Cholinergic Transmission
Cholinergic Transmission - Related Videos
18:01
Paradigms for Pharmacological Characterization of C. elegans Synaptic Transmission Mutants
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Cited by 20 •
2008
This video demonstrates how to employ two neural stimulants, aldicarb and pentylenetetrazole (PTZ), in complementary ways to study synaptic function in the nematode, C. elegans. This complementary approach may also be used to shed light on evolutionarily conserved mechanisms for modulating neuronal synchrony and has implications for epilepsy and seizures.
01:26
Cholinergic Antagonists: Therapeutic Uses
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2023
Antimuscarinic drugs have various therapeutic applications by inhibiting parasympathetic stimulation in different systems. Here are the key therapeutic uses of antimuscarinics: Respiratory Tract: Ipratropium, aclidinium, and tiotropium treat asthma, chronic bronchitis, and chronic obstructive pulmonary disease (COPD). They protect against bronchoconstriction caused by irritants like cigarette smoke, sulfur dioxide, and ozone. They also help reduce nasopharyngeal secretions in common...
01:23
Cholinergic Neurons: Neurotransmission
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2023
Cholinergic neurotransmission involves the synthesis and the release of acetylcholine (ACh) in order to transmit nerve impulses across the synapse. The process begins with the synthesis of acetyl CoA, a precursor for ACh, from ATP, acetate, and coenzyme A in the mitochondria. Choline, another vital precursor, is transported inside the neuron through choline transporters, including high-affinity choline transporter CHT1, low-affinity choline transporter CTL1, and lower-affinity choline...
01:25
Cholinergic Receptors: Muscarinic
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2023
The pharmacological actions of acetylcholine are elicited via its binding to two families of cholinergic receptors or cholinoceptors, namely, muscarinic and nicotinic receptors. Muscarinic receptors are G protein-coupled receptors and have five subtypes, M1–M5. All mAChR subtypes are activated by acetylcholine and blocked by the antagonist, atropine. The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+. Activation...
01:15
Cholinergic Receptors: Nicotinic
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2023
Nicotinic receptors are ligand-gated ion channels that are activated by acetylcholine and nicotine. Upon activation, they cause a rapid increase in the permeability of cells to K+, Na+, and Ca2+, followed by depolarization and excitation. They are in the autonomic ganglia, skeletal neuromuscular junction, CNS, and adrenal medulla. There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
FAQs
Nicotinic receptors form ion channels that produce rapid changes in cellular electrical activity, whereas muscarinic receptors are G protein-coupled receptors that generate slower responses. This distinction allows acetylcholine to support both fast signaling, such as communication related to muscle control, and more gradual regulation in nervous system pathways and organs.
Calcium influx links the arriving action potential to neurotransmitter release. When an action potential reaches the presynaptic terminal, calcium enters the terminal and triggers acetylcholine release into the synaptic cleft. Without this coupling step, the electrical signal would not be efficiently converted into chemical communication between cells.
Acetylcholinesterase terminates cholinergic signaling by rapidly breaking down acetylcholine after it has been released. This prevents the neurotransmitter from continuing to activate receptors indefinitely and helps preserve the timing and precision of cell-to-cell communication. Its activity is therefore important for controlling how long a response persists.
Cholinergic transmission operates at neuromuscular junctions and throughout the autonomic and central nervous systems. Its effects therefore extend beyond muscle control to organ regulation and brain functions such as attention and memory. Examining these locations helps connect one signaling mechanism with movement, internal organ function, and cognitive activity.
The pathway provides important targets for studying neurological disorders and developing therapeutic drugs. Researchers can focus on receptor-mediated responses, acetylcholine release, or signal termination by acetylcholinesterase. These components connect molecular communication with broader nervous system functions, making cholinergic signaling useful for investigating altered neural activity and potential interventions.
Changes in cholinergic signaling can influence movement, attention, memory, and organ function because the pathway operates across neuromuscular, autonomic, and central nervous system settings. The outcome depends on where the communication occurs and which receptor type responds. This broad distribution explains why cholinergic mechanisms are relevant to both neural and muscular physiology.