Chemistry of Behaviour

Question 1

Neurochemistry

Answer 1

chemical processes in the neurosystem (endogenous system, present in the system)

Question 2

Neuropharmacology

Answer 2

effects of drugs on neurosystem (exogenous processes, compound)

Question 3

Ionotropic receptor

Answer 3

• Ligand gated
• Opens ion channel
• Fast

Question 4

Metabotropic receptor

Answer 4

• G protein-coupled
• Second messengers: g protein activation
• Slow, longer lasting

Question 5

Receptors

Answer 5

protein molecules embedded in the postsynaptic membrane that recognize a specific transmitter

Question 6

Receptor agonist

Answer 6

drugs that block the transmitter and open gate -> normal effects of the transmitter on that receptor

Question 7

Competitive antagonist

Answer 7

neurotransmitter block the receptor and the agonist to act

Question 8

Non-competitive agonist/antagonist

Answer 8

they bind on different places

Question 9

Cholinergic pathways

Answer 9

Cholinergic pathways -> play a role in muscle control and memory

• Nicotine receptors -> ionotropic (important in muscular system)
• Muscarinic receptors -> metabotropic (role in memory)

Question 10

Dopaminergic pathways

Answer 10

• Mesostriatal pathway
  ○ From substantia nigra (black matter) to the striatum
  ○ Role in motor control
  ○ Main area affected in Parkinson’s disease
• Mesolimbocortical pathway
  ○ From VTA to limbic system
  Reward/reinforcement (change in dopamine level)

Question 11

Noradrenergic pathway

Answer 11

• Norepinephrine = noradrenaline, from locus coeruleus to broadly area in the brain
• Active role in body and the brain (sympathetic nervous system)
  ○ Connect neural system to the body (active response)
  ○ Activating mental functions in the brain

Question 12

Serotonergic (5-HT) pathways

Answer 12

• from raphe nuclei (in the midbrain)
• they project to mostly all the part of the brain -> control of mood, anxiety and sleep

Question 13

2 type of drugs

Answer 13

1) Medicine used in treatment of a disease
2) Drugs of abuse, used recreationally

Question 14

Effective dose 50 (ED50)

Answer 14

dose at which 50 % of the effect is shown or test population show effects (y or n)

Question 15

Lethal dose 50 (LD50)

Answer 15

dose at which 50 % of the population dies

Question 16

Therapeutic index

Answer 16

Window between ED50 and LD50.
The therapeutical index refers to the separation between useful doses of the drug and dangerous doses.

Question 17

Metabolic tolerance

Answer 17

organ system become more effective in eliminating the drugs from the bloodstream

Question 18

Functional tolerance

Answer 18

target tissue may show altered sensitivity to the drug (regulation of the number of receptors)

Question 19

Cross-tolerance.

Answer 19

Tolerance to a drug often generalised to other drugs belonging to the same chemical class

Question 20

sensitization

Answer 20

Some drugs responses can become stronger with repeated treatments, rather than weaker

Question 21

Regulation of the number of receptors for drugs

Answer 21

• When the drug is an agonist (increase activation) -> down-regulation (few receptor are needed for the same effect)
• When the drug is an antagonist -> up regulation of the number of receptors in the membrane (member of receptors became smaller)

Question 22

Antipsychotics

Answer 22

Antipsychotics -> affects post-synaptic neurons

Typical:
- Dopamine D2 antagonist
- Reduce positive symptom of schizophrenia

Atypical:
- S-HT antagonist
- Reduce negative symptoms of schizophrenia

Question 23

Antidepressants

Answer 23

Antidepressants -> use to cure depression

• MonoAmineOxidase (MAO) inhibitor: inhibits an enzyme in the presynaptic that inhibits the degradation of this neurotransmitter -> more neurotransmitter remaining present in the pre-synaptic cells and more available to be released.
• Tricyclic antidepressants: reuptake inhibitor -> not very specific (inhibit a lot) -> many inhibit path that don’t want to inhibit
• SSRI: selective serotonin reuptake inhibitor -> more specific and beneficial (increase serotonin -> benefit patient)

Question 24

Anxiolytics

Answer 24

Anxiolytics -> treat anxiety disorder (family of sedatives)

• Benzodiazepines: Gaba agonist that activate the same receptor as Gaba (inhibitor neuron) and reduce nervous system activity

Question 25

Moral model

Answer 25

drugs users can be blame for the abuse (lack of control), religion need to overcame abuse

Question 26

Disease model

Answer 26

drug abuse as a medical condition, difficult to find physical origin for drugs abuse (genetic predisposition?)

Question 27

Physical dependence model

Answer 27

people continue taking drugs for avoiding the symptoms of withdraw. This model don’t say anything about why people start initially

Question 28

Positive reward model

Answer 28

drugs make you feeling good -> feeling of reward