Pharmacology of Neurodegenerative Disease Flashcards
Drugs acting on CNS are two types
1 Work on presynaptic neurons:
Affect the synthesis of neurotransmitter
Affect the storage of neurotransmitter
Affect the release of neurotransmitter
Affect the termination of action of
neurotransmitter
2 Work on post synaptic receptors:
Activate the receptors
Blocks the receptors
What is the shared basic function of neurons in both the CNS and ANS?
a) Sensory perception
b) Transmission of information
c) Muscle contraction
d) Hormone secretion
b) Transmission of information
How do neurons in both the CNS and ANS primarily communicate?
a) Electrical impulses only
b) Chemical signals only
c) Both electrical impulses and chemical signals
d) Hormonal signals
c) Both electrical impulses and chemical signals
Differences between CNS and ANS
ANS
1) There are two neurotransmitters
2)less complex
3)Much lesser number of synapsis
4)No inhibitory neurons
CNS
1) There are numerous.
neurotransmitters
2) More complex circuits
3) Much greater number of
synapsis
4)There are networks of
inhibitory neurons constantly
active modulating the rate of
neuronal transmission
Types of neurodegenerative Disease
- Dementia type:
Alzheimer’s disease - Demyelinating disease:
Multiple Sclerosis (MS) - Parkinson Type
Parkinson disease
Other forms of parkinsonism - Motor neuron disease
Amyotrophic lateral Sclerosis
(ALS)
5.Prion disease لم ندرسه
Neurodegenerative disorders those
respond to drug therapy
Parkinson’s disease
Alzhiemer’s Disease
Multiple Sclerosis (MS)
Amyotrophic Lateral Sclerosis (ALS)
Which of the following statements correctly describes the neurotransmitter characteristics of the Central Nervous System (CNS)?
a) The CNS utilizes only two neurotransmitters.
b) The CNS exhibits numerous neurotransmitters.
c) The CNS does not utilize neurotransmitters.
d) The CNS primarily relies on electrical impulses for communication.
b) The CNS exhibits numerous neurotransmitters.
In terms of circuit complexity, which nervous system component displays more intricate circuits?
a) Central Nervous System (CNS)
b) Autonomic Nervous System (ANS)
c) Both CNS and ANS exhibit similar circuit complexity.
d) Neither CNS nor ANS exhibits circuit complexity.
a) Central Nervous System (CNS)
Which nervous system component is characterized by a significantly higher number of synapses?
a) Central Nervous System (CNS)
b) Autonomic Nervous System (ANS)
c) Both CNS and ANS have a similar number of synapses.
d) Neither CNS nor ANS have synapses.
a) Central Nervous System (CNS)
What distinguishes the Central Nervous System (CNS) from the Autonomic Nervous System (ANS) regarding the presence of inhibitory neurons?
a) The CNS has inhibitory neurons, while the ANS does not.
b) The ANS has inhibitory neurons, while the CNS does not.
c) Both CNS and ANS lack inhibitory neurons.
d) Both CNS and ANS have inhibitory neurons, but they function differently.
a) The CNS has inhibitory neurons, while the ANS does not.
Excitatory Postsynaptic Potentials (EPSP) are initiated by the release of neurotransmitters such as:
a) Dopamine and serotonin
b) Glutamate and GABA
c) Acetylcholine and dopamine
d) Glutamate and acetylcholine
d) Glutamate and acetylcholine
During an EPSP, neurotransmitters bind to:
a) Presynaptic receptors
b) Dendritic spines
c) Axon terminals
d) Postsynaptic receptors
d) Postsynaptic receptors
What is the primary effect of an EPSP on the postsynaptic neuron?
a) Hyperpolarization
b) Inhibition of neurotransmitter release
c) Depolarization due to an influx of sodium ions
d) No change in membrane potential
c) Depolarization due to an influx of sodium ions
How does an EPSP affect the membrane potential of the postsynaptic neuron?
a) The membrane potential becomes more negative
b) The membrane potential remains unchanged
c) The membrane potential becomes more positive, moving closer to its firing threshold
d) The membrane potential becomes more positive, moving further away from its firing threshold
c) The membrane potential becomes more positive, moving closer to its firing threshold
Inhibitory Postsynaptic Potentials (IPSP) are initiated by the release of neurotransmitters, such as:
a) Glutamate and acetylcholine
b) Serotonin and dopamine
c) Gamma-aminobutyric acid (GABA) and glycine
d) Norepinephrine and histamine
c) Gamma-aminobutyric acid (GABA) and glycine
During an IPSP, neurotransmitters bind to:
a) Presynaptic receptors
b) Dendritic spines
c) Axon terminals
d) Postsynaptic receptors
d) Postsynaptic receptors
What is the primary effect of an IPSP on the postsynaptic neuron?
a) Depolarization due to an influx of sodium ions
b) Hyperpolarization due to an influx of potassium ions
c) Hyperpolarization due to an efflux of potassium ions and influx of chloride ions
d) No change in membrane potential
c) Hyperpolarization due to an efflux of potassium ions and influx of chloride ions
How does an IPSP affect the membrane potential of the postsynaptic neuron?
a) The membrane potential becomes more positive, moving closer to its firing threshold
b) The membrane potential remains unchanged
c) The membrane potential becomes more negative, moving further away from its firing threshold
d) The membrane potential becomes more negative, moving closer to its firing threshold
c) The membrane potential becomes more negative, moving further away from its firing threshold
What neurotransmitter is primarily released by neurons in the substantia nigra?
a) Serotonin
b) Dopamine
c) Acetylcholine
d) GABA
b) Dopamine
Which term best describes the firing pattern of dopaminergic neurons from the substantia nigra?
a) Phasic
b) Sporadic
c) Tonic
d) Oscillatory
c) Tonic
What is the primary function of the mutual inhibitory pathway between the substantia nigra and neostriatum?
a) Excitation of both areas
b) Inhibition of both areas
c) Excitation of substantia nigra and inhibition of neostriatum
d) Inhibition of substantia nigra and excitation of neostriatum
b) Inhibition of both areas
Which system does the substantia nigra belong to?
a) Limbic system
b) Autonomic nervous system
c) Central nervous system
d) Extrapyramidal system
d) Extrapyramidal system
What role does the nigrostriatal pathway play in motor activity?
a) Excitatory
b) Inhibitory
c) Both excitatory and inhibitory
d) No role in motor activity
b) Inhibitory
What neurotransmitter is primarily released by neostriatum neurons to the substantia nigra?
a) Dopamine
b) Glutamate
c) GABA
d) Serotonin
c) GABA
Dysfunction of the nigrostriatal pathway is associated with which neurological disorder?
a) Alzheimer’s disease
b) Parkinson’s disease
c) Huntington’s disease
d) Multiple sclerosis
b) Parkinson’s disease
Which neurotransmitter deficiency is characteristic of Parkinson’s disease?
a) Dopamine
b) Serotonin
c) Acetylcholine
d) Glutamate
a) Dopamine
What type of neurons originate from the substantia nigra and terminate in the neostriatum?
a) Glutamatergic
b) GABAergic
c) Dopaminergic
d) Serotonergic
c) Dopaminergic
What is the primary cause of Parkinson’s disease?
a) Overproduction of dopamine
b) Destruction of cells in the neostriatum
c) Degeneration of nerve terminals secreting dopamine in the neostriatum
d) Excessive activity of cholinergic neurons in the substantia nigra
c) Degeneration of nerve terminals secreting dopamine in the neostriatum
Destruction of cells in the substantia nigra results in the
degeneration of the nerve terminals that secrete dopamine in
the neostriatum.
How does the diminished inhibitory influence of dopamine in the neostriatum contribute to Parkinson’s disease?
a) It leads to overproduction of acetylcholine
b) It increases the production of dopamine
c) It decreases the production of acetylcholine
d) It has no effect on neurotransmitter levels
a) It leads to overproduction of acetylcholine
the normal inhibitory influence of dopamine on
cholinergic neurons in the neostriatum is significantly
diminished
That results in overproduction, or a relative overactivity, of
acetylcholine by the stimulatory neurons.
What is the primary pharmacological action of antipsychotic drugs that can lead to secondary parkinsonism?
a) Stimulation of dopamine receptors
b) Inhibition of cholinergic receptors
c) Blockade of dopamine receptors
d) Blockade of acetylcholine receptors
c) Blockade of dopamine receptors
What is the term used to describe parkinsonian symptoms induced by antipsychotic drugs such as phenothiazines and haloperidol?
a) Primary parkinsonism
b)c&d
c) Pseudoparkinsonism
d) Drug-induced parkinsonism
b)c&d
Parkinson’s disease primarily affects which aspect of neurological function?
a) Sensory perception
b) Memory formation
c) Muscle movement
d) Language comprehension
c) Muscle movement
What is the typical age group that Parkinson’s disease mostly affects?
a) Under 30 years
b) Between 30 and 45 years
c) Between 45 and 65 years
d) Over 65 years
d) Over 65 years
What is the estimated incidence of Parkinson’s disease in the general population?
a) 1 in 1,000 individuals
b) 1 in 500 individuals
c) 1 in 100 individuals
d) 1 in 50 individuals
c) 1 in 100 individuals
Manifestations of Parkinson’s Disease
“ 4 Ds “
1) Motor Manifistations
Dyskinesia
2) Non Motor Manifistations
Depression
Dementia
Disturbance of Sleep
Dyskinesia of
Parkinson Disease
6”
1 Akinesia
2 Bradykinesia
3 Muscular rigidity
4 Tremors
5 Postural abnormalities
6 Gait abnormalities
What is the primary goal of therapy for Parkinson’s disease?
a) Increasing the number of cholinergic neurons in the neostriatum
b) Inhibiting the release of dopamine in the basal ganglia
c) Antagonizing the excitatory effect of acetylcholine
d) Reducing the number of inhibitory dopaminergic neurons
c) Antagonizing the excitatory effect of acetylcholine
Which neurotransmitter is primarily targeted for restoration in the basal ganglia during Parkinson’s disease therapy?
a) Serotonin
b) Glutamate
c) Dopamine
d) GABA
c) Dopamine
What is the main aim of antagonizing the excitatory effect of acetylcholine in Parkinson’s disease therapy?
a) To increase cholinergic activity
b) To reduce dopamine levels
c) To restore the balance between dopamine and acetylcholine
d) To enhance inhibitory dopaminergic neurons
c) To restore the balance between dopamine and acetylcholine
What neurotransmitter imbalance characterizes Parkinsonism?
A) GABAergic and glutamatergic imbalance
B) Serotonergic and noradrenergic imbalance
C) Cholinergic and dopaminergic imbalance
D) Adrenergic and histaminergic imbalance
C) Cholinergic and dopaminergic imbalance
Strategy of Parkinson Disease
Therapy is aimed at:
1.Restoring dopamine in the basal ganglia.
2. Antagonizing the Cholinergic excitatory effect.
(reestablishing the correct dopamine/acetylcholine balance)
Antiparkinson’s Disease
A) Drugs enhance Dopaminergic
pathway
1) Central Dopamine release enhancers
a) Dopamin Precursors
L.dopa
b)Peripheral decarboxylase inhibitors
Carbidopa
c) COMT inhibitors
Entacapone , Tolcapone
2)Central Dopamine degradation inhibitors
“MAOB inhibitors”
Selegiline , Rasagiline
3) Dopamine Agonist
Bromocriptine
4) Dopamine facilitators **Amantadine , Apomorphine
B) Centrally Acting Anticholinergics
Trihexiphenidyl
Benztropine
Which of the following drugs inhibits the peripheral decarboxylation of levodopa?
A) Selegiline
B) Rasagiline
C) Carbidopa
D) Tolcapone
C) Carbidopa
Trihexyphenidyl and benztropine are examples of:
A) Dopamine precursors
B) Peripheral decarboxylase inhibitors
C) MAOB inhibitors
D) Centrally acting anticholinergics
D) Centrally acting anticholinergics
Levodopa enhances dopamine synthesis in the CNS by:
A) Crossing the blood-brain barrier as dopamine
B) Inhibiting the decarboxylase enzyme
C) Acting as a direct precursor to dopamine
D) Inducing dopamine release from synaptic vesicles
C) Acting as a direct precursor to dopamine
How does levodopa cross the blood-brain barrier?
A) Through passive diffusion
B) Via specific dopamine transporter proteins
C) Using large neutral amino acid transporter (LAT1)
D) By undergoing active transport mediated by COMT
C) Using large neutral amino acid transporter (LAT1)
Which enzyme converts levodopa to dopamine in the CNS?
A) Catechol-O-methyl transferase (COMT)
B) Monoamine oxidase B (MAOB)
C) Dopamine beta-hydroxylase
D)L-amino acid decarboxylase
D)L-amino acid decarboxylase
The main purpose of administering levodopa in Parkinson’s disease is to:
A) Inhibit the breakdown of dopamine
B) Increase the synthesis of serotonin
C) increase the activity of cholinergic neurons
D) Compensate for the deficiency of dopamine in the brain
D) Compensate for the deficiency of dopamine in the brain
Which peripheral enzyme is responsible for the metabolism of levodopa into dopamine?
A) Catechol-O-methyl transferase (COMT)
B) Monoamine oxidase B (MAOB)
C) Dopamine beta-hydroxylase
D) L-amino acid decarboxylase
D) L-amino acid decarboxylase
What is the primary function of levodopa in the treatment of Parkinson’s disease?
A) Inhibition of dopamine degradation
B) Enhancement of dopamine synthesis
C) Blockade of dopamine receptors
D) Inhibition of acetylcholine release
B) Enhancement of dopamine synthesis
Chat gpt
Why can’t dopamine itself effectively cross the blood-brain barrier?
A) It is too large to pass through
B) It is rapidly metabolized in the bloodstream
C) It is actively transported out of the brain
D) It is degraded by enzymes in the blood
A) It is too large to pass through
What is the primary location in the brain where levodopa is converted to dopamine?
A) Substantia nigra
B) Striatum
C) Hippocampus
D) Thalamus
A) Substantia nigra
What is the primary reason for the short half-life of levodopa?
A) Rapid metabolism by catechol-O-methyl transferase (COMT)
B) Inhibition of absorption in the gastrointestinal tract (GIT)
C) High protein binding in the bloodstream
D) Limited ability to cross the blood-brain barrier
A) Rapid metabolism by catechol-O-methyl transferase (COMT)
How does levodopa primarily cross the blood-brain barrier?
A) Passive diffusion
B) Active transport via dopamine transporter proteins
C) Utilization of specific amino acid transporters (LAT1)
D) Conversion to dopamine prior to crossing the barrier
C) Utilization of specific amino acid transporters (LAT1)
Which enzyme metabolizes levodopa into 3-O-Methyldopa in the circulation?
A) Aromatic L-amino acid decarboxylase (AADC)
B) Monoamine oxidase (MAO)
C) Catechol-O-methyl transferase (COMT)
D) Dopamine beta-hydroxylase
C) Catechol-O-methyl transferase (COMT)
Why does the amount of levodopa that reaches the CNS remain limited?
A) Rapid degradation by MAO in the bloodstream
B) Competition at LAT1 by 3-O-Methyldopa
C) Inhibition of absorption in the small intestine
D) High affinity for binding to plasma proteins
B) Competition at LAT1 by 3-O-Methyldopa
How does the extensive metabolism of levodopa in the gastrointestinal tract (GIT) affect its bioavailability?
A) Increases bioavailability due to enhanced absorption
B) Decreases bioavailability due to decreased absorption
C) Does not affect bioavailability as levodopa is not absorbed in the GIT
D) Converts levodopa into dopamine, increasing its bioavailability
B) Decreases bioavailability due to decreased absorption
Which enzyme is primarily responsible for the metabolism of levodopa in the gastrointestinal tract (GIT)?
A) Monoamine oxidase (MAO)
B) Catechol-O-methyl transferase (COMT)
C) decarboxylase
D) Dopamine beta-hydroxylase
C) decarboxylase
Why is levodopa preferably administered on an empty stomach?
A) To minimize gastrointestinal side effects
B) To enhance its absorption from the small intestine
C) To reduce the risk of drug interactions
D) To prevent rapid metabolism by COMT
B) To enhance its absorption from the small intestine
What is the primary metabolic pathway of levodopa in the circulation?
A) Conversion to dopamine by monoamine oxidase (MAO)
B) Metabolism into 3-O-Methyldopa by catechol-O-methyl transferase (COMT)
C) Breakdown into inactive metabolites by aromatic L-amino acid decarboxylase (AADC)
D) Direct excretion unchanged through the kidneys
B) Metabolism into 3-O-Methyldopa by catechol-O-methyl transferase (COMT)
G.R
The amount of levodopa that reaches the CNS is too small?
due to peripheral decarboxylation and competition at LAT1
by 3-O-Methyldopa.
Which of the following side effects is primarily caused by the peripheral metabolism of levodopa leading to an increase in dopamine?
A) Muscle rigidity
B) Dyskinesias
C) Nausea and/or vomiting
D) Depression
C) Nausea and/or vomiting
Stimulation of dopaminergic receptors by dopamine produced from the decarboxylation of levodopa can lead to:
A) Hypertension
B)Hypoglycemia
C) Cardiac arrhythmias
D) Hyperglycemia
C) Cardiac arrhythmias
The peripheral metabolism of levodopa
will cause the increase in dopamine that
will cause the following side effects:
Nausea and/or vomiting
Cardiac arrhythmias
Hypotension
The peripheral metabolism of levodopa can contribute to which of the following cardiovascular side effects?
A) Hypertension
B) Bradycardia
C) Hypotension
D) Peripheral edema
C) Hypotension
Which receptor type is primarily involved in mediating the side effects such as nausea, vomiting, and cardiac arrhythmias caused by the peripheral metabolism of levodopa?
A) Alpha-adrenergic receptors
B) Beta-adrenergic receptors
C) Dopaminergic receptors
D) Serotonergic receptors
C) Dopaminergic receptors
What is the underlying mechanism of the side effects induced by the peripheral metabolism of levodopa?
A) Stimulation of adrenergic receptors
B) Inhibition of acetylcholine release
C) Stimulation of dopaminergic receptors
D) Blockade of glutamatergic neurotransmission
C) Stimulation of dopaminergic receptors
How Can be done to increase the
amount of Levodopa that reaches
the CNS and reduce the side
effects related to overproduction
of Dopamine in peripheral
tissues???
That can be done by preventing
decarboxylation of levodopa by adding
decarboxylase enzyme inhibitor.
(Carbidopa)
Which of the following drugs can be co-administered with levodopa to increase the amount of levodopa that reaches the CNS and reduce the side effects related to the overproduction of dopamine in peripheral tissues?
A) Bromocriptine
B) Selegiline
C) Tolcapone
D) Carbidopa
D) Carbidopa
G.R
Levodopa should always be giving combined with
carbidopa?
The addition of carbidopa lowers the dose of
levodopa needed by four- to five-fold and,
consequently, decreases the severity of adverse
effects arising from peripherally formed dopamine.
Cautions when taking levodopa:
1) To be given on empty stomach (at least 30 minutes before food) (because proteins interferes with its absorption).
On - Off phenomenon: (when given with food it cause
fluctuation in the effect»_space; sudden onset tremors, cramps and loss of ability to move).
2) Should not be stopped suddenly.
Which medication should always be combined with levodopa to enhance its efficacy and reduce the severity of adverse effects arising from peripherally formed dopamine?
A) Bromocriptine
B) Selegiline
C) Tolcapone
D) Carbidopa
D) Carbidopa
What is the primary reason for combining carbidopa with levodopa?
A) To inhibit the peripheral metabolism of levodopa
B) To enhance the central metabolism of levodopa
C) To potentiate the effects of levodopa on dopamine receptors
D) To reduce the risk of gastrointestinal side effects
A) To inhibit the peripheral metabolism of levodopa