Drug and Addiction Flashcards
What happens if there is no reuptake?
You have a lingering effect of that neurotransmitter in the synapse
Depending in the neurotransmitter, this could have various effects
What is a drug?
Chemical or mixture of chemicals that alters physiological functions, structure and behaviour
What are psychoactive drugs?
give rise to feelings of euphoria and altered perceptions
What are the 4 categories of psychoactive drugs?
Depressants
Stimulants
Opiates
Hallucinogens
What are depressants?
Slow activity in the central and peripheral NS
What are stimulants?
Speed activity in the central and peripheral NS
What are opiates?
Powerful painkillers that also provide feelings of extreme well-being , pleasure and calm
What are hallucinogens?
Alter perceptions to the point of creating hallucinations
What is euphoria?
An enhanced sense of pleasure, excitement and well-being
What are antagonists?
Drugs that bind to the same receptors as naturally occuring brain chemicals to block their action
What are agonists?
Drugs that bind to receptors to mimic the effects of the neurotransmitters that naturally bind to it
What are inverse agonists?
Drugs that bind to neurotransmitter receptors but have the opposite effect of the neurotransmitter
What are reuptake inhibitors?
Drugs that inhibit the reuptake of a neurotransmitter by the neuron that released it
What is drug abuse?
Use of drugs in ways that cause physical and/or physiological harm to themselves or to others who are affected by their behaviour
What is drug tolerance?
the phenomenon by which a person needs to take increasingly large amounts of a drug to have the same effect
What are the 3 types of tolerance?
Dispositional, behavioural, and functional
What is dispositional tolerance?
Occurs when the body becomes progressively better at breaking down and eliminating a drug
What is behavioural tolerance?
Occurs when a person has learned to compensate for drug effects
What is functional tolerance?
When neurons become progressively adjusted to the effects of a drug (also known as the cell-adaptation theory)
What are withdrawal symptoms?
Occurs with the cessation of drug use once the nervous system has adjusted to the drug’s presence, may include nausea, headaches, weakness and anxiety
What is the 1st phase of the circuit of addiction?
Positive reinforcement: pleasureable outcomes makes it more likely that the activity will be repeated (getting high on the drug)
What is the 2nd phase of the circuit of addiction?
Negative reinforcement: Withdrawal effect, when a behaviour removes unwanted outcome, it increases the probability to be repeated
What is the 3rd stage of the circuit of addiction?
Preoccupation: constant state of seeking for drug and intense cravings
What is the insensive salience theory?
Theory that suggests that “wanting” and “liking” are at the core of drug addiction instead of the activation of dopamine pathways
What is “wanting”?
Drug-seeking behaviours and strong cravings in addicted people when they are exposed to environmental cues signaling drug consumption
Associated with the mesocorticolimbic dopamine system
What is “liking”?
Pleasureable sensations experienced when taking the drug
Associated with “hedonic hotspots” in the brain
What is the relationship between “wanting” and “linking”?
As wanting grows, liking decreases
What is the conditioned place-preference (CDP) paradigm?
Animal injected with saline in one room and with drug in another, then given the choice of rooms; will prefer the drug room over the saline room
What is the self-administration paradigm?
Animals are taught how to administer themselves a drug
What kind of drug is nicotine? How does it act on the brain?
It is a stimulant
Binds to nicotinic receptors for acetylcholine - exist on dopamine receptors part of the reward circuit; therefore activating the circuit
What kind of drug is alcohol? What is another name given to it?
It is a depressant, also called sedative hypnotic
How does alcohol work in the brain?
Binds to its own receptor on CI- channels which increase the release of GABA (inhibitory) and blocks GABA on dopamine neurons (producing euphoria)
Name other drugs that mimic the effect of alcohol on the brain (which are called hypnotics)
Benzodiazepines (treat anxiety), Non-Benzodiazepines (sleep medications), barbiturates (insomnia)
What are the effects (overall) of marijuana
both depressant and excitatory effects, and hallucinogenic effects in high doses
How does marijuana binds to receptors?
Binds to CB1 (cannabinoids receptors) and inhibit GABAergic neurons through retrograde signaling
(because it stops the inhibitory effects of GABA on dopamine receptors)
What are opioids?
Any drug that binds with opiate receptors
opium, morphine, codeine, heroin
What are the effects of opioids?
Inhibit GABAergic neurons thus increasing rewarding effects of dopamine
What kind of drug is cocaine?
Reuptake inhibitor (prevents neurons to take back dopamine, therefore more dopamine is available to bind on post synaptic neurons - making a rewarding effect)
What causes the increase in locomotor activity (speedy effects) observed in cocaine users?
Increased levels of norepinephrine
What is retrograde signaling?
The proces by which the activity of a neuron is regulated by chemical messenger released by its postsynaptic target neuron
