Alcohol

Question 1

Alcohol is a CNS depressant, what does this mean?

Answer 1

has an overall inhibitory effect on neural activity and arousal

Question 2

is alcohol quickly absorbed into the blood?

Answer 2

yes

Question 3

alcohol has dose dependent effects, what happens at:
- 0.5 g/l
- 0.8 g/l
- 1.5 g/l

Answer 3

0.5 = anxiolytic, social lubricant
0.8 = impaired motor and cognitive function
1.5 = ataxia, blackouts

Question 4

what is ataxia

Answer 4

staggering or slurred speech

Question 5

what is a lethal blood concentration of alcohol

Answer 5

3-4 g/l

Question 6

what is alcohols effect on dopamine

Answer 6

release

Question 7

what does increased dopamine signal

Answer 7

increased activity of the mesolimbic dopaminergic pathway - positive reinforcement, motivation, reward anticipation

Question 8

what does acute alcohol do to GABA

Answer 8

enhanced GABA inhibition = anxiolytic effects

Question 9

what does acute alcohol do to glutamate, how?

Answer 9

reduces glutamatergic activity

• NMDA receptor antagonist

Question 10

what type of memory is unaffected by alcohol consumption

Answer 10

implicit

Question 11

how does alcohol affect memory

Answer 11

suppresses the firing of hippocampal place cells

Question 12

how does neurotoxicity arise? in the example of glutamatergic neurons

Answer 12

alcohol reduces glutamatergic activity

the neuroadaptive response is to upgrade NMDA receptors

cessation of drinking causes NMDA receptor overactivity

this causes a large calcium influx into cells which causes hyper excitability and cell death.

Question 13

how does alcohol dependency arise

Answer 13

compulsion to seek and take the drug
loss of control in limiting intake
negative emotions when access to the drug is denied

Question 14

why is addiction quick in alcohol?

Answer 14

because it reaches the brain fast = immediate high

Question 15

how does reinforcement mediate addiction

Answer 15

liking is associated with wanting
- learned association between anticipation and positive reinforcement
- chronic use leads to reinforced wanting
- wanting turns to craving behaviour

Question 16

what is the role of mesolimbic dopaminergic system in addiction

Answer 16

becomes hyper-responsive
- drug cues trigger craving and increased salience
- increased motivation for alcohol seeking behaviour

Question 17

what happens to receptors in chronic alcohol use

Answer 17

NMDA receptors become hypersensitive to glutamate
GABAergic receptors become desensitised

Question 18

how does tolerance arise?

Answer 18

the impairing effects are reduced which has reinforcing properties = reduced pleasure

means that higher doses are needed to produce the same effects

Question 19

how are the withdrawal effects caused?

Answer 19

reduced synaptic GABA activity lowers inhibition of the neuron

this creates anxiety behaviours and hyper excitability

Question 20

what are the late stages of alcohol dependence

Answer 20

significant reduction in the volume of brain regions - prolonger periods of abstinent can lead to recovery

• this leads to cognitive deficits