Human Neuropsych Midterm 2

Starting at "psychopharmacology part 1"

What is psychopharmacology?

The study of how drugs affect our nervous system

What is a drug?

Chemical compound that brings a desired change in the body

What are psychoactive drugs?

Drugs that alter mood, thought, or behaviour

What three areas of the brain lack tight junctions?

Pituitary gland, pineal gland, and area postrema

What chemicals does the pituitary gland allow through?

Hypothalamic chemicals that influence hormone secretion

What chemicals does the area postrema allow through?

Toxic substances to induce vomiting

What chemicals does the pineal gland allow through?

Melatonin (into the bloodstream)

How do psychoactive drugs work?

Influencing the steps in synaptic transmission

What do agonists do?

Increase the effectiveness of neurotransmission

What do antagonists do?

Decrease the effectiveness of neurotransmission

Which toxins are ACh agonists?

Black widow spider venom, nicotine, organophosphates, and physostigmine

What toxins are ACh antagonists?

Botulin toxin and curare

What are organophosphates?

ACh agonist that blocks the inactivation of ACh, also known as sarin-nerve gas

What are the three types of tolerance?

Metabolic, cellular, and learned

What is metabolic tolerance the result of?

An increase in enzymes needed to breakdown alcohol

What is cellular tolerance a result of?

An adjustment in neuron activity, minimizing the effects of alcohol

What is learned tolerance a result of?

Learning to cope with daily demands under the influence

What happens to the effects of psychoactive drugs after repeated administration?

They progressively diminish

How do you reverse the effects of tolerance?

Abstaining from the drug to recalibrate your nervous system, e.g., abstaining from cannabis for 2 days reverses its tolerance

Why do morphine users seek out Fentanyl?

It is a potent synthetic opioid, many use it once they’ve built up a tolerance to morphine

Why does illegally manufactured fentanyl lead to?

Opioid overdose deaths

Why is fentanyl and other synthetic opioids (carfentanil) considered toxic?

They inhibit neurons that regulate breathing in the brainstem

How can you reverse the inhibition of the neurons in the brainstem?

Administering naloxone (narcan) = an opioid antagonist

What is drug sensitization?

An increased response to an equal (i.e., regular) dose of a drug

Why is drug sensitization long-lasting?

Changes in the Nucleus Accumbens (and other brain regions)

What are two factors that commonly affect how drugs can damage the brain?

Genetic susceptibility and potential contaminants in drugs

What is MPTP?

A drug contaminant that is metabolized into MPP+ (neurotoxin)

What has been found to have a similar effect as MPTP?

Environmental compounds, like pesticides and herbicides

What is MSG?

A molecule that is structurally similar to glutamate, produces neuron death

Can MSG be used safely?

Evidence suggests that it can be safe in food, plus glutamate is found in food

What kind of taste receptors do we have for glutamate?

Umami (savory taste)

What does excessive glutamate lead to?

Influx of calcium, leading to apoptosis (cell death)

What is ibotenic acid?

A glutamate-like chemical that is found in poisonous mushrooms, used as a brain lesioning agent

What is ketamine?

A selective antagonist of the NMDA ionotropic glutamate receptor

What is phencyclidine?

an NMDA receptor agonist

When is there always the danger of contamination with toxic substances?

When drugs are bought on the street

What is MDMA being explored for?

Therapeutic effects, e.g., treating PTSD

What is chronic marijuana use associated with?

Onset of psychosis in teenagers

What can influence drug responses?

Individual differences, learned behaviours, culture and environmental context, and the setting

What is the disinhibition theory of alcohol?

Alcohol can depress learned inhibitions, specifically on the brain region (the cortex) that controls judgment

What is alcohol myopia (nearsightedness)?

People under the influence to focus only on the most obvious/immediate cues around them, and ignore less obvious information and potential consequences

What is the learning theory (of alcohol)?

Behaviour under the influence is both learned and specific to culture, group, and setting

What does the placebo effect show?

how context and learned behaviour can influence drug experience

What is substance abuse?

Relying on a drug chronically and excessively

What are withdrawal symptoms?

Unpleasant and dangerous physical symptoms following a sudden stoppage of a drug

What is the dopamine hypothesis of addiction?

All drugs of abuse eventually act on the dopamine system

What is the incentive-sensitization theory?

Wanting and liking theory: addiction is unconsciously acquired and is the result of conditioned learning

How many stages does addiction occur in, according to the incentive-sensitization theory?

3: activation of pleasure, classical conditioning, and incentive salience

What is the incentive salience stage?

When cues associated with the drug become desired and sought out

What does the incentive-sensitization theory suggest that?

Repeated use of drugs leads to tolerance of the liking (pleasurable) effects, while the wanting (craving) effects remain sensitized

How do drugs influence epigenetics?

They can influence gene regulation: turning off voluntary control genes and turning on genes related to behaviours making one susceptible to addiction

What is a drugs chemical name?

The drugs chemical structure

What is a drugs generic name?

A non-proprietary name

What is a drugs brand name?

The capitalized brand name, proprietary to a pharmaceutical company

What is a drugs street name?

The name used by growers, sellers, and users

What type of sedative-hypnotics and anti-anxiety agents are used to cope with major life stresses?

Benzodiazepines

What is tolerance?

With repeated use, a larger dose is required to get the same effect

What is cross-tolerance?

When the tolerance from one drug carries over to a different member of the same drug group

What does cross-tolerance suggest that?

Anti-anxiety and sedative-hypnotic drugs act on the NS in similar ways

How do all sedative-hypnotics work?

Influencing GABA_A receptors

What do alcohol and barbiturates do after binding to the sedative-hypnotic sites (on the receptors)?

Increase the influx of calcium (Cl^-)

What do benzodiazepines do once they bind to the anti-anxiety sites (on receptors)?

Maximize the time the pore is open

What is picrotoxin?

A drug that blocks GABA_A’s ion pore and produces overexcitation and epileptic discharges

Why are sedative-hypnotics and anti-anxiety drugs used to treat epilepsy?

They enhance the action of GABA_A receptors

What are dissociative anesthetics?

Drugs that have sedative-hypnotic and anti-anxiety effects: PCP (phencyclidine), ketamine, and GHB (gamma-hydroxybutyrate)

Why do ketamine and GHB (date rape drugs) impair memory for recent events?

They are soluble in alcohol, so they act quickly

Why is ketamine used as a safe anesthetic?

It does not depress breathing

What has ketamine been recently used to treat?

Depression

What type of drug is ketamine?

A selective antagonist for the NMDA ionotropic glutamate receptor

What is the “K-hole”?

Where users enter a dissociative state due to ketamine

What is psychosis characterized by?

Hallucinations (false perceptions) and delusions (false beliefs)

What is the dopamine hypothesis of schizophrenia?

Main schizophrenic symptoms are related to an excess of dopamine

What is chlorpromazine?

First generation antipsychotic, blocks D₂ receptors

How does vitamin D contribute to depression?

A Vitamin D deficiency is one of the causes of depression, obtained through fish/exposure to sun

How do antidepressants act on the nervous system?

Improving chemical neurotransmission at serotonin synapses

Why can some SSRI effects take weeks to develop?

They are activating second messenger cascades, which then have their own effects

What are mood stabilizers (e.g., salt lithium carbonate) used to treat?

Bipolar Disorder

What is mescaline?

A serotonin agonist: effects 5-HT due to causing cross-tolerance with serotonin psychedelics

What type of drug is MDMA/ectasy?

An indirect serotonergic agonist

What are examples of serotonin psychedelics?

LSD (acid), psilocybin, ayahuasca

What is a nootropic effect?

Leads to cognitive enhancement

How are serotonin psychedelics being used as a means for nootropic effects?

Microdosing

What are the main groups of psychedelics and hallucinogens?

Serotonin psychedelics, Acetylcholine stimulants, Glutamate psychedelics, Tetrahydrocannabinol (THC)