Podcast
Questions and Answers
Which of the following neurotransmitters is NOT a monoamine?
Which of the following neurotransmitters is NOT a monoamine?
Which neurotransmitter is primarily associated with arousal and the "fight or flight" response?
Which neurotransmitter is primarily associated with arousal and the "fight or flight" response?
Which neurotransmitter plays a significant role in mood, cognition, learning, and physiological functions like digestion and vasoconstriction?
Which neurotransmitter plays a significant role in mood, cognition, learning, and physiological functions like digestion and vasoconstriction?
Which neurotransmitter is a metabolite of glutamate?
Which neurotransmitter is a metabolite of glutamate?
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Which neurotransmitter is primarily released by neurons in the substantia nigra?
Which neurotransmitter is primarily released by neurons in the substantia nigra?
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Which neurotransmitter is primarily associated with motivation, reward, mood, cognition, movement, and learning?
Which neurotransmitter is primarily associated with motivation, reward, mood, cognition, movement, and learning?
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Which of the following is NOT a major source of dopamine in the brain?
Which of the following is NOT a major source of dopamine in the brain?
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Which neurotransmitter is considered to be primarily inhibitory?
Which neurotransmitter is considered to be primarily inhibitory?
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Which neurotransmitter is primarily associated with excitatory signaling in the brain?
Which neurotransmitter is primarily associated with excitatory signaling in the brain?
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What is the role of calcium ions (Ca2+) in synaptic transmission?
What is the role of calcium ions (Ca2+) in synaptic transmission?
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What is the primary difference between an EPSP (Excitatory Postsynaptic Potential) and an IPSP (Inhibitory Postsynaptic Potential)?
What is the primary difference between an EPSP (Excitatory Postsynaptic Potential) and an IPSP (Inhibitory Postsynaptic Potential)?
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What happens to neurotransmitters after they are released into the synaptic cleft?
What happens to neurotransmitters after they are released into the synaptic cleft?
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What is the role of the axon hillock in synaptic transmission?
What is the role of the axon hillock in synaptic transmission?
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What is temporal summation?
What is temporal summation?
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What is the significance of the fact that neurotransmitters bind to postsynaptic receptors?
What is the significance of the fact that neurotransmitters bind to postsynaptic receptors?
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How do dendrites contribute to signal integration in a neuron?
How do dendrites contribute to signal integration in a neuron?
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Which area of the brain is associated with the activation of the cortex and facilitation of learning?
Which area of the brain is associated with the activation of the cortex and facilitation of learning?
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What is the key neurotransmitter that is diminished in patients with Alzheimer's Disease?
What is the key neurotransmitter that is diminished in patients with Alzheimer's Disease?
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What type of receptors are found on neurons in autonomic ganglia?
What type of receptors are found on neurons in autonomic ganglia?
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What type of ACh receptor is involved in neuromuscular junctions (NMJ)?
What type of ACh receptor is involved in neuromuscular junctions (NMJ)?
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Which ACh receptor is generally associated with slower, metabotropic signaling?
Which ACh receptor is generally associated with slower, metabotropic signaling?
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Which of the following is NOT a characteristic of nicotinic receptors?
Which of the following is NOT a characteristic of nicotinic receptors?
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What is the effect of acetylcholine at the postganglionic neuron in the sympathetic nervous system?
What is the effect of acetylcholine at the postganglionic neuron in the sympathetic nervous system?
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Which of the following is TRUE regarding the parasympathetic nervous system?
Which of the following is TRUE regarding the parasympathetic nervous system?
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Which of the following is NOT a known function of acetylcholine?
Which of the following is NOT a known function of acetylcholine?
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Which of the following statements about acetylcholine is TRUE?
Which of the following statements about acetylcholine is TRUE?
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Which neurotransmitter has a significant role in keeping the brain under control by inhibiting neuronal activity?
Which neurotransmitter has a significant role in keeping the brain under control by inhibiting neuronal activity?
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Which type of glutamate receptor, when activated, opens a sodium channel, allowing the influx of sodium ions?
Which type of glutamate receptor, when activated, opens a sodium channel, allowing the influx of sodium ions?
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What is the role of Acetylcholinesterase (AChE) in the synaptic cleft?
What is the role of Acetylcholinesterase (AChE) in the synaptic cleft?
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Which neurotransmitter uses both ionotropic and metabotropic receptors?
Which neurotransmitter uses both ionotropic and metabotropic receptors?
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What is the function of glutamate transporters in the synaptic cleft?
What is the function of glutamate transporters in the synaptic cleft?
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Which of these compounds is NOT a monoamine?
Which of these compounds is NOT a monoamine?
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What enzyme removes a carboxyl group (COOH) from a molecule?
What enzyme removes a carboxyl group (COOH) from a molecule?
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Which of these neurotransmitters is synthesised from dopamine?
Which of these neurotransmitters is synthesised from dopamine?
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What is a varicosity?
What is a varicosity?
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Which of these areas is NOT where norepinephrine is released?
Which of these areas is NOT where norepinephrine is released?
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Which of these statements is TRUE about norepinephrine receptors?
Which of these statements is TRUE about norepinephrine receptors?
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Which of the following is NOT a function of serotonin?
Which of the following is NOT a function of serotonin?
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Which of these statements is FALSE about acetylcholine?
Which of these statements is FALSE about acetylcholine?
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Which of these types of receptors are mostly metabotropic?
Which of these types of receptors are mostly metabotropic?
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Which of these neurotransmitters is primarily released from the adrenal glands?
Which of these neurotransmitters is primarily released from the adrenal glands?
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Study Notes
Neurotransmitters
- Neurotransmitters are endogenous substances that exist in presynaptic axon terminals.
- These substances are synthesized in presynaptic terminals.
- Neurotransmitters are released when action potentials reach the terminal.
- They're recognized by specific receptors on the postsynaptic membrane.
- Application of neurotransmitters alters the postsynaptic cell.
- Blocking their release prevents presynaptic activity.
Types of Neurotransmitters
- Small molecule neurotransmitters: Amines (e.g., dopamine, norepinephrine, serotonin), amino acids (e.g., glutamate, GABA, glycine), acetylcholine.
- Neuropeptides (e.g., endorphins, enkephalins, substance P).
- Gases (e.g., nitric oxide).
Neurotransmitter Synthesis
- Enzymes within the presynaptic terminal synthesize neurotransmitters.
- Rate limiting steps (often an enzyme) control the rate of synthesis.
Neurotransmitter Storage
- Small molecules are stored in synaptic vesicles.
- Large molecules (peptides) are created in the soma and transported to terminals via microtubules (axonal transport).
Neurotransmitter Release
- Action potentials trigger the opening of voltage-gated calcium channels.
- Calcium influx causes synaptic vesicles to fuse with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft.
Neurotransmitter Receptors
- Multiple types of receptors exist for each neurotransmitter.
- Different receptors can determine if the neurotransmitter is excitatory or inhibitory.
- Receptors can be ionotropic (e.g., AMPA, NMDA, GABA-A) or metabotropic (e.g., muscarinic, dopamine, serotonin).
Neurotransmitter Removal
- Neurotransmitters are cleared from the synapse through:
- Reuptake by transporters
- Degradation by enzymes
- Diffusion away from the synapse.
Specific Neurotransmitters
Dopamine (DA)
- Involved in motor control, reward, reinforcement, and learning.
- Loss of dopamine neurons is linked to Parkinson's disease.
- Dopamine pathways include mesostriatal and mesolimbocortical pathways.
- Related to reward-seeking behaviors (e.g., drug use, food, sex).
- Dopamine receptors are metabotropic, with different subtypes (e.g., D1, D2) having varying effects.
- Dopamine removal involves dopamine transporters and monoamine oxidase.
Norepinephrine (NE)
- Released from the locus coeruleus (pons and lateral tegmental system).
- Plays a role in arousal, vigilance, attention, and mood.
- Used as a hormone in the blood to increase heart rate and blood vessel constriction.
- Released predominantly from axonal varicosities allowing for widespread effects.
- Norepinephrine receptors are metabotropic (e.g., α1, α2, β1, β2).
Serotonin (5-HT)
- Located in the raphe nuclei (brainstem)
- Plays a role in sleep-wake cycles, mood, appetite, and pain.
- Involved in sexual behavior and regulation of nausea and vomiting
- Has 14 different receptors
- Removal by reuptake.
Acetylcholine(ACh)
- First recognized neurotransmitter
- Crucial for skeletal muscle contraction (neuromuscular junction).
- Important in the autonomic nervous system (parasympathetic and sympathetic).
- Involved in memory and learning.
- Nicotinic and muscarinic are two important types of acetylcholine receptor
- Removed in the cleft rapidly (50 % of choline recycling in synaptic cleft).
Gamma-aminobutyric acid (GABA)
- Primary inhibitory neurotransmitter in the central nervous system.
- Influencing neuronal excitability.
- GABA receptors: GABAA, GABAB, GABAC, vary in their signaling mechanisms and impact
- Removal from synapse by transporters (or through degradation by GABA-aminotransferase).
Glycine
- Inhibitory neurotransmitter that controls chloride channels.
- Involved in rapid and long-lasting inhibitory effects often with GABA.
Nitric oxide (NO)
- Diffuses out of the cell and into other neurons.
- Involved in retrograde signaling (in which the postsynaptic neuron signals back to the presynaptic).
- Important in synaptic plasticity.
- Vasodilator.
Neuropeptides
- Short chains of amino acids.
- They have diverse roles, from pain relief to social bonding.
- Often involved in modulatory roles rather than direct excitation or inhibition.
- Includes endorphins and other related peptides involved in stress response and pleasure/pain
Other Relevant Information
- Multiple types of neurotransmitters can interact with several types of receptors.
- Co-localization, coexistence and co-release of neurotransmitters in the same neuron is possible.
- Some neurotransmitters act as hormones as well.
- Many drugs target neurotransmitters and their receptors.
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Description
Test your knowledge on neurotransmitters and their roles in the brain with this quiz. Explore various aspects including monoamines, excitatory and inhibitory signaling, and the physiological functions they serve. Perfect for psychology students and enthusiasts!
