PSYC 223 Biological Psychology - Drug Activity PDF

PSYC 223 BIOLOGICAL PSYCHOLOGY Session 3 – DRUG ACTIVITY IN THE NERVOUS SYSTEM Lecturer: Dr. Adote Anum, Dept. of Psychology Contact Information: [email protected] College of Education School of Continuing and Distance Education 2014/2015 – 2016/2017 ...

PSYC 223 BIOLOGICAL PSYCHOLOGY Session 3 – DRUG ACTIVITY IN THE NERVOUS SYSTEM Lecturer: Dr. Adote Anum, Dept. of Psychology Contact Information: [email protected] College of Education School of Continuing and Distance Education 2014/2015 – 2016/2017  Session Overview So far we have discussed transmission across neurons which occurs at the synapse. The process of chemical process is quite similar when other chemicals or drugs enter the nervous system. Drug activity in the nervous causes effects that are similar to the effects of neurotransmitters. In this session, the discussion of drugs will cover the different classifications of drugs, the active compound in drugs, and the behavioral effects of the drugs. Slide 2  Session Outline The key topics to be covered in the session are as follows: Drug classification Drug activity in the Synapse Stimulant Drugs Depressant Drugs Hallucinogenic Drugs Slide 3  Reading List Read Chapter Three of Biological Psychology 9th Edition by J. W. Kalat; pages 70 – 78 Kolb, B. & Whishaw, I. Q. (2013). An Introduction to Brain and Behavior, 4th Edition. McMillan Learning. Slide 4 Topic One DRUG ACTIVITY IN THE NERVOUS SYSTEM Slide 5  Classification of Psychoactive Drugs Psychoactive drugs are drugs that affect … Sedative Hypnotics and Anti-anxiety Agents – Causes drowsiness and relaxes; e.g., Valium Antipsychotic Agents – Treatment for psychotic disorders; e.g., phenothiazine Antidepressants – Treats depression; e.g., Fluxetine Mood Stabilizers – Treats mood disorders; e.g., lithium, carbamazepine Narcotic Analgesics – Pain killers that stop pain in the brain; e.g., morphine Psychomotor Stimulants – Psychomotor stimulants; e.g., cocaine Psychedelics and Hallucinogens – Causes hallucinations, distort reality; e.g., LSD, cannabis  Drugs and the Synapse The study of the influence of various kinds of drugs has provided us with knowledge about many aspects of neural communication at the synaptic level. Drugs either facilitate or inhibit activity at the synapse. – Antagonistic drugs block the effects of neurotransmitters (e.g., novacaine, caffeine). – Agonist drugs mimic or increase the effects of neurotransmitters (e.g., receptors in the brain respond to heroin, LSD and cocaine) Drugs alter various stages of synaptic processing. Topic Two DRUG ACTIVITY AT THE SYNAPSE Slide 8  Drugs and the Synapse Drugs work by doing one or more of the following to neurotransmitters: 1. Increasing the synthesis. 2. Causing vesicles to leak. 3. Increasing release. 4. Decreasing reuptake. 5. Blocking the breakdown into inactive chemical. 6. Directly stimulating or blocking postsynaptic receptors. Topic Three STIMULANT DRUGS Slide 10  Drugs and the Synapse Drugs are categorized according to their predominant action or effect upon behavior Stimulant drugs increase excitement, alertness, motor activity and elevate mood. Examples: amphetamines, cocaine, methylphenidate (Ritalin), MDMA (Ecstasy), nicotine Stimulant drugs directly stimulate dopamine receptor types D2, D3, and D4.  Drugs and the Synapse Amphetamine stimulate dopamine synapses by increasing the release of dopamine from the presynaptic terminal. Cocaine blocks the reuptake of dopamine, norepinephrine, and serotonin. Methylphenidate (Ritalin) also blocks the reuptake of dopamine but in a more gradual and more controlled rate.  Drugs and the Synapse Nicotine stimulates one type of acetylcholine receptor known as the nicotinic receptor. Nicotinic receptors are found in the central nervous system, the nerve-muscle junction of skeletal muscles and in the nucleus accumbens (facilitate dopamine release). Topic Four DEPRESSANT DRUGS Slide 14  Depressants They reduce arousal in the nervous system – By either blocking receptors – Or preventing the activity of excitatory neurotransmitters Slide 15  Depressants Examples of depressants – Barbiturates – Alcohol – Benzodiazepines Topic Five HALLUCINOGENIC DRUGS Slide 17  Psychedelic drugs Psychedelic drugs are alter sensory perception and cognitive processes. For example, they may cause hallucination or enhance perceptions The common types are: – Tetrahydrocannabinol (THC): active ingredient in marijuana – Serotonin psychedelics (e.g., lysergic acid diethylamide) – Norepinephrine psychedelics (e.g., mescaline)  Marijuana Tetrahydocannabinol (THC) is the active ingredient in marijuana. THC attaches to cannabinoid receptors throughout the brain but especially the cerebral cortex, cerebellum, basal ganglia, and hippocampus. Slide 20  References Read Chapter Three of Biological Psychology 9th Edition by J. W. Kalat; pages 70 – 78 Read Chapters Four and Five of An Introduction to Brain and Behavior, 4th Edition. McMillan Learning, by Kolb, B. & Whishaw, I. Q. (2013). Slide 21