Biochemistry - Neurotransmitters

Calcium influx (Ca2+)

What is the main trigger for synaptic vesicle fusion in neurotransmission?

Synaptobrevin

Name a SNARE protein involved in neurotransmitter release.

Ionotropic receptors

What type of receptor mediates immediate, fast responses?

Metabotropic (G-protein coupled receptors)

Which receptors are responsible for prolonged responses in neurotransmission?

Synaptotagmin

Acts as a Ca²⁺ sensor to facilitate vesicle fusion.

False

T/F: Ionotropic receptors produce long-lasting responses.

True

T/F: Metabotropic receptors work through second messengers.

False

T/F: SNARE proteins help in the reuptake of neurotransmitters.

True

T/F: Excitatory neurotransmitters usually cause depolarization.

False

T/F: GABA binds primarily to metabotropic receptors.

Myasthenia Gravis

What autoimmune disease targets postsynaptic ACh receptors?

Lambert-Eaton Myasthenic Syndrome (LEMS)

Which disease involves antibodies against presynaptic Ca²⁺ channels?

Clostridium botulinum

What type of bacteria produces botulinum toxin?

Synaptobrevin

Which SNARE protein is cleaved by tetanus toxin?

Glycine

What neurotransmitter is affected in tetanus toxin action?

True

T/F: Botulinum toxin prevents neurotransmitter release by cleaving SNARE proteins.

False

T/F: Myasthenia Gravis patients improve with activity.

False

T/F: LEMS commonly affects the postsynaptic membrane.

False

T/F: Tetanus toxin increases inhibitory neurotransmission.

True

T/F: Botulinum toxicity can impair salivary gland function.

Calcium (Ca2+)

What ion influx is critical for neurotransmitter vesicle release?

Sodium (Na+)

Which ion initiates the action potential?

Voltage-gated sodium channels

What kind of channels open during action potential depolarization?

Na+/K+ ATPase pump

What maintains neuronal resting membrane potential?

True

T/F: Neurotransmitters can bind to ionotropic or metabotropic receptors.

False

T/F: Voltage-gated calcium channels are found on the postsynaptic membrane.

False

T/F: The influx of Na⁺ leads to hyperpolarization.

False

T/F: Action potentials travel in both directions.

True

T/F: Metabotropic receptors activate second messengers.

Glutamine

What is the primary excitatory neurotransmitter in the CNS?

GABA

Name the main inhibitory neurotransmitter in the CNS.

Glycine

Which neurotransmitter is synthesized from serine?

Glutamate decarboxylase

What enzyme converts glutamate to GABA?

EAAT (Excitatory Amino Acid Transporter)

What transporter clears glutamate from the synaptic cleft?

True

T/F: GABA is synthesized from glutamate using Vitamin B6.

False

T/F: Glycine metabolism involves complex astrocyte cycling.

True

T/F: Excess glutamate can cause excitotoxicity.

False

T/F: Aspartate is a prototypical inhibitory neurotransmitter.

True

T/F: GABA acts on Cl⁻ channels causing hyperpolarization.

Membrane depolarization (Hyperpolarization)

What event follows the binding of neurotransmitters to ionotropic receptors?

NMDA receptor

What receptor does memantine antagonize?

Perampanel

Which drug blocks AMPA receptors?

Benzodiazepines

What class of drugs acts on GABA-A allosteric sites?

Seizures (Status epilepticus)

What is a common side effect of benzodiazepine withdrawal?

PCP (Phencylcidine)

What recreational drug is an NMDA antagonist?

False

T/F: Rohypnol causes amnesia by enhancing excitatory neurotransmission.

True

T/F: Anticonvulsants may block Na⁺ and Ca²⁺ channels.

False

T/F: Benzodiazepines bind directly to the GABA binding site.

True

T/F: Memantine is used to treat Alzheimer’s disease.

False

T/F: Perampanel promotes glutamate release.

Acetylcholine

Which neurotransmitter initiates memory formation via the hippocampus?

Basal nucleus of Meynert

What brain structure provides ACh to the hippocampus?

Use it or lose it

What is the principle of neural pruning?

Glutamate

Which neurotransmitter enhances synaptic plasticity for learning?

Hippocampus

Which region of the brain is affected early in Alzheimer’s disease?

False

T/F: Glutamate is inhibitory in learning processes.

True

T/F: Acetylcholine from the brainstem helps maintain alertness

False

T/F: Memory formation is independent of synaptic plasticity

True

T/F: Cholinergic deficits are associated with Alzheimer's.

False

T/F: Synaptic pruning strengthens unused connections.

Choline availability

What is the rate-limiting factor in ACh synthesis?

Acetylcholinesterase (AChE)

What enzyme breaks down acetylcholine in the synapse?

Acetyl CoA + choline

What forms acetylcholine in the neuron?

Cholinesterase inhibitors

Which drug class inhibits AChE to treat Alzheimer’s?

Enhance cholinergic activity

Name one effect of low acetylcholinesterase activity.

False

T/F: Acetylcholinesterase increases ACh levels in the synapse.

True

T/F: AChE inhibitors help slow Alzheimer’s progression.

True

T/F: Without free choline, ACh cannot be resynthesized.

False

T/F: ACh is synthesized in astrocytes.

True

T/F: Choline is recycled after ACh degradation.

Histamine

What neurotransmitter promotes wakefulness and shares function with ACh?

Adenosine

What neurotransmitter promotes sleep and suppresses overactivity?

Adenosine

Which neurotransmitter is displaced by caffeine?

Nitric Oxide

Which gas neurotransmitter promotes vasodilation in the ENS?

Interstitial Cells of Cajal

What cells regulate intestinal smooth muscle contraction?

True

T/F: Histamine enhances memory and learning.

False

T/F: Antihistamines improve cognitive performance in the elderly.

False

T/F: Caffeine enhances adenosine’s sedative effects.

False

T/F: NO promotes smooth muscle contraction.

False

T/F: Housekeeper neurotransmitters are regionally restricted in the brain.