Pharmacology of neurotransmitters

Question 1

Are cations excitatory or inhibitory in AP?

Answer 1

Excitatory

Question 2

Are anions excitatory or inhibitory in AP?

Answer 2

Inhibitory

Question 3

Basic role of adrenaline in the body

Answer 3

Increase HR and blood flow

Question 4

Basic role of noradrenaline in the body

Answer 4

Vasoconstriction

Question 5

Basic role of dopamine in the body

Answer 5

feelings of pleasure, addiction, movement, motivation

Question 6

Basic role of serotonin in the body

Answer 6

well-being, happiness, sleep cycle, digestive system regulation

Question 7

What is the monoamine hypothesis’

Answer 7

deficiency of monoamine neurotransmitters causes depression

Question 8

Evidence for the monoamine hypothesis

Answer 8

Drugs that restore brain monoamine levels are effective antidepressants
Drugs that reduce brain monoamines (e.g. reserpine, clonidine) cause depression

Question 9

Evidence against the monoamine hypothesis

Answer 9

Antidepressants increase monoamines immediately but clinical benefits can take weeks
35% benefit in first week
benefit may be due to longer term downstream actions of monoamines on cellular protein expression
Not all depression responds to antidepressants
It’s an oversimplification
Other mechanisms e.g. hypothalamic- pituitary-adrenal/thyroid axis involved

Question 10

what breaks down monoamines

Answer 10

monoamine oxidase

Question 11

example of tricyclic antidepressent

Answer 11

amitriptyline

Question 12

MOA of TCA

Answer 12

block reuptake of monoamines

Question 13

Example of SSRI

Answer 13

citalopram, sertroline

Question 14

example of serotonin and noradrenaline reuptake inhibitor

Answer 14

duloxetine

Question 15

example of noradrenaline reuptake inhibitor

Answer 15

reboxetine

Question 16

example of a monoamine oxidase inhibitor

Answer 16

moclobemide

Question 17

describe the mesolimbic pathway of dopamine

Answer 17

Mesolimbic pathway – dopamine produced in ventrotegmental area is released in the nucleus accumbens and amygdala

Responsible for motivation and reward

This pathway is thought to be overactive in addiction and mood disorders

Question 18

Role of nucleus accumbens

Answer 18

pleasure seeking, reward behaviour

Question 19

role of the amygdala

Answer 19

negative symptoms: aggression, fear

Question 20

describe the mesocortical pathway for dopamine

Answer 20

Mesocortical pathway– dopamine produced in ventrotegmental area is released in the prefrontal cortex

Responsible for cognitive control, motivation, and emotional response

This pathway is associated with negative symptoms of schizophrenia, which include avolition, alogia and flat affect

Question 21

what is avolition

Answer 21

no motivation

Question 22

what is alogia

Answer 22

not speaking

Question 23

describe the nigrostriatal pathway of dopamine

Answer 23

Nigrostriatal pathway – dopamine produced in substantia nigra is released in the basal ganglia

Responsible for motor coordination

This pathway is underactive in Parkinson’s disease

Question 24

describe the tuberoinfundibular pathway of dopamine

Answer 24

Tuberoinfundibular pathway (AKA tuberohypophyseal)– projects from the infundibular nucleus in the tuberal region of the hypothalamus to the median eminence of the hypothalamus

Dopamine is released into the hypophyseal portal system which supplies the pituitary gland

Negative feedback for prolactin

Responsible for feedback mechanism of lactation

Question 25

Match: ... uses ... -basal ganglia -motor cortex ___________________________ -Ach -dopamine

Answer 25

basal ganglia- dopamine motor cortex- Ach

Question 26

role of dopamine in movement

Answer 26

regulates movements- upregulates movements you want, downregulates ones you don’t

Question 27

symptoms associated with low dopamine and high ACh

Answer 27

tremor rigidity bradykinesia

Question 28

treatment for Parkinsons

Answer 28

``` Raise dopamine: Dopamine precursor L Dopa (+ dopa decarboxylase inhibitor) Releases dopamine e.g. amantadine Dopamine agonists e.g. ropinirole, cabergoline, rotigotine ``` ``` Lower Ach: Antimuscarinic drugs Block Ach receptors benzatropine procyclidine orphenadrine ```

Question 29

Why give dopa decarboxylase inhibitors alongside levodopa

Answer 29

as without it the drug would be broken down before it crosses the BBB

Question 30

role of the prefrontal cortex

Answer 30

regulates attention and cognition

Question 31

example of first generation/ typical antipsychotics

Answer 31

haloperidol | chlorpromazine

Question 32

MOA of 1st generation/typical antipsychotics

Answer 32

block D2 receptors in mesolimbic/mesocortical, nigrostriatal and tuberoinfundibular pathways and chemoreceptor trigger zone (brain stem)

Question 33

example of 2nd generation/atypical antipsychotics

Answer 33

olanzapine risperidone clozapine

Question 34

MOA of 2nd generation/atypical antipsychotics

Answer 34

block D2 receptors in mesolimbic/mesocortical pathway,

Question 35

examples of extrapyramidal side effects

Answer 35

Parkinsonism Akathisia Tardive dyskinesia

Question 36

side effects caused by blocking the tuberoinfundibular pathway

Answer 36

gynaecomastia galactorrhoea menstrual disturbance

Question 37

basic role of Ach in the body

Answer 37

thought, learning and memory. activates muscle action in the body

Question 38

NTs of SNS

Answer 38

adrenaline and noradrenaline

Question 39

Role of SNS

Answer 39

inc CO, bronchodilation, pupillary dilation, reduce digestion and absorption and reduce renal elimination

Question 40

NTs of PNS

Answer 40

ACH

Question 41

Role of PNS

Answer 41

normalise CO, normalise bronchodilation, pupillary constriction, increase absorption and digestion and increased renal elimination

Question 42

side effects of antimuscarinics

Answer 42

dry mouth constipation urinary retention increased intraocular pressure

Question 43

basic pathology of Alzheimer's disease

Answer 43

loss of cholinergic neurons decreased acetylcholine levels reduced choline acetyltransferase (Ach synthesising enzyme) cognitive impairment correlates with loss of cholinergic input

Question 44

example of cholinesterase inhibitor

Answer 44

donepezil rivastigmine galantamine

Question 45

basic role of GABA in the body

Answer 45

high levels improve focus, low levels cause anxiety. contributes to motor control and vision. Inhibitory NT