Agonist Antagonist Direct Agonist Indirect Agonist Direct Antagonist Exam Two Stuff drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell drug that opposes or inhibits a particular neurotransmitter on the postsynaptic cell drug that binds with and activates a receptor drug that attaches to a binding site on a receptor and facilitates the action of the receptor does not interfere with the binding site for the principal ligand a drug that binds with the receptor but does not activate it prevents the natural Noncompetitive Indirect Antagonist ligand from binding with the receptor drug that attaches to a binding site on a receptor and interferes with the action of the receptor does not interfere with the binding site of the principal ligand L DOPA form of dopamine often used to treat parkinsons disease because of its affect as a dopamine agonist Direct vs Indirect Reuptake Transporters ReUptake Inhibitor Drug prevents the neurotransmitter from being vacuumed up from the synapse Thus blocking termination of post synaptic potential Activating pre synaptic Drug blocks re uptake in presynaptic cell Ligand channels that need to attach to ions in order to open close 1 Pharmacokinetics is the process by which drugs are Absorption how drugs are absorbed in body Distribution how does it get around in body once its in there Distribution how the drug gets around in the body once it is there the drug has to make it into the brain for there to be a psychoactive effect hightly fat lipid soluble molecules have a much easier time crossing the Heroine is much more lipid soluble which causes it to get to the brain blood brain barrier more readily gets addicted Metabolism how the body alters the drug Metabolized biotransportation how the drug is changed by the body enzymes in liver generally refers to the biotransformation of a substance via an enzymatic or nonenzymatic process within the body to other molecular species Excretion piss test poop exhalation mainly through urinary system Kinetics issue is a primary issue determining a drug s effects route of administration how it affects plasma level Ex cociane smoked crack snorted powder or consumed orally original coca cola Pharmacodynamics Cell level actions of the drug Differentiate drug actions and drug effects micro vs macro Drug Actions are on a cellular level what that drug is actually doing micro ex cocaine is a drug uptake inhibitor Drug Effects Macro Large Scale ex saying cocaine is an antidepressant or adderall is psycho stimulant that revs you up DRCs disresponse curve and efficacy vs potency ED50 LD50 T I ED50 the dose needed to give the max response LD50 It is the amount of the substance required usually per body weight to kill 50 of the test population T I therapeutical index has to do with safety margin of drug how much is required to produce the effect how much is required to kill a person the ratio between the dose that produces the desired affect in 50 of the animals and the dose that produces toxic effects in 50 of the animals Potency how little of the drug you need to have an effect has to do with concentration higher T I the better Potency refers to the amount or dose of a drug required to produce a given effect Common measurements of dosage include milligrams and milliliters Potency is a way of comparing the effectiveness of different drugs Heroin is most potent small concentration still gives you a bigger high Efficacy used to describe how well a drug can produce a therapeutic response A drug for hypertension that lowers blood pressure more than another has greater efficacy for example Efficacy Dose of a drug to produce certain effect What is the max effect Tolerance and Withdrawal evidence of drug dependence Tolerance repeated administration means person needs more of a drug to reach the same effect Drug sensitization increase in the effectiveness of a drug that is administered repeatedly affects physiological processes Withdrawal negative or undesirable state when a person that is dependent on a drug tries to quit taking it They will experience negative emotional affective state To terminate the negative withdrawal symptoms then you can start the drug again re lapse Placebo effects Is REAL may include therapeutic and side effects People tend to expect what they think However it is psychological and has some physiological effects Accounts for of the effects of psychoactive drugs antidepressants Main features of the retina Retinal Transduction Retina light sensitive tissue lining the inner surface of the eye that creates an image of the visual world Located in rear portion of eyeball Photoreceptors and trichromatic encoding Transduction process of translating environmental energies into neural signals Two types of photoreceptors Cones Rods require bright light are wavelength sensitive are concentrated in the fovea the central aspect of retina They have three photo pigments Have much lower activation thresholds Good at detecting motion not at detecting color form or shape Concentrated back of the the retina Readily respond to low intensity light and movement Immediately bleach in presence of white light require 30 sec to fully recover most strongly absorbs green blue light Three main cell layers of eye photoreceptors are neurons that process light specialized type of neuron found in retina capable of phototransduction convert light into signals that stimulate biological processes Bipolar cells transmit signals from photoreceptors to the ganglion cells Ganglion cells receives visual information from the photoreceptors transmits visual information from the retina to the different parts of the brain thalamus hypothalamus midbrain Characteristics of Retina Retina is part of the CNS so its part of the brain There are ten different pathways for vision to perceive from retina to rest of brain It is the rear portion of the eyeball Axons exit the retina to carry transduced and partially encoded visual signal back to rest of brain REMEMBER THERE ARE TEN DIFFERENT PATHWAYS IN HUMANS Light sensitive part of the back of the eye Ex Fovea Blind Spot etc Can get blind site on both sides of eye fovea central region of retina which mediates most acute vision this contains only cones blind spot is produced by the optic nerve because no receptors are located there Primary pathway for conscious vision cranial nerve II Characteristics of V1 and visual association cortex dorsal vs ventral pathways small modules