Activation Cycle of Voltage Gated Sodium Channels: Closed, Open, and Inactivated

Voltage gated sodium (Na+) channels are critically important for a variety of neurobiological phenomena, most notably for the Na+ spike action potentials of various neurons. This video discusses the main functional states of voltage gated Na+ channels, focusing on the mechanistic basis for how Na+ channels transition between each state.

[annas]

I just started my research related to voltage-gated channels, when I read papers they do not explain the basics very well. So, I came across your video and find it very useful and explanatory.

[jonahansen]

Fantastic explication, sir! So much more detail is now known compared to what Hodgkin and Huxley presumed when they first studied the action potential. When I learned this stuff it was clear that there was ion selectivity, voltage gating, etc from the dynamics, but having figured out the molecular mechanism blows my mind. I was always puzzled by how ion selectivity and channel rectification could be produced by molecular structures. People like you, William Catterall, and others have figured it out. Amazing...Kudos!

[domingopartida]

Awesome job with this video, very short and concise

[yagmurhaciahmetoglu]

thank you... you explained it better than my professors!! keep going, you will shine!!

[SaraDarvish-hmjf]

Thank you for your content, fully explained, and to the point. Great 👍

[aymanbiology]

Great video.. keep going.. and my greeting from Egypt.

[noradesmecht]

Thank you so much! Very good explanation

[omnia]

greetings from Egypt! keep going that video is amazing !

[篠崎陽一-oh]

Thanks for your great video! I will introduce this to my students.

[yz]

Wow, what a wonderful explanation, thanks Pete!

[My_Channel]

thanks for your great effort; what is the difference between fast inactivation and slow inactivation?

[varisthashaw]

Terminology 2 domains-
a. voltage sensing domain (positively charged amino acids)
b. pore forming domain (outer selectivity filter and inner voltage gate)

3 states
a. closed (resting)
b. open
c. inactivated

Concept: the voltage gated sodium channel once opened, needs some time to repolarise. but we cannot allow it to remain open for such a long time because too much sodium would enter the cell. thus there is a need for the inactivation state to exist in between. this state ensures that too much sodium is not entering the cell.

[samanthawebb]

when a neuron is at rest, what do the voltage-gated sodium channels do?

[emiemiriic]

Thank you for this very helpful video! Quick question: When the inactivation gate "activates" - are sodium ions still getting into the pore cavity (and just not through) or do they stay away from the cavity entirely?

[mohamadtarkhan]

but how the inactivation gate know when should be open and when should be close? why its exacty one mili second?

[paivinmuhammedahmad]

Thnx very usefull but i can’t get one thing (can we say when the sodium gated channel is inactivated the cell is in a hyperpolirazation state of action potential?

[medicostudy]

is this applicable to sodium channels in working myocardium? as anti arrythmic application?

[majazahmad]

Sir, I am understanding this, please correct me where I go wrong.

So closed state is when rmp is there and voltage sensors are attracted inwards and when any stimulus is there, the rmp reverses it's polarity and sensor is attracted outwards and it opens channel and that also leads to relative refractory period right? And when inactivation gate closes that leads to physical absolute refractory period?

And one more question, what happens to sodium channel when there is Restless membrane potential?

[luvisacigarette]

Question: the inactivation gate is essentially the h-gate, correct? And, the m-gate isn't pictured?

Thanks for the fantastic visuals and presentation!

[lifeisdeception]

Allah is the greatest.Every thing is designed so beautifully and for a very defined purpose