do opioids alter mesolimbic DA?

act on Kappa receptor on DA neuron terminals

- Reduce release of DA —> cause dysphoria

How do dynorphins affect DA?

- Heroin

- Morphin

- Fentanyl

- Oxycodone

What opiates are agonists at the MU receptor?

buprenorphine

What opiates are partial agonists at the MU receptor?

- Narcan

- Naltrexone

What opiates are antagonists at the MU receptor?

- Rush

- High

- Nod

- Straight

List the subjective effects of opioids?

loperamide(Imodium)

What type of opium and morphine is used to treat diarrhea?

Nociceptors

What type of pain receptors detect chemical, mechanical or therm pain?

pain signals to neurons in spinal cord

What happens when Mu opioid receptors found presynaptically on 1st order spinothalamic neurons transmit?

cause IPSP

What happens when binding of piate drugs on postsynaptic Mu opioid receptors on 2nd order spinothalamic neurons?

acupuncture

What is the term for releasing endogenous opioids?