PSYC 280 Lecture Notes - Lecture 2: Caffeine, Lithium Chloride, Catecholamine
4 Apr 2016
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Document Summary
The effects of a drug depend on its site of action and dose. Drugs fit like keys into molecular locks. The various subtypes of receptors differ in their distribution within the brain. Drug molecules do not seek out particular receptor molecules. Drug molecules spread widely throughout the body. When they come in contact with a receptor molecule possessing the correct shape, the two will bind briefly and begin a chain of events. Binding is temporary and when the drug breaks away, the receptor returns to its unbound shape and functioning. The drug can either alter the activity of the receptor by activating or blocking it. Drug receptor interactions vary in specificity and activity. A particular drug molecule will bind strongly to one kind of receptor and more weakly to some other types. A drug molecule that has more than one kind of action in the body exhibits this flexibility.
