3.3 Control feeding, sexual behavior, and social functions. Flashcards
define Agonist
Mimics or potentiates the action of a neurotransmitter by activating its receptors.
Antagonist:
Reduces the normal actions of a neurotransmitter by binding to receptors without activating them, effectively blocking them.
Partial Agonist
Produces a middling response by partially activating receptors.
Binding Affinity
The chemical attraction of a drug to a receptor. High-affinity drugs bind strongly to their target receptors.
Efficacy
The ability of a bound drug to activate a receptor.
Agonists have high efficacy.
Antagonists have no efficacy.
Low doses
Drugs bind primarily to high-affinity receptors.
High doses:
Drugs may also bind to lower-affinity receptors.
Smoking or intravenous injection:
Rapid drug bioavailability.
Ingestion:
Slower build-up of drug concentration.
Pharmacokinetics:
Study of how drugs move into, through, and out of the body.
Biotransformation
Metabolism of drugs into active or inactive metabolites.
Drug-Receptor Interactions
Drug molecules spread widely throughout the body.
They bind selectively to receptors, initiating cellular responses.
Binding is temporary; receptors reset once the drug detaches.
Selective Drug Design
Neurotransmitters act on multiple receptor subtypes.
Drugs can be designed to target specific receptor subtypes for desired effects.
Example: Selective serotonin receptor blockers (5-HT3 antagonists) treat nausea without affecting other serotonin receptor subtypes.
Ligand
Any molecule that binds to a receptor.
Includes neurotransmitters and drugs.
Psychoactive Drugs
Affect brain function and conscious experiences.
