lecture 17 LOs

Question 1

in ‘drinker’ rats, what makes them this way

Answer 1

the dopamine system is much more responsive to alcohol than their counterpart non drinkers

Question 2

endogenous opioids contribute to reinforcing effects of alcohol, how

Answer 2

• acute alcohol increases endorphin and enkephalin production or release
• alcohol-induced opioid release may contribute to its ability to increase DA release
• chronic alcohol reduces opioid production which may contribute to he dysphoria that accompanies chronic alcohol use and withdrawal

Question 3

what do opioid receptor antagonists do to alcohol self administration

Answer 3

it reduces it

Question 4

what happens to mu opioid receptor knockout mice

Answer 4

they fail to self administer ethanol

Question 5

what is the mechanism of action for nicotine

Answer 5

acts as a direct agonist to active nicotinic cholinergic receptors
(excitatory effects on neural activity)

Question 6

what does nicotine do to non smokers

Answer 6

aversive effects, elicits heightened tension/arousal, lightheadedness, dizziness, nausea

Question 7

what does nicotine do to smokers

Answer 7

mild arousal (stimulant effect), calm or relaxed state (relief from withdrawal symptoms), appetite suppression

Question 8

what cog effects can nicotine have on attention

Answer 8

enhancing effects

Question 9

what NT plays a role in nicotine reinforcement

Answer 9

mesolimbic DA

Question 10

where do nicotine receptors reside

Answer 10

DA neurons cell bodies (to stimulate firing and increase NAc DA release)

Question 11

where does nicotine heteroreceptors reside

Answer 11

also on DA terminals in NAc (to increase transmitter release)

Question 12

what lesions attenuate nicotine self administration

Answer 12

DA terminals in NAc

Question 13

regarding nicotine, what happens when DA receptors are blocked

Answer 13

disrupts conditioned place preference to nicotine (measure of drug reward) and reinstatement of nicotine seeking, suggesting DA contributes to relapse

Question 14

what is a genetic way to prevent nicotine self administration

Answer 14

genetic knockout of certain nicotine receptor subtypes

Question 15

what are two examples of conditioned reinforcers for nicotine

Answer 15

sensory and temporal stimuli associated with the act of smoking become conditioned to reinforcing effects

Question 16

what is acute nicotine tolerance and what is it mediated by

Answer 16

smokers experience reduced effects of nicotine over the course of a day
mediated by desensitization of nicotinic receptors

Question 17

what is chronic tolerance

Answer 17

tolerance to aversive effects needs to occur for the smoker to experience the reinforcing effects of smoking
repeated nicotine also elicits compensatory up regulation of nicotinic receptors (triggered by acute desensitization), which can sensitize the system to nicotinic stimulation

Question 18

psychoactive and physiological effects of withdrawal

Answer 18

psychoactive: irritability, drowsiness/fatigue, difficulty concentrating, anxiety, depressed mood, increased hunger and craving sweets
physiological: headache, nausea, constipation, falling heart rate

Question 19

how do nicotine levels change throughout the day for smokers

Answer 19

early in the day there is increased plasma nicotine which elevates mood (above baseline), but later nicotine may merely maintain neutral mood (holding off the withdrawal symptoms)

Question 20

what are the sex differences for smoking

Answer 20

fewer women than men smoke
women tend to smoke fewer cigarettes a day, inhale less deeply, are more influenced by the non nicotine aspects of smoking, and find it tougher to stop smoking

Question 21

how does stress tie in to smoking

Answer 21

smokers say that smoking relieves stress and enhances ability to concentrate (nicotine resource model)

Question 22

what is the nicotine deprivation reversal model

Answer 22

positive effects of smoking represent alleviation of irritability, stress, and poor concentration experienced by smokers between cigarettes (ex during withdrawal)

Question 23

what is the medication buporpion used for

Answer 23

smoking cessation
acts as DA uptake inhibitor and weak nicotinic agonist

Question 24

what does the medication varenicline do

Answer 24

reduces nicotine cravings
partial agonist at high affinity nicotinic receptors expressed in the VTA and other brain areas

Question 25

how long does it take for caffeine to be absorbed by the GI tract, and what is its half life

Answer 25

30-60 mins for absorption
half life of ~ 4 hours

Question 26

what do humans experience at high levels of caffeine

Answer 26

feelings of tension and anxiety
in some cases at extremely high doses it can induce psychosis

Question 27

what are the physiological effects of acute caffeine intake

Answer 27

increased blood pressure and respiration
stimulation of catecholamine release from adrenal medulla
enhanced water excretion via suppression of antidiuretic hormone release

Question 28

what does caffeine withdrawal look like

Answer 28

symptoms include headache, fatigue, impaired concentration/psychomotor performance, mild anxiety or depression
despite its ability to produce physical dependence, caffeine use typically does not meet criteria necessary to be considered addictive
in general caffeine is tought to be quire safe when consumed at appropriate doses and coffee/tea may have some beneficial health effects