Opioids and overdose
What natural opioids does the pituitary gland produce?
Endorphins
What does the addictive substance in tobacco bind to?
Nicotinic acetylcholine receptors
Which inhibitory neurotransmitter system does ethanol enhance?
GABA
What chemical in marijuana causes altered perception and distortion of time?
THC (Tetrahydrocannabinol)
Name one commonly abused prescribed stimulant.
Adderall or Ritalin.
How does naloxone reverse opioid overdose?
It blocks opioid receptors
How quickly does nicotine reach the brain after smoking?
About 10 seconds
What two receptor systems does ethanol block, impairing memory and mood?
NMDA-type glutamate receptors and certain GABA-related systems.
What brain area explains short-term memory issues after marijuana use?
The hippocampus
What neurotransmitter is heavily flooded by stimulants to produce reward?
Dopamine.
Why does heroin produce such a fast rush of euphoria when injected?
It reaches the brain in 15–20 seconds and is converted to morphine, which activates opioid receptors and floods dopamine.
Does nicotine itself cause cancer? Why or why not?
No, the carcinogens in smoke (70 of them), not nicotine, cause DNA damage.
What brain structure is damaged in alcohol use disorder, causing tremors and poor coordination?
The cerebellum.
What is anandamide?
The brain’s natural THC-like neurotransmitter (it binds to the same receptors as THC in cannabis). It is present at very low levels and has a very short half-life and is associated with the feeling of reward.
Why is methamphetamine particularly damaging to the brain?
It generates free radicals that destroy dopamine neurons.
Name one medication used to treat opioid addiction and explain how it works.
Methadone or buprenorphine — they stimulate opioid receptors enough to reduce withdrawal and cravings but produce only a limited high.
What is varenicline and why is it effective?
A nicotine mimicking drug that binds α4β2 nicotinic receptors to reduce cravings and block nicotine’s rewarding effects.
Why can ethanol cross the blood brain barrier? What does that mean for blood alcohol levels?
Bonus: Acetaldehyde is the toxic byproduct formed when the liver begins breaking down alcohol. Why do we test blood alcohol levels and not acetaldehyde levels? (hint: think of the BBB)
Ethanol is lipophilic (lipid-soluble) and small so it can slip through the BBB easily.
Because ethanol crosses the BBB so easily, the concentration in the brain matches the concentration in the blood almost immediately.
Acetaldehyde is larger and less lipid-soluble–so it is broken down before it can cross into the brain (meaning although acetaldehyde can be found in the brain it isn’t used to test alcohol impairment levels)
Name one potential medical use of CBD.
Treating seizures, pain, inflammation, or possibly mental illness.
What long-term effect comes from chronic MDMA use?
Damage to serotonin circuits affecting memory and pleasure.
Explain how naloxone’s mechanism differs fundamentally from methadone/buprenorphine, and why naloxone’s effects are short-lived compared to these treatments.
Naloxone is a pure antagonist that blocks opioid receptors without activating them, reversing overdose but clearing rapidly.
Methadone/buprenorphine are partial or full agonists, activating receptors for longer periods and reducing withdrawal. Their slower metabolism gives them longer, more stable effects.
Explain how nicotine raises cardiovascular risk even though it isn’t carcinogenic.
Nicotine stimulates adrenaline release, increasing heart rate, blood pressure, and vasoconstriction, which promotes vascular stress, clotting risk, and stroke/heart disease.
Explain how ethanol affects three different neurotransmitter systems and how each contributes to a distinct symptom of intoxication.
Enhances GABA → anxiety reduction, slowed reaction time
Blocks NMDA glutamate receptors → impaired memory, mood changes
Activates natural opioid circuits → feel-good effects.
Explain why teens are more vulnerable to the long-term cognitive and addiction-related effects of THC.
Adolescent brains are still pruning/stabilizing reward and memory circuits. THC disrupts these developmental pathways, altering dopamine reward signaling and hippocampal plasticity, which increases susceptibility to future addiction and cognitive impairment.
Describe one emerging treatment target for stimulant addiction and explain why it may be promising.
Microglia targeting — since meth causes neuroinflammation, modulating microglia may reduce cravings and neural damage
Oxytocin targeting— enhances social bonding circuits that may counteract stimulant-induced reward dysregulation.