Principles Of Neuroscience Lecture 33 Drugs And The Brain Flashcards Preview

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Flashcards in Principles Of Neuroscience Lecture 33 Drugs And The Brain Deck (37)
0

What are the general features of psychoactive drugs?

Small
Lipophilic
Resemble endogenous chemicals

1

What are some common psychoactive drugs?

Ethanol
Caffeine
Nicotine
Heroine
Cocaine
LSD
Valium
Prozac

2

What are the two reasons that psychoactive drugs are used?

1. Pleasure - Hedonic drugs
2. Novelty - Psychadelic drugs

3

What are the features of hedonic drugs?

- addictive
- tolerance exhibited by the users

4

What are the features of psychedelic drugs?

- not as addictive as hedonic drugs
- not associated with tolerance

5

What is interesting about tobacco?

It is highly addictive, however, the users do not show tolerance

6

What aspects of brain function are affected by psychoactive drugs?

1. Behaviour
- psychomotor agitations
2. Mental function

7

Which functions of the PFC are altered by drugs?

- Motivation
- Perceived salience
- Emotional state
- Meaning and significance
- and vigilance
- Hedonic experience

8

How do psychoactive drugs act?

Since they are small and lipophilic, they can cross the blood brain barrier

There are chemical homologous in the brain with their own receptors. Drugs bind to see receptors and alter the kinetics of neurons

9

Describe what the research of opiate receptors lead to

Researchers were looking for the opioid receptor
Once they found it, they discovered the endogenous compound; endorphins

10

What are the different classes of neurotransmitters?

Amino acids: glutamate, glycine, GABA
Small amines: noradrenaline, acetylcholine
Peptides

11

What systems in the brain do psychoactive drugs work on?

The neuromodulatory systems

12

What is the effect of LSD?
How does it act in the brain?

LSD causes hallucinations, "mind expanding" experiences

Serotonin agonist

13

How do amphetamines and cocaine act in the brain?

These hijack the dopamine and noradrenaline systems

14

Which general features seems to be always seen in addictive drugs?

Give an example

Enhancement of the dopaminergic signal transduction

Eg. nicotine acts on nAChR, leading to increased dopamine

15

What are the four different types of connections between neurons?

Which does the neuromodulatory system use?

a. Simple - vision and motor control
b. Endocrine (big effect)
c. Amplification - ANS, preganglionic neurons controlling blood flow
d. Highly divergent (en passant) - the neuromodulatory systems

16

Describe the subtle action of drugs

The drugs bind to the metabotropic receptors in the neuromodulatory systems and subtle alter the kinetics and excitability of the neuron

They do not vastly change the activity of the neurons

17

Which sort of things does the serotonin system affect?

Mood
Appetite
Sleep

18

What is the nucleus in the serotonin neuromodulatory system?

Raphe nucleus in the brain stem

19

What is the nucleus in the dopamine neuromodulatory system?

Substantia nigra and Ventral tegmental area in the brain stem

20

Describe the action of cocaine on one of the neuromodulatory systems

Cocaine increases the concentration of dopamine at the synapse in the nucleus accumbens

21

Describe the action of heroin and nicotine on one of the neuromodulatory systems

Heroin and nicotine increase the action of the dopamine neurons in the VTA

22

What are the different causes of hallucinations?

- Schizophrenia
- Side effect of medication
- Marajuana
- Crack cocaine

23

Describe how seemingly different drugs can have similar effects

Marajuana and crack cocaine both cause hallucinations, even thought they are very different in function

24

Why is alcohol the biggest drugs problem?

It accounts for the most reduction in life span and deaths as well as it costs 4.5 billion dollars, over twice the cost of all illicit drugs

25

Describe the model of the effect of alcohol

Cause: volume drunk and patterns of drinking

Acute effects: intoxication -> injury, acute social and psychological problems
Chronic effects: dependence and toxicity -> chronic injury and social and psychological problems

26

What are some chronic diseases caused by alcohol?

Liver disease
Cancer
Diabetes
Neuro psychotic diseases (epilepsy, unipolar depression, PTSD, schizophrenia)
Diseases associated with drinking during pregnancy

27

What is the aetiology of FAS?

Alcohol crosses the blood brain barrier of the barrier; causing damage

28

What are the external features of FAS?

Simian crease
Flattened mid face
Low nose arch
Smooth upper lip
Small eye openings
Underdeveloped jaw

29

What are the internal features of FAS?

Small brain, large gap between the hemispheres

The prefrontal cortex is the most affected

30

How is FAS diagnosed?

1. Decreased cognitive function:
- academic
- concentration, impulsiveness
- learning disabilities
- memory
- maths skills
- social perception
- IQ below the 3rd pcentile
2. Anatomical features of the brain
- microcephaly
- hydrocephaly
- callosal dysgenesis
- migration abnormalities

31

Where does alcohol act in the brain?

On GABA receptors (different site to benzodiazepine)

32

What are the acute effects of alcohol acting in the brain? (4)

1. Potentiate as well as antagonise GABA's effects
2. Decrease GABA receptor density in the brain -> anxiety
3. Increases glutamate receptors in the hippocampus -> memory affected
4. Stimulates the release of serotonin (mood), endorphins (cravings) and dopamine (addiction)

33

What are the chronic effects of alcohol on the brain?

- Reduced brain volume, especially the white matter and PFC
- Thiamine deficiency
- Liver disease (hallmark of complicated alcoholics)

34

Describe what is meant by the coherent effects of psychoactive drugs

These drugs somehow do not cause massive disorganisation of brain activity, but have coherent, subtle effects on the brain

35

Give examples of why neurotransmitters are not solely responsible for functions of the brain

Serotonin not solely responsible for mood
Dopamine not solely a molecule that produces reward and pleasure

36

What are some Psychadelic drugs?

Marajuana, LSD

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