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Bi 1 “Drugs and the Brain” Lecture 1 Monday, March 27, 2006 Organization of the Course 1 The Bi 1 2006 Home Page http://www.its.caltech.edu/~bi1/ 2 Biology 1 at Caltech •In the mid-1990’s, the Caltech faculty instituted a requirement that all students must take biology as part of the “core curriculum” •We have ~220 freshmen •~ 35 Biology majors and other interested Freshmen take a two-course intro to molecular and cellular biology •~ 185 Freshmen take Bi 1 in the Spring •Math, physics, chemistry, and engineering majors •All believe that biology should be derived from first principles 4 Henry Lester’s Goal: provide the principles that will allow Caltech grads to appreciate the progress in clinical neuroscience over the next 5-20 years College freshmen are not interested in disease Challenge: provide a “stealth” introduction to clinical neuroscience, while addressing Caltech students’ interest in quantitative descriptions No illegal drugs, please 5 Biology 1 “Drugs and the Brain” 1. quantitative descriptions 2. single-molecule phenomena 3. lots of Caltech connections How do we progress from biophysics to clinically relevant neuroscience? 6 A 20-minute survey of Bi 1 7 What’s a Drug? nicotine (Nestler Fig. 12-4) procaine (Nestler p. 50) H3CH 2C N morphine (Nestler Fig. 16-3) botulinum toxin (Nestler p. 203, 323) CH 2CH 3 H2C HO CH 2 N CH 3 N O O C O N CH 3 HO morphine NH 2 8 Most drug receptors are membrane proteins. Proteins are beautiful. ~ 100 Å (10 nm) 9 We’ll learn to view and manipulate pictures of molecules http://www.its.caltech.edu/~lester/Bi-1/AChBP-2004-BindingSite.pdb 10 Front Back What is a Brain? 11 Electricity is a language of the nervous system Nestler Figure 3-1B Nestler Figure 3-1B 12 The synapse is a point of information processing presynaptic neuron postsynaptic neuron Nestler Box 2-3 Figure A An adult human brain contains ~ 1011 neurons, and each of these might receive 103 synapses apiece, for a total of 1014 synapses. Most of these synapses form during the first 2 yr of life. Thus 1014synapses/108 s = 106 synapses/s form in a fetus and infant! 13 Principle of the Stereo Tetrode Voltage minus Channel 1 Channel 2 Channel 3 Amp. Channel 3 Amp. Channel 4 Channel 4 Amp. Channel 2 Amp. Channel 1 14 A functional magnetic resonance imaging (fMRI) image. This is the rear view of a human brain activation associated with performance of a task that utilizes motor, visual and planning cognitive processes. The subject was moving a joystick to follow a target around a video display. http://www.cmrr.umn.edu/research/functional.shtml 15 The Central Dogma of Drugs and the Brain, Part 1: Drugs Activate and Block Ion Channels Drug Receptor current time 16 Drug interactions at the nicotinic acetylcholine receptor Some drugs compete with nicotine Some drugs bind on the axis ~ 100 Å (10 nm) 17 n =1 time constant = 1/k21 0 time constant = 1/(k21+ k23) + etc 18 Site-Directed Mutagenesis on Ion Channels DNA Mutate the desired codon(s) RNA polymerase promoter in vitro RNA synthesis measure Express by injecting into immature frog eggs measure 19 Channels are miniature conductors that add in parallel GNa = SgNa GK = SgK outside GNa GK = ENa EK (- 60 mV) gK gNa (+60 mV) inside gNa mostly Na+ mostly K+ gK 20 Little Alberts Panel 1-1 21 The Central Dogma of Drugs and the Brain, Part 2: Drugs Act on G protein pathways How fast? 100 ms to 10 s Neurotransmitter or hormone binds to receptor How far? Probably less 1 mm activates G protein Effector: enzyme or channel outside b g a GTP a GDP + Pi b g inside 22 Targets for Recreational Drugs amphetamine* phencyclidine cocaine nicotine neurotransmitter transporters neurotransmitter-activated channels postsynaptic cell GPCR N G protein-activated channels enzymes C a LSD morphine-heroin tetrahydrocannabinol caffeine* ?alcohol? (*= intracellular target) 23 Neurons that make dopamine; “pleasure/reward system” highlighted Nestler Figure 8-6 24 Seymour Benzer Thomas Hunt Morgan How do we study the fundamental bases of drug addiction? Drosophila melanogaster Ed Lewis 25 outside receptor membrane b g G protein i q s t a b g a inside effector channel enzyme The Central Dogma of Drugs and the Brain, Part 3: Drugs Activate Genes intracellular messenger Ca2+ cAMP cytosol kinase phosphorylated protein nucleus How fast? 10 s to days How far? Up to 1 m 26 Mid-Term Exam 27 Genomics and genetics in Bi 1 “Drugs and the Brain” 15, 17. Genomics 18. Implementing the Genetic Code: from DNA to Protein 20. Genetics: Formal and Molecular 21,22. Exemplar Simple Genetic Diseases: Cystic Fibrosis, long-QT syndrome, epilepsies 23. Stem cells and stem cell therapy 24. Another exemplar simple genetic disease: Huntington’s disease. 24,25 Schizophrenia, bipolar disorder, and the complex genetics of psychiatric diseases 27. Evolution 1: Inferences from Molecular Biology 28. Evolution 2: The eye as an example 28 Single-molecule measurements in genomics E = force x distance; force is generated by viscosity 29 Cystic Fibrosis: A Genetic Disease 1. Clinical description 2. Genetics 3. Gene structure 4. CFTR as a protein 5. Physiology of CFTR 6. What’s wrong with DF508? 7. The cholera connection 8. Selective advantage of CF? 9. Therapeutic approaches: Incremental approaches Gene therapy 30 David Helfgott plays Rachmaninov Piano Concerto #3 Copenhagen Philharmonic Orchestra, 1995 RCA Victor-BMG Classics as in the movie “Shine” Born in Melbourne 1947 1962-1970 several schizophrenic episodes 1966-70 Royal College of Music 1970-1980 Hospitalized in Australia 1984- present concert pianist According to the biography by his wife, his present medication consists of: D2 receptor blocker for schizophrenia; anticholinergic for tardive dyskenesia 31 Huntington’s Disease: Simple genetics, unknown mechanism Onset at 30-40 yr. Neurons in the striatum and cerebral cortex die, leading to movement disorders (“chorea”), dementia, and eventually death. Woody Guthrie 1912-1967 Mother died of Huntington’s chorea; Woody began suffering in ~ 1945 He had 8 children. 32 Bipolar Disease Vincent Van Gogh 1853-1890 750 paintings; 1600 drawings; 700 letters Life history: born and raised in the Netherlands. Paris 1886-88 Arles 1888 (1st episode; cut off his own ear); hospitalized 1888-1890 Auvers-sur-Oise 3 months. Shot himself 7/27/1890 1886 1887 1887-88 33 July 1890 34 Cell cycle and stem-cell therapy 35 Neurons that make dopamine die in Parkinson’s Disease Nestler Figure 8-6 36 Testing our understanding of evolution: the eye 37 “Study nature, not books” (Louis Agassiz) Flightless cormorant Voyages to the Galapagos 38 Final Exam 39 Bi 1 Fonts: Largest font size Medium font size Smallest font size (Slide projector sound) 40 Problem set #1 will be posted Tuesday on the Bi 1 Web Site; it’s a pdf. Due next Monday 4/3 11 AM in the Bi 1 Closet You might wish to inspect PS #1 before this week’s section meetings. Bi 1 Home Page: http://www.its.caltech.edu/~bi1/ Bi 1 Collaboration policies: http://www.its.caltech.edu/~bi1/Bi-1-policy-sheet.pdf 41 If you drop the course, or if you register late, please email Patricia Mindorff [email protected] (in addition to the Registrar’s cards). Also, if you want to change sections, please email Patricia Mindorff [email protected] Patricia Mindorff works 9 AM - 5 PM M-F 42