Chapter 3 2 and 3 3 In general all drugs of abuse cause dopamine release in the nucleus accumbens Okay not a question but KNOW THAT Stimulants know some examples of stimulant drugs What neurotransmitters do they increase What are some behavioral effects Some stimulant drugs include Amphetamine Cocaine Ritalin Ectasy serotonin Excitement activity alertness mood and fatigue Cocaine what is its method of action ie what does it do at a synapse Cocaine blocks transporter What does Ritalin do at the synapse How is it different from cocaine Ritalin also blocks transporter What does ecstasy do at the synapse What are the effects of long term use neurons What are some psychological cognitive effects Know examples of hormones that ecstasy affects and the behavioral result Stimulant at low doses increases dopamine release and norepinephrine at higher doses serotonin is released Long term effects increased blood pressure and heart rate pupil dilation and release of posterior pituitary hormones Psychological effects euphoria well being happiness stimulation increased energy extroversion feeling close to others increased empathy increased sociability enhanced moods mild perceptual disturbances changed perception of colors and sounds What is serotonin syndrome Understand why drug interactions could cause it Serotonin syndrome is when too much serotonin is released into the body b c of too much of a serotonin agonist or b c mixing drugs that all act in some capacity as serotonin agonists Drug interactions could cause it because neurotransmitters are more readily available What type of receptor does nicotine use What is the effect of long term nicotine use on dopamine cells Stimulates nicotinic Ach receptor on VTA neurons thereby exciting them VTA neurons project to nucleus accumbens and release dopamine Cells become less responsive than usual after repeated nicotine use therefore other pleasures become less reinforcing Opiates know some example What receptor do they use What is the endogenous ligand of those receptors in other words we don t have those receptors so we can use heroine why do we have them How do opioids increase dopamine in n accumbens What is methadone how does it work and why is it used clinically Examples Morphine Heroin Methadone The endogenous ligand of those receptors are endorphins Opiate drugs increase dopamine by binding to opioid receptors in nucleus accumbens and on GABA neurons in VTA GABA usually inhibits Da neurons in VTA that project to NA inhibit the GABA which disinhibits dopamine neurons Methadone is taken to combat opioid addiction It is similar to heroin and morphine taken as a pill so it enters the blood and brain slowly which means no rush it is also metabolized slowly which means there is no crash Methadone is still highly addictive but it is less dangerous than heroin or morphine It is combined with naloxone so people don t just inject the methadone Naloxone blocks opioid effects if injected and is broken down in stomach acids if taken orally Cannabinoids How do they increase dopamine in n accumbens What are some medicinal uses What are some psychological effects What are some withdrawal symptoms reported by heavy smokers Cannabinoids are marijuana They inhibit GABA in VTA which releases more dopamine to the nucleus accumbens Medicinal uses pain relief and appetite stimulant Psychological effects intense sensory experiences and illusion of time passing slowly Heavy smokers do report withdrawal symptoms after long term use such as anxiety depression stomach pain craving loss of appetite and sleep problems Alcohol What does it do to GABA transmission and how What does it do to glutamate transmission Combines with GABA to produce longer normal effects of GABA opens Cl channel wider than usual Glutamate receptor antagonist so depressant in this way too What is tolerance How does the brain respond to other natural reinforcers when tolerance has developed to a drug Tolerance is a decrease in the effectiveness of a drug that is administered repeatedly As tolerance develops to the drug the individual becomes less responsive to other types of reinforcement as well Why do people experience cravings to a drug even after withdrawal symptoms have subsided Because withdrawal symptoms will occur without the drug so people stop using it as much for pleasure but to avoid displeasure What is sensitization What does it mean that cocaine causes sensitization in the nucleus accumbens Sensitization is an increase in the effectiveness of a drug that is administered repeatedly Repeated cocaine use increased dopamine release in nucleus accumbens with each use How is the prefrontal cortex involved in decreased reinforcement from other pleasurable things Lots of drug use is inhibitory to Prefrontal Cortex Prefrontal Cortex can t stimulate nucleus accumbens to facilitate reinforcement Define alcoholism What are the differences between Type I and Type II alcoholism Alcoholism is the continued use of alcohol despite medical or social harm even after having made a decision to quit or decrease drinking Type one later onset gradual onset fewer genetic relatives with alcoholism equal quantity between men and women less severe Type two earlier onset more rapid onset more genetic relatives with alcoholism men outnumber women often severe often associated with criminality What 2 genes could be involved in alcoholism Gene for a dopamine receptor and gene for enzyme that breaks down dopamine What are some risk factors for becoming an alcoholic People who were described in childhood as impulsive risk taking easily bored sensation seeking and outgoing Sons of alcoholics have specific traits relating to how alcohol affects them and their neuroanatomy Decreases stress more than for other people smaller amygdala on the right What are the medications used for alcoholism and how do they work What is the major limiting factor to their efficacy I ll give you this one they only work in people who are very motivated to quit drinking Antabuse is a medication used to combat alcoholism It converts the ethyl alcohol converts it to acetaldehyde and instead of converting it to acetic acid it is converted to acetaldehyde dehydrogenase which makes you sick Development plasticity and brain damage What is the neural tube and what will it become Neural tube is a hollow space within the embryo and it becomes the ventricular system What part of the brain develops for the longest amount of time Prefrontal cortex What
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