PS268 Chapter Notes - Chapter 4: Endorphins, Cerebral Cortex, Locus Coeruleus
Drugs and the Brain
-a drug is carried to the brain by the blood supply and once it gets there it goes everywhere
-ex: bc molecules of LSD have effect by acting on serotonin systems, LSD affects the brain
systems the depend on serotonin
-LSD acts on serotonin receptors in in the cerebral cortex and the locus ceruleus
-equilibrium in brain develops quick; drug's concetration in brain is equal to that in the
blood, and number of molecules leaving blood is equal to the number leaving brain to enter
blood
-as drug is removed from the blood and concentration in blood decreases, more molecules
leave brain than enter it, and brain levels begin to decrease
-in most cases, drugs have their effects bc their molecular structure is similar to the structure
of one of the neurotransmitter chemicals
-bc of this similarity, the drug molecules interact w one or more of the stages in the life cycle
of that neurotransmitter chemical
Examples of Drug Actions:
2 types
1) through actions on synthesis, release, storage, reuptake or metabolism, drugs can alter the
availability of the neurotransmitter in the synapse
2) mimicks the action of the neurotransmitter and directly activates the receptors (agonist) or
occupying receptor and preventing neurotransmitter from activating it (antagonist)
Document Summary
A drug is carried to the brain by the blood supply and once it gets there it goes everywhere. Ex: bc molecules of lsd have effect by acting on serotonin systems, lsd affects the brain systems the depend on serotonin. Lsd acts on serotonin receptors in in the cerebral cortex and the locus ceruleus. Equilibrium in brain develops quick; drug"s concetration in brain is equal to that in the blood, and number of molecules leaving blood is equal to the number leaving brain to enter blood. As drug is removed from the blood and concentration in blood decreases, more molecules leave brain than enter it, and brain levels begin to decrease. In most cases, drugs have their effects bc their molecular structure is similar to the structure of one of the neurotransmitter chemicals. Bc of this similarity, the drug molecules interact w one or more of the stages in the life cycle of that neurotransmitter chemical.
