Acetylcholine and Neurotransmitter Systems

These flashcards cover key concepts related to acetylcholine, neurotransmitter receptors, synthesis, degradation pathways, and the role of various neurotransmitters in the nervous system.

What is acetylcholine (ACh)?

The first neurotransmitter discovered and the most widespread neurotransmitter in the body.

What is the primary conclusion of Loewi’s experiment with acetylcholine?

A chemical must be released into the fluid following stimulation of the vagus nerve.

What is the role of acetylcholine in synapses?

It is responsible for communication at cholinergic synapses.

How is acetylcholine synthesized?

ACh is synthesized from Acetyl CoA and Choline by the enzyme Choline acetyltransferase (ChAT).

What enzyme degrades acetylcholine in the synapse?

Acetylcholinesterase (AChE) degrades ACh into Acetyl CoA and Choline.

What are the two subtypes of ACh receptors?

Nicotinic ACh receptors (excitatory) and Muscarinic ACh receptors (inhibitory).

What type of receptors are nicotinic ACh receptors?

Ionotropic receptors that produce EPSPs (excitatory postsynaptic potentials).

What happens when ACh binds to a nicotinic receptor?

The ion channel opens, permitting the diffusion of Na+ into the cell, resulting in depolarization.

What type of receptors are muscarinic ACh receptors?

Metabotropic receptors that usually produce IPSPs (inhibitory postsynaptic potentials).

What is the function of agonists and antagonists in neuropharmacology?

Agonists activate receptor function; antagonists block receptor function.

Name an agonist and antagonist for nicotinic ACh receptors.

Agonist: Nicotine; Antagonist: Curare.

What neurotransmitter is derived from tryptophan and is important for mood?

Serotonin.

What neurotransmitter class do catecholamines belong to?

Dopamine, Norepinephrine, and Epinephrine, all synthesized from the precursor tyrosine.

How does norepinephrine affect wakefulness?

Norepinephrine is important for maintaining wakefulness in the brain.

What is the primary function of GABA as a neurotransmitter?

GABA is the major inhibitory neurotransmitter in the brain.

What happens when GABA binds to its receptors?

Cl⁻ rushes into the cell, causing inhibition.

What is synaptic plasticity?

The ability of synapses to strengthen or weaken over time in response to increases or decreases in activity.