Podcast
Questions and Answers
Which of the following neurotransmitters is NOT categorized as a catecholamine?
Which of the following neurotransmitters is NOT categorized as a catecholamine?
What is the primary function of the mesostriatal pathway in the brain?
What is the primary function of the mesostriatal pathway in the brain?
Where does the mesolimbocortical dopamine pathway originate in the brain?
Where does the mesolimbocortical dopamine pathway originate in the brain?
What is the name of the receptor subtype associated with norepinephrine in the CNS?
What is the name of the receptor subtype associated with norepinephrine in the CNS?
Signup and view all the answers
Which of the following is an indoleamine neurotransmitter?
Which of the following is an indoleamine neurotransmitter?
Signup and view all the answers
What is the name of the brain region where the noradrenergic fibers project from?
What is the name of the brain region where the noradrenergic fibers project from?
Signup and view all the answers
Which of the following neurotransmitters is associated with excitotoxicity?
Which of the following neurotransmitters is associated with excitotoxicity?
Signup and view all the answers
Which type of neurotransmitters includes dopamine and serotonin?
Which type of neurotransmitters includes dopamine and serotonin?
Signup and view all the answers
What is a characteristic of neurotransmitters such as dopamine and norepinephrine?
What is a characteristic of neurotransmitters such as dopamine and norepinephrine?
Signup and view all the answers
Which of the following is an example of a monoamine neurotransmitter?
Which of the following is an example of a monoamine neurotransmitter?
Signup and view all the answers
Which neurotransmitter is involved in noradrenergic pathways?
Which neurotransmitter is involved in noradrenergic pathways?
Signup and view all the answers
What is serotonin classified as?
What is serotonin classified as?
Signup and view all the answers
What occurs when a neurotransmitter binds to an ionotropic receptor?
What occurs when a neurotransmitter binds to an ionotropic receptor?
Signup and view all the answers
What type of ligand would bind to a receptor and initiate the opposite effect of the usual transmitter?
What type of ligand would bind to a receptor and initiate the opposite effect of the usual transmitter?
Signup and view all the answers
What is the term for a drug that binds to the same part of the receptor molecule as the endogenous ligand?
What is the term for a drug that binds to the same part of the receptor molecule as the endogenous ligand?
Signup and view all the answers
What type of receptor may either excite or inhibit the target cell?
What type of receptor may either excite or inhibit the target cell?
Signup and view all the answers
What is the term for a substance produced by the brain that binds to a receptor and mimics the effects of another transmitter?
What is the term for a substance produced by the brain that binds to a receptor and mimics the effects of another transmitter?
Signup and view all the answers
What type of ligand binds to modulatory sites that are not part of the receptor complex that normally binds the transmitter?
What type of ligand binds to modulatory sites that are not part of the receptor complex that normally binds the transmitter?
Signup and view all the answers
Study Notes
Monoamine Neurotransmitters
- There are two main classes of monoamine neurotransmitters: Catecholamines and Indoleamines.
- Catecholamines include dopamine, epinephrine, and norepinephrine.
- Indoleamines include melatonin and serotonin.
Dopaminergic Pathways in the Brain
- Dopamine (DA) is found in neurons in the mesostriatal pathway and mesolimbocortical pathway.
- The mesostriatal pathway originates in the midbrain, specifically the substantia nigra, and innervates the striatum.
- This pathway is important in motor control and neuronal loss is a cause of Parkinson's disease.
- The mesolimbocortical DA pathway originates in the midbrain, specifically the ventral tegmental area (VTA), and projects to the limbic system and cortex.
- DA in this pathway is involved in reward, reinforcement, and learning; abnormalities are associated with schizophrenia.
Noradrenergic Pathways in the Brain
- Norepinephrine (NE) is released from two main clusters in the brainstem: Locus coeruleus (pons) and Lateral tegmental system (midbrain).
- NE is also known as noradrenaline, and cells producing it are noradrenergic.
- Noradrenergic fibers from the locus coeruleus project broadly.
- The CNS has four subtypes of NE receptors, all of which are metabotropic.
- NE systems modulate processes including mood, arousal, and sexual behavior.
Criteria for Neurotransmitters
- Chemicals released onto target cells meet the following criteria:
- Substance exists in presynaptic axon terminals.
- Substance is synthesized in presynaptic cells.
- Substance is released when action potentials reach axon terminals.
- Receptors for the substance exist on postsynaptic membrane.
- When experimentally applied, substance produces changes in postsynaptic cells.
- Blocking substance release prevents changes in postsynaptic cell.
Types of Neurotransmitters
- Many chemical neurotransmitters have been identified, including:
- Amine neurotransmitters: acetylcholine, dopamine, serotonin.
- Amino acid neurotransmitters: GABA, glutamate.
- Peptide neurotransmitters (or neuropeptides): short chain amino acids.
- Gas neurotransmitters: soluble gases, including nitric oxide and carbon dioxide.
Synaptic Transmission
- Co-localization, or co-release, occurs when nerve cells contain more than one type of neurotransmitter.
- The most prevalent excitatory neurotransmitters in the brain are glutamate and aspartate.
- Glutamatergic neurotransmission uses AMPA, Kainate, and NMDA receptors.
- Glutamate is associated with excitotoxicity, unlike GABA, which is inhibitory.
- Endogenous ligands are substances that the brain produces.
- Receptors on neurons may change shape (ionotropic receptors) or alter chemical reactions in the target cell (metabotropic receptors).
- A single neurotransmitter may interact with many different receptor subtypes in different parts of the brain.
Agonist and Antagonist Effects
- Ligands may be:
- Agonists: mimic effects of another transmitter.
- Antagonists: bind receptor without activating it.
- Inverse agonists: bind to receptor and initiates opposite effect of usual transmitter.
- Drugs that act as either agonists, antagonists, or inverse agonists are known as competitive ligands.
- Noncompetitive ligands (or neuromodulators) bind to modulatory sites that are not part of the receptor complex that normally binds the transmitter.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the two main classes of monoamine neurotransmitters, catecholamines and indoleamines, and delve into the dopaminergic pathways in the brain, including the mesostriatal pathway.
