Podcast
Questions and Answers
What role does the vesicle-associated transporter (VAT) play in the transport of ACh?
What role does the vesicle-associated transporter (VAT) play in the transport of ACh?
- It transports ACh from the vesicle to the cytoplasm.
- It facilitates the uptake of ACh from the cytoplasm into vesicles. (correct)
- It converts ACh into inactive metabolites.
- It synthesizes ACh from its precursors.
Which enzyme is responsible for converting Dopa into Dopamine?
Which enzyme is responsible for converting Dopa into Dopamine?
- Dopamine-β-hydroxylase
- Dopa decarboxylase (correct)
- Tyrosine hydroxylase
- Catechol-O-methyltransferase
What triggers the exocytosis of vesicles containing ACh at the nerve terminal?
What triggers the exocytosis of vesicles containing ACh at the nerve terminal?
- The binding of ACh to post-synaptic receptors
- The influx of Ca²⁺ through voltage-gated Ca²⁺ channels (correct)
- The inflow of Na⁺ through sodium channels
- The activation of G-proteins in the presynaptic terminal
What is the process by which Noradrenaline (NA) is synthesized within the vesicle?
What is the process by which Noradrenaline (NA) is synthesized within the vesicle?
What type of carrier is involved in the transport of Tyrosine into the presynaptic nerve terminal?
What type of carrier is involved in the transport of Tyrosine into the presynaptic nerve terminal?
What is the primary enzyme responsible for the synthesis of acetylcholine in the nerve terminal?
What is the primary enzyme responsible for the synthesis of acetylcholine in the nerve terminal?
Which of the following best describes how neurotransmitter action is terminated in the synapse?
Which of the following best describes how neurotransmitter action is terminated in the synapse?
During cholinergic transmission, what is the role of the choline transporter (CHT)?
During cholinergic transmission, what is the role of the choline transporter (CHT)?
Which neurotransmitter is primarily associated with non-adrenergic, non-cholinergic (NANC) signaling in the autonomic nervous system?
Which neurotransmitter is primarily associated with non-adrenergic, non-cholinergic (NANC) signaling in the autonomic nervous system?
Acetylcholine is synthesized from which two main components?
Acetylcholine is synthesized from which two main components?
What step in neurotransmission refers to the process of neurotransmitter release from vesicles into the synapse?
What step in neurotransmission refers to the process of neurotransmitter release from vesicles into the synapse?
Which of the following NANC neurotransmitters is known for playing a role in vasodilation?
Which of the following NANC neurotransmitters is known for playing a role in vasodilation?
Which step in neurotransmission would a drug most likely target to inhibit the release of neurotransmitters?
Which step in neurotransmission would a drug most likely target to inhibit the release of neurotransmitters?
Which mechanism inhibits the breakdown of norepinephrine (NE)?
Which mechanism inhibits the breakdown of norepinephrine (NE)?
Which classes of drugs can prevent the re-uptake of norepinephrine back into presynaptic neurons?
Which classes of drugs can prevent the re-uptake of norepinephrine back into presynaptic neurons?
What best describes a common non-adrenergic, non-cholinergic (NANC) neurotransmitter's role in the autonomic nervous system?
What best describes a common non-adrenergic, non-cholinergic (NANC) neurotransmitter's role in the autonomic nervous system?
Which of the following statements about COMT inhibitors is correct?
Which of the following statements about COMT inhibitors is correct?
What is the primary action of tricyclic antidepressants in relation to norepinephrine?
What is the primary action of tricyclic antidepressants in relation to norepinephrine?
Which of the following neurotransmitters is classified as a non-adrenergic non-cholinergic mediator in the parasympathetic nervous system?
Which of the following neurotransmitters is classified as a non-adrenergic non-cholinergic mediator in the parasympathetic nervous system?
What is the primary effect of hemicholinium on cholinergic neurotransmission?
What is the primary effect of hemicholinium on cholinergic neurotransmission?
Which drug is responsible for blocking the vesicle-associated transporter that affects cholinergic neurotransmission?
Which drug is responsible for blocking the vesicle-associated transporter that affects cholinergic neurotransmission?
Which of the following is NOT a step where drugs can interfere with neurotransmission?
Which of the following is NOT a step where drugs can interfere with neurotransmission?
Which of the following neurotransmitters is specifically mentioned as a co-transmitter in the peripheral nervous system?
Which of the following neurotransmitters is specifically mentioned as a co-transmitter in the peripheral nervous system?
Which neurotransmitter functions primarily in the sympathetic nervous system as a NANC mediator?
Which neurotransmitter functions primarily in the sympathetic nervous system as a NANC mediator?
What is the function of monoamine oxidase (MAO) in neurotransmitter action?
What is the function of monoamine oxidase (MAO) in neurotransmitter action?
Which of the following is a characteristic of non-adrenergic non-cholinergic (NANC) neurotransmitters?
Which of the following is a characteristic of non-adrenergic non-cholinergic (NANC) neurotransmitters?
What is the rate-limiting step in the synthesis of catecholamines?
What is the rate-limiting step in the synthesis of catecholamines?
Which enzyme is responsible for the conversion of Dopa to Dopamine?
Which enzyme is responsible for the conversion of Dopa to Dopamine?
Which statement about the metabolism of catecholamines is correct?
Which statement about the metabolism of catecholamines is correct?
Which metabolite is produced in larger quantities from the oxidative branch of noradrenaline metabolism?
Which metabolite is produced in larger quantities from the oxidative branch of noradrenaline metabolism?
Which enzyme is NOT involved in the metabolism of catecholamines?
Which enzyme is NOT involved in the metabolism of catecholamines?
Which substance can inhibit the rate-limiting step in catecholamine synthesis?
Which substance can inhibit the rate-limiting step in catecholamine synthesis?
What does MHPG sulfate excretion reflect?
What does MHPG sulfate excretion reflect?
Which catecholamine is formed after the enzymatic conversion of noradrenaline?
Which catecholamine is formed after the enzymatic conversion of noradrenaline?
What is the role of the vesicular monoamine transporter (VMAT) in the transmission of adrenergic signals?
What is the role of the vesicular monoamine transporter (VMAT) in the transmission of adrenergic signals?
Which enzyme is directly involved in the conversion of Dopamine to Noradrenaline (NA)?
Which enzyme is directly involved in the conversion of Dopamine to Noradrenaline (NA)?
Which transport mechanism employs a Na⁺ dependent carrier during adrenergic transmission?
Which transport mechanism employs a Na⁺ dependent carrier during adrenergic transmission?
What is the role of choline acetyltransferase (ChAT) in cholinergic transmission?
What is the role of choline acetyltransferase (ChAT) in cholinergic transmission?
In cholinergic transmission, what triggers the release of acetylcholine (ACh) into the synapse?
In cholinergic transmission, what triggers the release of acetylcholine (ACh) into the synapse?
Which of the following components is essential for synthesizing acetylcholine in nerve terminals?
Which of the following components is essential for synthesizing acetylcholine in nerve terminals?
What is produced when Dopa is converted in the process preceding the formation of Noradrenaline?
What is produced when Dopa is converted in the process preceding the formation of Noradrenaline?
How is neurotransmitter action primarily terminated in the synapse?
How is neurotransmitter action primarily terminated in the synapse?
Which of the following neurotransmitters is classified under non-adrenergic, non-cholinergic (NANC) signaling?
Which of the following neurotransmitters is classified under non-adrenergic, non-cholinergic (NANC) signaling?
What is the synthesis process of most neurotransmitters in the peripheral nervous system?
What is the synthesis process of most neurotransmitters in the peripheral nervous system?
Which component is directly involved in neurotransmitter release in response to nerve stimulation?
Which component is directly involved in neurotransmitter release in response to nerve stimulation?
Which statement best reflects the primary mechanism through which drugs exert their effects on neurotransmission?
Which statement best reflects the primary mechanism through which drugs exert their effects on neurotransmission?
Which of the following is the correct sequence of neurotransmitter action from synthesis to termination?
Which of the following is the correct sequence of neurotransmitter action from synthesis to termination?
Which mechanism specifically inhibits the re-uptake of norepinephrine into the presynaptic neuron?
Which mechanism specifically inhibits the re-uptake of norepinephrine into the presynaptic neuron?
What is the primary function of COMT inhibitors in the context of neurotransmitter activity?
What is the primary function of COMT inhibitors in the context of neurotransmitter activity?
Which of the following substances is classified as a non-adrenergic, non-cholinergic (NANC) neurotransmitter?
Which of the following substances is classified as a non-adrenergic, non-cholinergic (NANC) neurotransmitter?
Which neurotransmitter's action is most likely affected by the use of MAO inhibitors?
Which neurotransmitter's action is most likely affected by the use of MAO inhibitors?
Which step in neurotransmission would MOST likely be influenced by the use of cocaine?
Which step in neurotransmission would MOST likely be influenced by the use of cocaine?
Which catecholamine is synthesized immediately after dopamine?
Which catecholamine is synthesized immediately after dopamine?
What is the main urinary metabolite produced from the oxidative metabolism of noradrenaline?
What is the main urinary metabolite produced from the oxidative metabolism of noradrenaline?
Which enzyme is responsible for the production of adrenaline from noradrenaline?
Which enzyme is responsible for the production of adrenaline from noradrenaline?
What effect does metyrosine (α-methyltyrosine) have in the synthesis of catecholamines?
What effect does metyrosine (α-methyltyrosine) have in the synthesis of catecholamines?
Which of the following enzymes primarily contributes to the metabolism of catecholamines through oxidative reactions?
Which of the following enzymes primarily contributes to the metabolism of catecholamines through oxidative reactions?
Which metabolite is associated with the reductive metabolism of noradrenaline?
Which metabolite is associated with the reductive metabolism of noradrenaline?
What overall effect would increased levels of monoamine oxidase (MAO) have on catecholamines?
What overall effect would increased levels of monoamine oxidase (MAO) have on catecholamines?
Which metabolite's excretion reflects the release of noradrenaline in the brain?
Which metabolite's excretion reflects the release of noradrenaline in the brain?
Which neurotransmitter is primarily categorized as a NANC mediator in the sympathetic nervous system?
Which neurotransmitter is primarily categorized as a NANC mediator in the sympathetic nervous system?
What mechanism is primarily targeted when a drug blocks the choline transporter in cholinergic neurotransmission?
What mechanism is primarily targeted when a drug blocks the choline transporter in cholinergic neurotransmission?
Which of the following is NOT considered a major NANC mediator in the autonomic nervous system?
Which of the following is NOT considered a major NANC mediator in the autonomic nervous system?
What effect does vesamicol have on cholinergic neurotransmission?
What effect does vesamicol have on cholinergic neurotransmission?
Which of the following neurotransmitters is involved in vasodilation as a NANC mediator?
Which of the following neurotransmitters is involved in vasodilation as a NANC mediator?
Which step in neurotransmission is directly affected by monoamine oxidase (MAO)?
Which step in neurotransmission is directly affected by monoamine oxidase (MAO)?
Which of the following substances can be considered a co-transmitter in the peripheral nervous system?
Which of the following substances can be considered a co-transmitter in the peripheral nervous system?
In what way can drugs interfere with the storage of neurotransmitters?
In what way can drugs interfere with the storage of neurotransmitters?
What enzyme is responsible for converting Dopamine to Noradrenaline (NA) inside the vesicle?
What enzyme is responsible for converting Dopamine to Noradrenaline (NA) inside the vesicle?
Which component is essential for the transport of Tyrosine into the presynaptic nerve terminal?
Which component is essential for the transport of Tyrosine into the presynaptic nerve terminal?
What function does the vesicular monoamine transporter (VMAT) serve in adrenergic transmission?
What function does the vesicular monoamine transporter (VMAT) serve in adrenergic transmission?
Which two components are produced sequentially during the conversion process of Tyrosine?
Which two components are produced sequentially during the conversion process of Tyrosine?
Which of the following steps is directly influenced by an influx of Ca²⁺ at the nerve terminal?
Which of the following steps is directly influenced by an influx of Ca²⁺ at the nerve terminal?
What is the main precursor for the synthesis of acetylcholine (ACh) in the nerve terminal?
What is the main precursor for the synthesis of acetylcholine (ACh) in the nerve terminal?
Which statement best describes the process of neurotransmitter release in the autonomic nervous system?
Which statement best describes the process of neurotransmitter release in the autonomic nervous system?
What mechanism primarily terminates the action of neurotransmitters in the synapse?
What mechanism primarily terminates the action of neurotransmitters in the synapse?
Which neurotransmitter is synthesized from acetyl-CoA and choline in cholinergic transmission?
Which neurotransmitter is synthesized from acetyl-CoA and choline in cholinergic transmission?
Which NANC neurotransmitter is known for its role in vasodilation?
Which NANC neurotransmitter is known for its role in vasodilation?
What is the function of the choline acetyltransferase (ChAT) enzyme in cholinergic transmission?
What is the function of the choline acetyltransferase (ChAT) enzyme in cholinergic transmission?
What is the role of neuronal reuptake in neurotransmission?
What is the role of neuronal reuptake in neurotransmission?
Which drug class is primarily used to inhibit the re-uptake of norepinephrine back into the presynaptic neuron?
Which drug class is primarily used to inhibit the re-uptake of norepinephrine back into the presynaptic neuron?
Which describes the storage of neurotransmitters within nerve terminals?
Which describes the storage of neurotransmitters within nerve terminals?
What role do COMT inhibitors play in neurotransmitter activity?
What role do COMT inhibitors play in neurotransmitter activity?
Which mechanism is involved in terminating the action of norepinephrine in the synaptic cleft?
Which mechanism is involved in terminating the action of norepinephrine in the synaptic cleft?
Which of the following best describes the role of MAO inhibitors in neurotransmission?
Which of the following best describes the role of MAO inhibitors in neurotransmission?
What is the primary effect of using cocaine in the context of norepinephrine?
What is the primary effect of using cocaine in the context of norepinephrine?
Which neurotransmitter is primarily associated with vasodilation in the parasympathetic nervous system?
Which neurotransmitter is primarily associated with vasodilation in the parasympathetic nervous system?
What step of neurotransmission would be primarily affected by drugs that block vesicle-associated transporters (VAT)?
What step of neurotransmission would be primarily affected by drugs that block vesicle-associated transporters (VAT)?
Which neurotransmitter acts as a co-transmitter in the sympathetic nervous system?
Which neurotransmitter acts as a co-transmitter in the sympathetic nervous system?
Which drug specifically blocks the choline transporter, affecting acetylcholine synthesis?
Which drug specifically blocks the choline transporter, affecting acetylcholine synthesis?
How do nitrogen oxide neurons primarily differ from cholinergic neurons in their signaling?
How do nitrogen oxide neurons primarily differ from cholinergic neurons in their signaling?
Which of the following mediators would most likely be categorized as a non-adrenergic, non-cholinergic (NANC) neurotransmitter involved in mood regulation?
Which of the following mediators would most likely be categorized as a non-adrenergic, non-cholinergic (NANC) neurotransmitter involved in mood regulation?
Which process involves the dissolution of neurotransmitters in the synapse, leading to their eventual breakdown?
Which process involves the dissolution of neurotransmitters in the synapse, leading to their eventual breakdown?
What is the major effect of monoamine oxidase (MAO) in the context of neurotransmitter action?
What is the major effect of monoamine oxidase (MAO) in the context of neurotransmitter action?
What is the function of the enzyme catechol-O-methyltransferase (COMT) in the metabolism of catecholamines?
What is the function of the enzyme catechol-O-methyltransferase (COMT) in the metabolism of catecholamines?
Which of the following statements correctly describes the metabolic pathway of noradrenaline?
Which of the following statements correctly describes the metabolic pathway of noradrenaline?
Which enzyme is involved in the conversion of Dopa to Dopamine?
Which enzyme is involved in the conversion of Dopa to Dopamine?
What effect does metyrosine have on catecholamine synthesis?
What effect does metyrosine have on catecholamine synthesis?
Which of the following metabolites indicates the release of noradrenaline from the brain?
Which of the following metabolites indicates the release of noradrenaline from the brain?
Which step in catecholamine metabolism is catalyzed by monoamine oxidase (MAO)?
Which step in catecholamine metabolism is catalyzed by monoamine oxidase (MAO)?
Which metabolite is primarily produced by the reductive branch of noradrenaline metabolism?
Which metabolite is primarily produced by the reductive branch of noradrenaline metabolism?
What is the outcome of the activity of phenylethanolamine-N-methyltransferase in catecholamine synthesis?
What is the outcome of the activity of phenylethanolamine-N-methyltransferase in catecholamine synthesis?
Study Notes
Neurotransmission in the Autonomic Nervous System (ANS)
- The ANS is responsible for regulating involuntary bodily functions, including heart rate, digestion, and breathing.
- Neurotransmission in the ANS involves the synthesis, storage, release, and termination of neurotransmitters.
- Most neurotransmitters are synthesized in nerve terminals, stored in membrane-bound vesicles, and released into the synapse in response to nerve stimulation.
- Neurotransmitter action is terminated by metabolism or neuronal reuptake.
Cholinergic Transmission
- Acetylcholine (ACh) is the primary neurotransmitter in the parasympathetic nervous system.
- Choline, the precursor for ACh, is transported into the nerve terminal by the choline transporter (CHT).
- ACh is synthesized from acetyl-CoA and choline by the enzyme choline acetyltransferase (ChAT).
- ACh is transported from the cytoplasm into vesicles by a vesicle-associated transporter (VAT).
- Action potentials cause an influx of Ca²⁺ through voltage-gated Ca²⁺ channels, leading to exocytosis of vesicles and release of ACh into the synapse.
Adrenergic Transmission
- Norepinephrine (NA) is the primary neurotransmitter in the sympathetic nervous system.
- Tyrosine is transported into the presynaptic nerve terminal by a Na⁺ dependent carrier.
- Tyrosine is converted to Dopa by the enzyme tyrosine hydroxylase.
- Dopa is converted to Dopamine by the enzyme dopa decarboxylase.
- Dopamine is transported into the vesicle by the vesicular monoamine transporter (VMAT).
- Inside the vesicle, Dopamine is converted to Noradrenaline (NA) by the enzyme dopamine-β-hydroxylase.
Non-Adrenergic Non-Cholinergic (NANC) Mediators
- NANCs include neurotransmitters other than NA and ACh.
- Major NANC mediators in the ANS include:
- Nitric oxide and vasoactive intestinal peptide (VIP) in the parasympathetic NS.
- ATP and neuropeptide Y in the sympathetic NS.
- Others, such as 5-hydroxytryptamine (serotonin), GABA, and dopamine.
Effects of Drugs on Neurotransmission
- Drugs can interfere with neurotransmission at various steps:
- Synthesis of NT
- Storage of NT in vesicles
- Release of NT into the synapse
- Interaction of the NT with post-synaptic receptors
- Termination of NT action
Drug Effects on Cholinergic Neurotransmission
- Hemicholinium blocks the choline transporter, preventing ACh synthesis.
- Vesamicol blocks the vesicle-associated transporter, preventing ACh from entering vesicles.
Drug Effects on Adrenergic Neurotransmission
- Metyrosine inhibits the rate-limiting step of catecholamine synthesis, preventing the conversion of tyrosine to Dopa.
- Reserpine inhibits the vesicular monoamine transporter, blocking NA from accumulating in vesicles.
- Guanethidine prevents the release of NA from the presynaptic neuron.
- COMT-inhibitors (e.g.entacapone) or MAO inhibitors (e.g.selegeline) inhibit the breakdown of NA.
- Tricyclic antidepressants and cocaine can inhibit the reuptake of NA back into the presynaptic neuron.
Neurotransmission in the Autonomic Nervous System
- Neurotransmitters are synthesized in nerve terminals and stored in membrane-bound vesicles.
- Neurotransmitters are released into the synapse in response to nerve stimulation.
- Termination of neurotransmitter action occurs through metabolism or neuronal reuptake.
- Drugs can influence specific steps in neurotransmission.
Cholinergic Transmission
- Choline is transported into the nerve terminal using the choline transporter (CHT).
- Acetylcholine (ACh) is synthesized from acetyl-CoA and choline via the enzyme, choline acetyltransferase(ChAT).
- ACh is transported into vesicles using a vesicle-associated transporter (VAT).
- Influx of Ca²⁺ through voltage-gated Ca²⁺ channels triggers exocytosis of ACh into the synapse.
Adrenergic Transmission
- Tyrosine is transported into the presynaptic nerve terminal using a Na⁺ dependent carrier.
- Tyrosine is converted to Dopa by the enzyme tyrosine hydroxylase.
- Dopa is converted to Dopamine by the enzyme dopa decarboxylase.
- Dopamine is transported into vesicles via the vesicular monoamine transporter (VMAT).
- Inside the vesicle, Dopamine is converted to Noradrenaline (NA) by the enzyme dopamine-β-hydroxylase.
Synthesis of Catecholamines
- Catecholamines are synthesized through a series of enzymatic steps starting with Tyrosine.
- The rate-limiting step in catecholamine synthesis is the conversion of Tyrosine to Dopa, and can be inhibited by metyrosine (α-methyltyrosine).
Metabolism of Catecholamines
- Catecholamines are primarily metabolized by two enzymes: catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO).
Non-Adrenergic Non-Cholinergic (NANC) Mediators
- NANC neurotransmitters are those that are not noradrenaline (NA) or acetylcholine (ACh).
- Major NANC mediators:
- Nitric oxide and vasoactive intestinal peptide (VIP) in the parasympathetic nervous system (PNS).
- ATP and neuropeptide Y in the sympathetic nervous system (SNS).
- Other NANC's include:
- 5-hydroxytryptamine (serotonin)
- GABA
- Dopamine.
Drug Effects on Neurotransmission
- Drugs can interfere with neurotransmission at various steps:
- Synthesis of neurotransmitter
- Storage of neurotransmitter in vesicles
- Release of neurotransmitter into the synapse
- Interaction of the neurotransmitter with post-synaptic receptors
- Termination of neurotransmitter action
Drug Effects on Cholinergic Neurotransmission
- Hemicholinium blocks the choline transporter, preventing ACh synthesis.
- Vesamicol blocks the vesicle-associated transporter (VAT), preventing ACh transport into vesicles.
Drug Effects on Adrenergic Neurotransmission
- Cocaine and tricyclic antidepressants inhibit the re-uptake of NA back into the presynaptic neuron.
- COMT inhibitors (e.g., entacapone) or MAO inhibitors (e.g., selegeline) can inhibit NA breakdown.
Neurotransmission in the Autonomic Nervous System
- The autonomic nervous system uses neurotransmitters to communicate between neurons.
- Neurotransmitters are synthesized in nerve terminals, stored in vesicles, released into the synapse, and then removed from the synapse.
- Drugs can affect each step in neurotransmission.
Cholinergic Transmission
- Choline: Precursor for acetylcholine (ACh) transported into the nerve terminal by the choline transporter (CHT).
- Acetylcholine: Synthesized from acetyl-CoA and choline by the enzyme choline acetyltransferase (ChAT).
- Vesicle-Associated Transporter (VAT): Transports ACh from the cytoplasm into vesicles.
- Nerve stimulation triggers calcium influx, leading to exocytosis of vesicles and ACh release into the synapse.
Adrenergic Transmission
- Tyrosine: Transported into the nerve terminal by a sodium-dependent carrier.
- Tyrosine Hydroxylase: Converts tyrosine to dopa.
- Dopa Decarboxylase: Converts dopa to dopamine.
- Vesicular Monoamine Transporter (VMAT): Transports dopamine into the vesicle.
- Dopamine β-Hydroxylase: Converts dopamine to noradrenaline (NA) within the vesicle.
Catecholamine Synthesis
- Tyrosine is the precursor for catecholamines.
- The rate-limiting step in catecholamine synthesis is the conversion of tyrosine to dopa, which can be inhibited by metyrosine.
- Catecholamines: Dopamine, noradrenaline, adrenaline
Catecholamine Metabolism
- Catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO) are the main enzymes that metabolize catecholamines.
- The primary urinary metabolite of noradrenaline is vanillylmandelic acid (VMA).
Non-Adrenergic Non-Cholinergic (NANC) Mediators:
- NANC neurotransmitters are those other than noradrenaline and acetylcholine.
- NANC mediators in the peripheral nervous system include:
- Parasympathetic: Nitric oxide, vasoactive intestinal peptide (VIP)
- Sympathetic: ATP, neuropeptide Y
- Others: 5-hydroxytryptamine (serotonin), GABA, dopamine
Effects of Drugs on Neurotransmission
- Drugs can interfere with neurotransmission by affecting:
- Neurotransmitter synthesis
- Storage of neurotransmitters in vesicles
- Release of neurotransmitters into the synapse
- Interaction of neurotransmitters with post-synaptic receptors
- Termination of neurotransmitter action
Drug Effects on Cholinergic Neurotransmission
- Hemicholinium: Inhibits choline transport, preventing ACh synthesis.
- Vesamicol: Blocks the VAT, preventing ACh transport into vesicles.
Drug Effects on Adrenergic Neurotransmission
- α-Methyltyrosine (Metyrosine): Inhibits tyrosine hydroxylase, reducing catecholamine synthesis.
- Reserpine: Depletes noradrenaline stores in vesicles.
- Guanethidine: Displaces noradrenaline from vesicles and inhibits release.
- COMT Inhibitors: Inhibit the breakdown of noradrenaline, prolonging its action.
- MAO Inhibitors: Inhibit the breakdown of noradrenaline, prolonging its action.
- Tricyclic Antidepressants, Cocaine: Inhibit the re-uptake of noradrenaline into the presynaptic neuron, prolonging its action.
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Description
Explore the intricate processes of neurotransmission within the autonomic nervous system. This quiz covers the roles of neurotransmitters, focusing on acetylcholine and its synthesis, storage, and action. Test your understanding of how the ANS regulates involuntary bodily functions.
