DRUG ABUSE AND ADDICTION

Question 1

definition:

seeking and taking drugs in spite of negative consequences or personal distress, with a varying loss of control

Answer 1

drug abuse/addiction

Question 2

characterize drug abuse

1.

2.

3.

Answer 2

1. a brain disorder
2. chronic and relapsing
3. powerful but treatable, and usually beatable

Question 3

describe the self-administration animal model

Answer 3

most drugs abused by humans are self-administered by animals in this model

useful for studying initiation of drug taking, maintenance, and relapse

suggests that drug taking is an innate drive

Question 4

which research model is critical for understanding biological basis for drug addiction

Answer 4

drug self-administration animal model

Question 5

self-administration it itself shows what?

Answer 5

an innate “hunger” for some drugs. many species have a vulnerability to drugs

Question 6

what characteristic of drug addiction does not eliminate humans as the singular species susceptible to this disease?

Answer 6

drug addiction has to do with neurochemical systems in the brain that are shared by many species

Question 7

how do drugs effect neuronal communication/neurotransmission (fast processes)?

Answer 7

alter release of neurotransmitter

alter receptor interaction

alter removal of neurotransmitter from the synapse

Question 8

how does cocaine cause rewarding effects?

Answer 8

1) cocaine binds to dopamine transporter and blocks reuptake in mesolimbocortical pathways, thus 2) potentiates dopaminergic neurotransmission, thus 3) cause the rewarding effects of drug

Question 9

name the two primary brain regions for addiction

Answer 9

nucleus accumbens

ventral tegmental area

amygdala

Question 10

describe how the brain overrides brain mechanisms

Answer 10

brain can manage availability and action of neurotransmitters, but cannot control drug levels, access to receptors or their duration of action

Question 11

dopamine receptors are coupled to what?

Answer 11

G proteins

Question 12

how do drugs change the brain/alter gene expression (cellular mechanism)?

Answer 12

signal transduction mechanisms alter transcription of mRNA, thus altering gene expression/protein levels and the function of the brain

(G-coupled proteins affect PKC initiation, and thus activation of transcription factors that alter gene expression)

Question 13

definition:

DNA-related changes in gene expression where ther are no mutations

Answer 13

epigenetics

Question 14

define DNA mutation

Answer 14

a change in a base/ permanent alteration of nucleotide sequence of the genome

Question 15

what are the two mechanisms of epigenetic change?

Answer 15

1. methylation of DNA which prevents translation
2. acetylation of histones that results in an opening of the chromatin so that translation/ gene transcription is facilitated

Question 16

what are the medications for PS abusers?

Answer 16

none approved yet.

often focus on DA to block euphoria, reduce withdrawal and negative mood, lessen cravings, and enhanc eimpaired cortical function

Question 17

substitute medication useful for curbing illegal cocaine use

Answer 17

RTI-336

Question 18

how is vaccine treatment work as a medication for substance abuse?

Answer 18

binds drug (cocaine) in the bloodstream, preventing entry into the brain

Question 19

how (specifically) does cocaine use effect the brain?

Answer 19

cocaine use reduces D2 levels.

*these levels tend to return to normal very slowly

Question 20

what two components of the mesocorticolimbic pathway regulate natural and biological rewards, including feeding, drinkin, love and sex, as well as conversion of emotion into motivated action?

(important for rewarding properties of cocaine)

Answer 20

1. nucleus accumbens
2. caudate-putamen

Question 21

what component of the mesocorticolimbic pathway regulates attention, mood, and emotions, and plays an important role in reward and reinforcement?

Answer 21

amygdala

Question 22

where in the mesocorticolimbic pathway do DA cell bodies originate?

Answer 22

VTA (ventral tegmental area)

Question 23

why do drugs have so much power over behavior?

Answer 23

drugs target powerful endogenous reward/reinforcement systems in the brain that are critical for survival