Drug use, drug addiction, and the brain's reward circuits Flashcards
Define tolerance
We build tolerance to a drug over time and we need more amounts of the drug to elicit the same effect
Define sensitisation
After prolonged exposure to a drug, and we need less of it to elicit the same effect
Define withdrawal
Physiological reaction to a drug you are dependent on
What is conditioned drug tolerance
Maximal tolerance effects are seen in the environment in which a drug is usually taken
What is contingent drug tolerance
Tolerance only develops to drug effects that are experienced
What are the four different routes of drug administration?
Ingestion (oral), injection, inhalation, absorption through mucous membranes
Describe ingestion as a route of drug administration
Easy and relatively safe, however absorption via digestive tract is unpredictable
Describe injection as a route of drug administration
Bypasses the digestive tract, can be injected under the skin, into large muscles, or into veins and the drug will be delivered directly to the brain
Describe inhalation as a route of drug administration
Absorbed through capillaries in lungs
Describe absorption through mucous membranes
Through the nose nd mouth
How do drugs work?
Usually something to do with synaptic transmission - nicotine binds to nicotinic acetylcholine receptors
What drugs increase dopamine?
Cocaine and amphetamine. They bind directly to the dopamine transporters and increase dopamine in the synapse.
How is MDMA linked to serotonin synapses?
MDMA blocks reuptake and also reverses the reuptake transporter so there is lots of serotonin in the synapse
How does LSD work?
Binds to the serotonin receptors and interferes with sleep waking systems
What receptors does caffeine bind to?
Adenosine receptors. These are postsynaptic to dopamine
