NEUROTRANSMISSION

Question 1

What is the main excitatory neurotransmitter in the central nervous system?

Answer 1

Glutamate

Question 2

Name four main receptor subtypes for glutamate.

Answer 2

NMDA, AMPA, Kainate, Metabotropic receptors

Question 3

Are NMDA, AMPA, and Kainate receptors ionotropic or metabotropic?

Answer 3

Ionotropic

Question 4

Why is glutamate recycling important for neurons?

Answer 4

It maintains optimal neurotransmitter levels in the synapse, prevents overstimulation, and prevents excitotoxicity and neuronal damage

Question 5

What effect do NMDA antagonists have?

Answer 5

They block the activity of NMDA receptors, involved in synaptic plasticity, memory formation, and various pathological processes

Question 6

How do NMDA antagonists affect memory function?

Answer 6

Excessive blockade of NMDA receptors can impair memory function

Question 7

What are some clinical applications of NMDA receptor antagonists?

Answer 7

Treatment of epilepsy, schizophrenia, depression, Alzheimer’s disease

Question 8

Which conditions is GABA important for regulating?

Answer 8

Epilepsy, anxiety disorders, certain types of movement disorders

Question 9

How is GABA synthesized and deactivated?

Answer 9

Synthesized from glutamate by glutamic acid decarboxylase (GAD); deactivated through reuptake and degradation by GABA transaminase (GABA-T)

Question 10

How can a drug be devised to increase GABA levels?

Answer 10

Both GABA transaminase inhibitor and GABA reuptake inhibitor would effectively increase GABA levels in the synapse, enhancing inhibitory neurotransmission

Question 11

What conditions do benzodiazepines treat?

Answer 11

Anxiety disorders, panic attacks, insomnia, muscle spasms

Question 12

How do benzodiazepines enhance inhibitory neurotransmission?

Answer 12

They act as positive allosteric modulators of the GABA alpha receptor, increasing the inhibitory effects of GABA on neuronal activity

Question 13

What is the function of the GABA alpha receptor?

Answer 13

It is a ligand-gated chloride ion channel responsible for fast postsynaptic inhibition

Question 14

How does vigabatrin affect GABA levels in the brain?

Answer 14

It inhibits GABA transaminase, thereby increasing GABA levels in the brain

Question 15

What is the function of the GABA beta receptor?

Answer 15

It is a G-protein-coupled receptor that inhibits calcium influx, activates potassium channels, and inhibits neurotransmitter release

Question 16

What neurotransmitter is associated with the noradrenergic system?

Answer 16

Norepinephrine (noradrenaline)

Question 17

What functions are regulated by the noradrenergic system?

Answer 17

Attention, arousal, stress responses

Question 18

What neurotransmitter is associated with the serotonergic system?

Answer 18

Serotonin

Question 19

What functions are regulated by the serotonergic system?

Answer 19

Mood, sleep, appetite, various physiological functions

Question 20

What neurotransmitter is associated with the dopaminergic system?

Answer 20

Dopamine

Question 21

What functions are regulated by dopaminergic neurons from the substantia nigra?

Answer 21

Motor control, affected in Parkinson’s disease

Question 22

What functions are regulated by dopaminergic neurons from the ventral tegmental area?

Answer 22

Reward, motivation, addiction

Question 23

What neurotransmitter is associated with the cholinergic system?

Answer 23

Acetylcholine

Question 24

What functions are regulated by the cholinergic system?

Answer 24

Memory, attention, learning

Question 25

What are autoreceptors?

Answer 25

Receptors located on the presynaptic neuron that regulate the release of neurotransmitters

Question 26

What is the function of autoreceptors when activated?

Answer 26

They inhibit cell firing and transmitter release at the terminal regions

Question 27

What are the autoreceptor subtypes for serotonin (5-HT)?

Answer 27

5-HT1A, 5-HT1D (also known as 5-HT1B)

Question 28

What are the autoreceptor subtypes for dopamine?

Answer 28

D2 or D3

Question 29

What are the autoreceptor subtypes for noradrenaline?

Answer 29

α2

Question 30

How does reserpine affect noradrenaline (NA) levels?

Answer 30

Depletes NA stores by inhibiting vesicular uptake, interfering with packaging into synaptic vesicles

Question 31

How does amphetamine affect noradrenaline (NA) levels?

Answer 31

Enters synaptic vesicles, displaces NA into cytoplasm, increases leakage of NA, elevating extracellular levels

Question 32

How does cocaine affect noradrenaline (NA) levels?

Answer 32

Blocks reuptake of NA, leading to increased levels in synaptic cleft, prolongs action and enhances effects on postsynaptic receptors

Question 33

What type of neurotransmitter is noradrenaline?

Answer 33

Monoamine

Question 34

What are the actions of noradrenaline on receptors?

Answer 34

Both inhibitory (acting on β receptors) and excitatory (acting on α and β receptors)

Question 35

How is noradrenaline terminated after release?

Answer 35

Neuronal uptake and degradation by monoamine oxidase (MAO)

Question 36

Where are the main cell bodies for noradrenergic neurons located?

Answer 36

Locus coeruleus

Question 37

During which state are noradrenergic neurons particularly active?

Answer 37

Wakefulness

Question 38

What effect do drugs like amphetamine have on noradrenaline activity?

Answer 38

Increase alertness and exploratory behavior

Question 39

In which brain regions does noradrenaline have a high density of receptors?

Answer 39

Brainstem, hypothalamus, medial temporal lobe

Question 40

What functions is noradrenaline involved in?

Answer 40

Arousal, wakefulness, exploration, mood regulation, blood pressure regulation, addiction, gambling behaviors

Question 41

What is the association between low levels of noradrenaline and depression?

Answer 41

Low levels of noradrenaline are associated with depression

Question 42

What type of neurotransmitter is dopamine?

Answer 42

Monoamine

Question 43

How does dopamine primarily affect central neurons?

Answer 43

By acting on potassium (K+) channels to inhibit them

Question 44

What are the two main families of dopamine receptors?

Answer 44

D1 receptors (including D1 and D5 subtypes) and D2 receptors (including D2, D3, and D4 subtypes)

Question 45

Where are D3 receptors primarily located?

Answer 45

In the limbic system, but not in the striatum

Question 46

How is dopamine neurotransmission terminated?

Answer 46

By degradation through the enzyme monoamine oxidase (MAO) and reuptake into presynaptic terminals

Question 47

Name two main pathways in the brain involving dopamine.

Answer 47

From the substantia nigra to the basal ganglia and from the midbrain to the limbic cortex

Question 48

What roles does dopamine play in physiological and behavioral functions?

Answer 48

Movement control, addiction, stereotypy, hormone regulation, vomiting

Question 49

What neurological disorder is associated with dysfunction in the dopamine system?

Answer 49

Parkinson's disease

Question 50

What psychiatric disorder is associated with abnormalities in dopamine function?

Answer 50

Schizophrenia

Question 51

What type of neurotransmitter is serotonin (5-HT)?

Answer 51

Monoamine

Question 52

How many known subtypes of serotonin receptors are there?

Answer 52

14

Question 53

Which subtype of serotonin receptors is excitatory and found in the limbic system and cortex?

Answer 53

5-HT2 receptors, particularly 5-HT2A

Question 54

Where are 5-HT3 receptors located, and what are they associated with?

Answer 54

Located in the medulla and associated with vomiting

Question 55

What is the termination process for serotonin neurotransmission?

Answer 55

Degradation through the enzyme monoamine oxidase (MAO) and reuptake into presynaptic terminals

Question 56

Name three physiological and behavioral functions regulated by serotonin.

Answer 56

Mood regulation, psychosis, sleep-wake cycle

Question 57

What psychiatric disorder is associated with imbalances in serotonin levels?

Answer 57

Anxiety and depression

Question 58

Which serotonin receptor subtype is targeted by antipsychotic medications?

Answer 58

5-HT2A

Question 59

What role does serotonin play in pain pathways and migraine?

Answer 59

Inhibits pain pathways and can act synergistically with opioids to alleviate pain

Question 60

What are the main histamine receptor subtypes and their functions?

Answer 60

H1 receptors (involved in arousal) and H3 receptors (presynaptic, constitutively active)

Question 61

What are the functions of histamine in the central nervous system?

Answer 61

Regulation of sleep-wake cycles and involvement in vomiting

Question 62

Name two purines and their receptor subtypes.

Answer 62

Adenosine (acts on A1 and A2A/A2B receptors) and ATP (acts on P2X receptors)

Question 63

What are the functions of adenosine in the central nervous system?

Answer 63

Regulation of sleep, pain modulation, neuroprotection, addiction, seizures, anticonvulsant effects

Question 64

Name three types of opioid receptors and their functions.

Answer 64

μ, δ, and κ receptors. Functions include pain modulation.

Question 65

What neuropeptides act on tachykinin receptors, and what are their functions?

Answer 65

Substance P (acts on NK1 receptors), neurokinin A (acts on NK2 receptors), and neurokinin B (acts on NK3 receptors). Functions include modulation of pain pathways.

Question 66

What type of receptors do endocannabinoids act on, and what are their effects?

Answer 66

Endocannabinoids act on CB1 receptors, inhibiting GABA and glutamate release. They are involved in various functions such as vomiting, pain, anxiety, and weight loss.

Question 67

What are the receptor subtypes for melatonin, and what is its role?

Answer 67

MT1 and MT2 receptors. Melatonin is involved in regulating sleep and circadian rhythmicity.

Question 68

What are some clinical applications of melatonin agonists?

Answer 68

Melatonin agonists are used for jet lag and insomnia.