The Effects of Drugs on Neurotransmitters q Agonist

The Effects of Drugs on Neurotransmitters q. Agonist - mimic OR increase Nts’effects q. Antagonist - block the Nts’ effects q. Can facilitate OR inhibit production and release of Nts q. Can alter Nt’s effects after attachment to receptors

Other Examples: q. Cocaine: affects dopamine system • stimulates different dopamine receptors • prevents reuptake of dopamine • long term use upsets normal levels q. Sedatives: activity in the GABA system q. LSD, PCP, Mescaline, Ecstasy (MDMA): affect serotonin production and receptors q. Prozac, Paxil and others: SSRI (Selective Serotonin Reuptake Inhibitor); reduces the reuptake of serotonin (thus more is available)

Example: Alcohol q. Inhibits the flow of sodium across the neuron’s membrane q. Makes some GABA receptors more responsive q. Affects dopamine, serotonin and other neurotransmitter systems q. It becomes even more complex when mixed with sedatives

Example: Amphetamines q the release of norepinephrine (neurotransmitter) q its reuptake (thus more of it is available) q the release of dopamine (neurotransmitter) and blocks its reuptake

http: //www. pbs. org/wnet/closetohome/animation/cocaanim-main. html

http: //prozac. com/how_prozac/how_it_works. jsp? req. Nav. Id=2. 2 http: //www. pbs. org/wnet/closetohome/science/html/whydrugs. html http: //thebrain. mcgill. ca/flash/i/i_03_m/i_03_m_par_alcool. html

Shows pronounced reductions (83 -95%) in serotonin axon density in all areas of the cerebral cortex. The last section shows that seven years after MDMA was given, there is still significant loss of serotonin fibers, though there appears to be some recovery