Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 331Bi 1 Lecture 13 Monday, April 24, 2005 revised 4/27Recreational drugsNNNNOOH3CCH3CH3caffeine2Disclaimer1. Do not alter your pattern of prescription drug compliance as a result of this course.2. Consult a medical professional for further guidance about prescription drugs. H. A. L. is not aware of all trends in current medical practice, is not a physician, and cannot prescribe.3NH2CH3amphetamineNN CH3CNC2H5C2H5OLSDH3CH2COHethanolNCH3NnicotineNOHOHOCH3morphineNphencyclidineOH3CH3CCH3OHC5H11tetrahydrocannabinolNOCOCOCH3OH3CcocaineNNNNOOH3CCH3CH3caffeine4Coca Harvest in Bolivia, ca. 19505cocaine in the test tubeH+NOCOCOCH3OH3Ccocaine base:directly extracted from the plantwith organic solventstreatment with HCl+HNOCOCOCH3OH3CCl-cocaine hydrochloride:a salt, readily solubletreatment with base:ammonia or Na bicarbonate,then heat to drive off HCl“crack” cocaine6H+bloodlungs,nose,stomachNOCOCOCH3OH3C+HNOCOCOCH3OH3CH+NOCOCOCH3OH3C+HNOCOCOCH3OH3Ccocaine base(crack)cocaine in the bodycocaine hydrochlorideCl-South American Indians use Ca(OH)2 from limestone to shift this equilibriumLipid barrier,e. g. membrane(s)7neurotransmittertransporters ligand-activatedchannelsGPCRsG protein-activatedchannelsNCLSD morphine-herointetrahydrocannabinol amphetamine(*)cocainephencyclidine nicotine?alcohol?caffeine*(*= intracellular target)enzymesTargets for Recreational Drugs8 Na+-coupled cell membrane neurotransmitter transporters:Antidepressants (“SSRIs” = serotonin-selectivereuptake inhibitors):Prozac, Zoloft, Paxil, Celexa, LuvoxDrugs of abuse: MDMAAttention-deficit disorder medications:Ritalin, Dexedrine, AdderallDrugs of abuse: cocaine amphetamineNa+-coupledcell membrane serotonintransporter Na+-coupledcell membrane dopamine transporter NHHO NH3+HOHOH2CCH2NH3+cytosoloutsidemajor targets for drugs of therapy and abusePresynapticterminalsFrom Lecture 5Trademarks:9enzyme inhibitorsneurotransmitter transport inhibitors11Endogenous ligandmorphine-heroin agonist endorphins (peptides)THC agonist anandamidenicotine agonist acetylcholinecocaine antagonist dopamineamphetamine“false substrate”,antagonistnoradrenaline, serotonin, dopamineethanol agonist ?G protein?LSD agonist serotonincaffeine inhibitor cyclic AMP (intracellular)phencyclidine antagonist glutamate12Primary Target Details (dates: )morphine-heroinGPCR (G protein-coupled receptor) (Gi)-opioid receptor 1985-1993THC GPCR (Gi) cannabinoid receptor 1988nicotine agonist-activated channel42 nicotinic acetylcholine receptor 1905-1995cocainecell membrane neurotransmitter transporterdopamine transporter 1980-1991amphetaminevesicular & cell membrane neurotransmitter transportervesicular monoamine transporter 1990 - 1995ethanol ? K channel ?G protein-gated inward rectifier GIRK1/2 1993 - 1999LSD GPCR (Gq) 5-HT2a receptor 1985-1990caffeine enzymecyclic AMP phosphodiesterase 1965phencyclidine ligand-activated channelNMDA glutamate receptor 196513Knockout mice and one application for themGene (DNA)Hypothesis: the response to a drug requires your favorite moleculeInterrupt the gene with a detectable protein(knock out the gene)EGFPReplace the mouse gene with the altered gene Select the mouse with the altered gene Breed many identical micemeasure drug responsevs14Knockout mice in Drugs and the Brain(Behavioral observations) 1. The -opioid receptor-opioid receptor KOs specifically lack responses to certain types of pain (next slide).2. The 42 nicotinic receptor4 or 2 nicotinic receptor knockouts: (1) respond less to nicotine in pain tests (next slide)(2) fail to self-administer nicotine (next slide).3. The dopamine transporterDopamine transporter knockout mice: (1) are hyperactive, (2) show less response to cocaine, (3) self-administer cocaine less4. Cannabinoid receptorsCannabinoid receptor knockouts have little overt differences to normal mice. They don’t show these effects of THC and anandamide: (1) decreased pain responses and (2) decreased heart rate. ---------------------------------------------------5. But NMDA receptor knockouts die at birth: an uninformative result15Two behavioral tests often used on knockout micePain: Mice are placed on a hotplate at 55o C. The experimenter notes the time to lick paws, jump, etc. The experiment terminates at 30 s, regardless of the outcome. A pain-relieving drug increases the time to reactNo permanent harm to the mouse . . . Carefully regulated:http://www.olar.caltech.edu/iacuc-sops.htmSelf-administration of a drug16Source (species: )morphine-heroinPapaver somniferumtetrahydrocannabinolCannabis sativanicotineNicotiana tabacum cocaineErythroxylum cocaamphetaminesynthetic ethanolSaccharomyces cerevisiae (fermentation)LSDsyntheticcaffeineCoffea sp.,Camellia sinensisphencyclidine synthetic“poppy that brings sleep”(opium) marijuana, hemptobaccococacoffeeteayeastergotwheat fungus;Salem witch trials?Based on plant17Gordon A. Alles noted the properties of Ephedra vulgaris, used against asthma. He synthesized amphetamine (Benzedrine).Caltech BS, 1922; MS, 1924; PhD, 1926. Research Associate in Biology, 1939-196318NeurotransmitterandATP(1,000 to 10,000 molecules of each)proton-coupled neurotransmitter pump cytosolATP-driven proton pump pH effects also account for some drug actions on synaptic vesiclesHNCH3OH2COCH33,4-methylenedioxymethamphetamine(“ecstasy”, XTC) pKa ~ 8.5from Lecture 919proton-coupledvesicular serotonin transporter cytosolATP-driven proton pump synaptic cleftNa+-coupledcell membrane serotonin transporterMDMAserotonin vesicleMDMAMDMA-H+H+MDMA (“ecstasy”) or amphetamine itselfdissipate the vesicle’s H+ store, preventing the vesicle from pumping serotoninserotonin depletedserotonin vesicleMDMA-H+Weak acids and weak bases short-circuit many vesicles!from Lecture 9“false substrate”for two transporters20HOHOH2CCH2NH3+The adjacent hydroxyl groups of dopamine are readily oxidized(may partially cause the degeneration of dopaminergic neurons in Parkinson’s disease)A 20th-Century batteryfrom Chem 1 textbook (OGN)Figure 12-06. . . but we can use the fact to detect dopamine in real time in the brain:21 A modified patch clamp circuit and pipette allow us to detect