Assignment Prompt & Instructions
Please read and respond to at least two of your peers' initial postings. You may want to consider the following questions in your responses to your peers:
– Compare and contrast your initial posting with those of your peers.
– How are they similar or how are they different?
– What information can you add that would help support the responses of your peers?
– Ask your peers a question for clarification about their post.
– What most interests you about their responses?
Please be sure to validate your opinions and ideas with citations and journal based references in APA format.
Reply from Talibah Tyson
**Ion Channels**
The opening of a ligand-gated channel is initiated when a neurotransmitter that binds to a gatekeeper receptor on an ion channel, it causes a confirmatory change in the receptor which will open the ion channel. Ligand-gated ion channels are ion channels that are linked to receptors that regulate their opening and closing (Stahl, 2021.)
The opening of a voltage-sensitive ion channel are done by the voltage charge across the membrane. Ion flow direction is from outside the cell to the inside when either the Voltage sensitive calcium channel, sodium channel, or potassium channel opens to allow the flow of ions to occur (Stahl, 2021.)
**References**
Stahl, S. M. (2021). _Stahl's essential psychopharmacology: Neuroscientific basis and practical applications_ (5th ed.). Cambridge University Press.
### Reply from Erica OQuin
– Differentiate between the opening of a ligand-gated ion channel and a voltage-sensitive ion channel. The principal difference between the opening of a ligand-gated ion channel and a voltage-sensitive ion channel is the way these channels are activated. Ligand-gated ion channels are activated by ligands which are chemical messengers that bind to specified channel receptor sites. Regulation of ligand gating or opening happens by the binding of endogenous, or exogenous, modulators to allosteric sites (Loussouarn and Tarek, 2021). Ligand-gated ion channel synaptic transmission is extremely quick and occurs in the nervous system at the somatic neuromuscular junction. Ligand-gate ion channels have numerous genes encoded in them with the bulk of these receptors being heteromultimers. This results in a diverse class of ligand-gated ion channels. As a result of such a diverse class of ion channels this can yield in a various receptor with different pharmacological and biophysical properties, (Dai G. ,2023).
In contrast, voltage-gate ion channels are identified as transmembrane proteins that usher ions based on the electrochemical gradient. These Voltage-gated channels are opened by voltage and activated by changes in the electrical potential difference across the membrane, (Loussouarn and Tarek, 2021). In some instances, the voltage- gate ion channel is opened depending on the regulation of the ion flux which is modulated by the transmembrane potential. Multiple voltage-dependent channels have been found, and their role are defined depending on the excitable cell types in which they are expressed and their physiological role, (Dai G., 2023). These voltage-gated ion channels are characterized by their conductance, ion selectivity, pharmacology and voltage-sensitivity, (Dai G., 2023).
References:
Loussouarn, G., & Tarek, M. (2021). Editorial: Molecular Mechanisms of Voltage-Gating in Ion Channels. _Frontiers in pharmacology_, _12_, 768153. https://doi.org/10.3389/fphar.2021.768153
Dai G. (2023). Signaling by Ion Channels: Pathways, Dynamics and Channelopathies. _Missouri medicine_, _120_(5), 367–373.