Neuropharmacology: Serotonin Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary amino acid from which serotonin (5-HT) is synthesized?

Histidine

Tyrosine

Phenylalanine

Tryptophan (correct)

Where is serotonin predominantly stored within the blood?

Red blood cells

Platelets (correct)

Plasma

Lymphocytes

Which enzyme is primarily responsible for the degradation of serotonin?

Aldose reductase

Comt

Monoamine oxidase (MAO) (correct)

Phenylalanine hydroxylase

In what form is serotonin excreted in urine after its metabolism?

5-HIAA Signup and view all the answers

Which stimulus does NOT lead to the release of serotonin from enterochromaffin cells?

Light exposure Signup and view all the answers

Which statement about serotonin's ability to cross the blood-brain barrier (BBB) is accurate?

Serotonin does not cross the BBB. Signup and view all the answers

Which process does NOT involve the action of serotonin?

Neuronal excitation only Signup and view all the answers

What primarily triggers the release of serotonin from serotonergic neurons?

Depolarization and Ca2+ input Signup and view all the answers

Which condition is NOT associated with disturbed serotonin levels?

Hypotension Signup and view all the answers

What is one of the main actions of serotonin in the central nervous system?

Stimulation of appetite control Signup and view all the answers

Which receptor type is primarily implicated in the hallucinogenic effects of drugs like LSD?

5-HT2A Signup and view all the answers

Which of the following statements about SSRIs is TRUE?

SSRIs inhibit serotonin uptake. Signup and view all the answers

In the context of pain transmission, serotonin has which type of effect?

Inhibitory effect on pain transmission Signup and view all the answers

Which of the following drug properties is associated with MDMA?

Increases release of serotonin Signup and view all the answers

Antipsychotic drugs that act on 5-HT2C receptors typically lead to what effect?

Increased appetite and weight gain Signup and view all the answers

Which neurotransmitter is often intertwined with serotonin in the regulation of mood?

Noradrenaline Signup and view all the answers

Which drug is primarily used as an antidepressant and anxiolytic agent?

Fluoxetine Signup and view all the answers

What is the function of 5-HT 3 receptor antagonists like ondansetron?

Serve as antiemetic agents Signup and view all the answers

Which receptor agonists are primarily effective in treating migraines?

5-HT 1B/D/F receptor agonists Signup and view all the answers

Which inflammatory mediator is NOT associated with migraine pathophysiology?

Dopamine Signup and view all the answers

What effect does a reduction in 5-HT levels have in the context of migraines?

Sensitizes pain pathways Signup and view all the answers

Which of the following drugs would be classified as a 5-HT 2 antagonist used for migraines?

Pizotifen Signup and view all the answers

Cortical Spreading Depression is linked to which aspect of migraines?

Aura development Signup and view all the answers

Which of the following describes a complication of the trigemino-vascular system activation in migraines?

Neurogenic inflammation and pain Signup and view all the answers

Which agent is known to inhibit cerebral vasoconstriction during the first phase of a migraine?

5-HT 2 receptor antagonists Signup and view all the answers

What is the primary therapeutic aim during the second phase of a migraine?

Inhibit vasodilation and inflammation Signup and view all the answers

What type of drugs are Pizotifen, Valproate, and Amitriptyline classified as?

Prophylactic agents Signup and view all the answers

Which class of drugs includes Propranolol, Metoprolol, and Timolol, and is considered first-line for migraine prophylaxis?

Beta-blockers Signup and view all the answers

Which of the following compounds is produced by the fungus Claviceps purpurea?

Ergotamine Signup and view all the answers

What is the expected outcome of using NSAIDs like Naproxen and Fenoprofen at the start of a migraine attack?

Provide symptomatic relief Signup and view all the answers

Which of the following is NOT a type of antidepressant used for migraine prophylaxis?

Valproate Signup and view all the answers

What historical condition was caused by consuming grains infected with Claviceps purpurea?

St. Anthony’s Fire Signup and view all the answers

What is one proposed mechanism of action for ergotamine in treating migraines?

Agonism of 5-HT1D receptors leads to vasoconstriction. Signup and view all the answers

Which condition should contraindicate the use of ergotamine?

Coronary artery disease Signup and view all the answers

What serious side effect is associated with methysergide?

Retroperitoneal fibrosis Signup and view all the answers

What is a common adverse reaction of ergotamine?

Nausea and vomiting Signup and view all the answers

Triptans primarily act as agonists for which receptors?

5-HT1B/D/F receptors Signup and view all the answers

Which statement is true regarding the clinical use of methysergide?

It is seldom used due to serious toxicity issues. Signup and view all the answers

Which neuropeptide's release is inhibited by ergotamine through 5-HT1D receptor activation?

CGRP Signup and view all the answers

What is a primary use for triptans in migraine treatment?

Treating acute migraines and cluster headaches. Signup and view all the answers

What is the primary function of triptans in migraine treatment?

To abort acute migraine attacks Signup and view all the answers

Which of the following is a common adverse drug reaction (ADR) associated with triptans?

Dizziness and drowsiness Signup and view all the answers

What is the mechanism of action for lasmiditan?

It is a selective 5HT 1F-receptor agonist Signup and view all the answers

Which class of medications should not be used within 24 hours of triptan administration?

Ergot alkaloids Signup and view all the answers

What is the first line treatment for acute migraine attacks?

Analgesics and NSAIDs Signup and view all the answers

What condition can occur as a serious side effect of combining SSRIs with triptans?

Serotoninergic syndrome Signup and view all the answers

Which of the following drugs is not classified as a triptan?

Ubrogepant Signup and view all the answers

What is a significant benefit of anti-CGRP monoclonal antibodies in migraine treatment?

They inhibit the inflammatory response related to migraine Signup and view all the answers

Study Notes

Pharmacology of Serotonin

Lesson 28
3rd Medicine
Professor: Vittoria Carrabs PhD
Academic year: 2024/25

Index

Introduction
Functional aspects
Clinically used drugs
Drugs used for migraine
Carcinoid syndrome

Introduction

Serotonin (5-HT) is an amine synthesized from the amino acid tryptophan.
Synthesis: Occurs in enterochromaffin cells of the gastrointestinal tract and 5-HT neurons of the central nervous system (CNS).
Location: Highest concentration in the intestinal wall (enterochromaffin cells and myenteric plexus), blood (platelets), and localized regions of the midbrain within the CNS.
Bloodstream transport: 5-HT released by enterochromaffin cells enters the bloodstream, taken up by platelets, and acts on vessel dilation and homeostasis.
Function: Acts as a neurotransmitter and a local hormone in the peripheral vascular system. Its metabolism closely resembles noradrenaline.
Degradation: Primarily through monoamine oxidase (MAO) and excreted in urine.
Blood-Brain Barrier (BBB): 5-HT does not cross the BBB.

Functional aspects

Main Actions: Increased gastrointestinal motility, contraction of other smooth muscles (bronchi, uterus), platelet aggregation, stimulation of nociceptive peripheral nerve endings, and stimulation/inhibition of CNS neurons. Serotonin controls appetite, sleep, mood, hallucinations, behavior, pain perception, and vomiting.
Clinical conditions related to disturbed 5-HT: Migraine, carcinoid syndrome, pulmonary hypertension, mood disorders, and anxiety.
Hallucinogenic Effects: Many hallucinogenic drugs (e.g., LSD) are agonists of 5-HT2A receptors. MDMA ('ecstasy') increases 5-HT release.
Antipsychotic Drugs: Some antipsychotic drugs are antagonists of 5-HT2A receptors (as well as D2 receptors).
Feeding and Appetite: Serotonin induces satiety. Antagonists acting on 5-HT2c receptors associated with several antipsychotic drugs increase appetite and lead to weight gain.
Mood Regulation: Strong evidence suggests 5-HT plays a crucial role in mood regulation alongside norepinephrine.

Sensory Transmission

5-HT exerts an inhibitory effect on transmission in the pain pathway, both in the spinal cord and in the brain.
There's a synergistic effect between 5-HT and analgesics such as morphine.

5-HT Receptors Location

Detailed table listing different 5-HT receptor types, locations, and corresponding main effects. Includes agonist and antagonist drug examples.

Clinically used drugs

5-HT Reuptake Inhibitors: (e.g., fluoxetine) are used to treat depression and anxiety.
5-HT receptor agonists: (e.g., sumatriptan) are used to treat migraine.
5-HT receptor antagonists: (e.g., ondansetron) are used as antiemetics.
Antipsychotic drugs: (e.g., clozapine) efficacy is at least partly related to the action on 5-HT2 receptors.
5-HT4 receptor agonists: (e.g., metoclopramide) can stimulate coordinated peristaltic activity and used to treat gastrointestinal disorders..
Other 5-HT2 antagonists are used to control symptoms of carcinoid tumors.

Migraine Pathophysiology

Chronic Neurological Pathology: Characterized by pulsatile intracranial pain, recurrence, and sensory alterations (photophobia, phonophobia).
Origin of the term: Derived from Ancient Greek "hēmikranía," meaning "pain on one side of the head."
Neurological Dysfunction and Activation of Trigemino-Vascular System: Involves activation, and release of neuropeptides like CGRP causing vasodilation and neurogenic inflammation.
Cortical Spreading Depression: Reduction in neuronal activity spreading across the cortex, linked to aura and causing vascular and inflammatory changes.
Pain Modulation and Neurotransmitters: Pain control mechanisms are altered; reduced 5-HT levels contribute to pain pathway sensitization. Drugs targeting 5-HT1B/D/F receptors are often used.
Genetic, Environmental and Hormonal Factors: Genetic predisposition to migraine triggers from environmental (e.g., stress, diet), and hormonal imbalances (e.g., estrogen affecting onset and duration).
Phases of Migraine: Early phase is characterized by vasoconstriction, later by vasodilation and pain.

Drugs Used for Migraines

Prophylactic Agents: Used in patients with migraine predisposition to prevent attacks (e.g., antihistamines, antiepileptics, antidepressants, beta-blockers, calcium channel blockers).
Acute Attack Treatments: Analgesics (paracetamol, NSAIDs), Triptans (5-HT1B/D/F agonist e.g., sumatriptan, rizatriptan, zolmitriptan, almotriptan), ergotamine, and others like lasmiditan.
Drugs Acting on the CGRP System: (rimegepant, ubrogepant) provide prophylactic and acute relief.
Specific Drugs Methysergide, is a 5-HT2 receptor antagonist used for migraine prophylaxis. Ergot derivatives (ergotamine, dihydroergotamine) are effective for acute migraine treatment.

Carcinoid Syndrome

Rare Disorder: Associated with malignant tumors of enterochromaffin cells, frequently originating in the small intestine and metastasizing to the liver.
Chemical Mediators: Tumors release various chemical mediators, including 5-HT, substance P, and others.
Symptoms: Flushing, abdominal cramps, diarrhea, bronchoconstriction, hypotension, dizziness. Severe cases can involve fibrotic stenosis of heart valves leading to cardiac failure.
Diagnosis: Measured by elevated urinary excretion of 5-HT metabolite (5-HIAA).
Treatment: Symptom control with drugs like cyproheptadine (5-HT2 antagonist).

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on serotonin, its synthesis, storage, and degradation in the body. This quiz covers key concepts such as the roles of serotonin in the central nervous system, its interaction with drugs, and conditions associated with serotonin levels. Perfect for students and enthusiasts of neuropharmacology.