Textbook Notes (363,107)
Canada (158,199)
Psychology (9,568)
PSYD35H3 (12)
Chapter 2

Chapter 2 notes- detailed (Pharmacodynamics)

3 Pages
Unlock Document

University of Toronto Scarborough
Nussbaum D

PSYD35- A Primer of Drug Action, 12 Edition (2010) CHAPTER 2- PHARMACODYNAMICS  What drug does to bodybind to receptorsdrug binding is usually both ionic and reversible--- strength of ionic attachment is determined by how well fit of drug structure to site on receptor  When drug binds to receptor, two responses: immediate response to presence or 2) when drug given over long period, long term changes occur  Immediate response: nicotine (releases DA), Ritalin for ADHA, sedatives for insomnia—action for these are acute agonists at specific receptors  Long term—neurons adapt to drug, causing long-term changes (anxiety, depression)  Receptor: large molecule; endogenous compounds (neurotrans) float around and do their thing  Drugs have effect by binding to receptor and affecting availability of neurotrans and other chemicals at that area  15+ 5H receptors  Buspirone attaches to 5H1a (anti anxiety and antidepressant)  Binding drug to receptor causes either: binding to receptor site usually occupied can cause response similar to drug (drug mimics action of transmitter)---agonistic action Binding to site near endogenous neurotrans site (allosteric action) binding to receptor usually occupied, but blocking (antagonistic action)  General rule: drugs don’t create effects, only modulate normal neuronal functioning (e.g. schizo drugs are D2 antagonists—prevent endogenous release) RECEPTOR STRUCTURE:  Ion Channel Receptor (inotropic): receptor forms a pore that enlarges when NT or exogenous chemical attaches to receptor-binding site5 section (subunits-a,b,a,y,d)each section is made up of 4 helical coils with also cross membrane and are labelled (M1-M4)—The arrangement of these 5 units form the channel of the receptorBenzos are agonists that bind to site near GABA site and increase flow of chloride ions into neuron (hyperpolarizing)—drug flumazenil attach to benzo antagonist—It displaces benzo from receptor  G-Protein-Coupled Receptors (metabotropic): activate receptor->release intracellular protein (G) that controls enzyme function in post synaptic neuronthrough series of enzynamic process opens/closes ion channels located elsewhere on cell membrane Structure: single protein chain of 400-500 aa coils the NT/drug attaches inside space between coils Process: NT/drug bind to receptorchanges shape of receptorNT/drug binds to the G- protein in cell membraneactivates G G can directly activate ion channel or trigger chemical reasons that will cause the G protein to move across membrane and the (indirectly) activates enzyme adenylyl cyclaseproduces lots of AMPspreads signal through cellaffects ion channelsAMP is the second messenger (first being the NT/drug)  By using AMP, a small weak signal from outside can create a strong signal within (e.g. don’t need much NT)  Carrier Proteins: transports small organic molecules across cell membrane against concentration gradients Presynaptic carrier: bind DA,NE, or 5H in cleft and transport them back into presynaptic terminal—terminating transmission Structure: chains of aa arranged as 12 helical of aa Study: found that in order to move against gradient the transporters must exist in atleast3 states: open to the synapse, obstructed with the NT inside, and open to cytoplasm of presynaptic celltransporter is bowl-shaped; fluid filled basinresting state: bowl is open to cleft, traps one/more molecules, allowing floods of molecules to move from cleft into terminal  See page 47
More Less

Related notes for PSYD35H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.