Talk:Sodium channel

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this page is a little problematic because I don't know anything about sodium channels that may exist in cells other than neurons. Plus, this article is mainly just about voltage-gated na channels. If you can help by adding info about other types of na channels, please do. I don't know, should this page be just "voltage-gated na channels"? That would be weird since there'd be no generic na channel page. --Delldot 01:05, 11 October 2005 (UTC)

• I agree with this comment to an extent; this page does focus mostly on voltage-gated Na channels. However, those are arguably the most important type (at least from a medical standpoint), and many of their features are common to the other Na channels (e.g. selectivity). Maybe this should just be stated at some point in the article.--Jfurr1981 01:14, 11 October 2005 (UTC)

• Those of us that work on channels consider "sodium channel" to be equivalent with "voltage-gated sodium channel." You'll note in some of my modifications that I differentiated between Na⁺ channels and those that simply conduct Na⁺ along with other ions such as Ca²⁺. We would refer to this later class as non-selective cation channels (TRP channels are an example of these, I recall). We also don't normally call receptors channels. Yes, ionotropic receptors do conduct ions, but they're considered a different type of protein. I can easily see how this is confusing to those new to the area. --Dpryan 21:29, 24 July 2006 (UTC)

• What about "epithelial sodium channel (ENaC)" which is not voltage-gated and has different molecular structure than voltage-gated sodium channel? ENaC is very important for sodium regulation in our body and related to hypertension. I think this page should move to "volgate-gated sodium channel". Hchoe 02:06, 21 January 2007 (UTC)

• If you polled 100 neuroscientists and asked them to describe what a sodium channel is at least 99 of them would describe the voltage-gated kind and not ENaCs. Having said that, there should be a reference to ENaCs at the top like, "Sodium channel typically refers to voltage-gated sodium channels but can also describe Epithelial sodium channels (ENaC), the latter described in a seperate article". I'll add something like that to the top in a couple days if no one beats me to it. --Dpryan 20:32, 22 January 2007 (UTC)

• I agree with the comment that most neuroscientists think only the voltage-gated sodium channel. But if you polled 100 nephrologists or 100 gastroenenterologists, the answer would be different. Hchoe 07:58, 4 February 2007 (UTC)

As someone just learning this stuff, the inconsistent terminology is a big problem. "Voltage-gated ion channel sodium channels"? That's a mouthful. All of the ion/sodium/voltage-gated adjective use needs to be looked over by someone. --JMD 05:15, 21 February 2006 (UTC)

See the "Ion_channel" subsection 2.1 Diversity and activation. -- Boris 17:48, 21 February 2006 (UTC)

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Note: I've recently made a large overhaul of this page. There are a number of things that should be added however. Firstly, someone should write a more in depth blurb about how gating works (I work on K+ channels so I don't know enough details to do it properly). It would also be beneficial if someone that does Na+ channel structure function experiments could start to write-up what's known about that. Finally, someone needs to add a nice picture of one of the channels. I could probably hack one together but it wouldn't look very good. If someone reading this is good with image creation, I can send to them what the thing should look like and they can create/upload a novel one (to avoid copyright infringement). If I bump into a Na⁺ channel person I'll try and con them writing some additions. --Dpryan 21:29, 24 July 2006 (UTC)

[edit] Move?

Would anyone object to moving this page to Sodium channel? "Sodium ion channel" sounds kind of awkward to me. delldot | talk 20:01, 9 January 2007 (UTC)

I would encourage such a move, we only ever call the things sodium channels anyway. --Dpryan 22:57, 9 January 2007 (UTC)

OK, since no one has objected, I'm gonna go ahead. If there's a problem we can discuss it and possibly move it back. delldot | talk 01:23, 16 January 2007 (UTC)

[edit] Selectivity Filter

It's my understanding that as an ion passes through the selectivity filter its hydration is shedded. However, the text reads something to the effect of "one sodium ion and one water." This doesn't sound right but I could be mistaken. Can anyone add illumination? Insert-Belltower 03:56, 5 February 2007 (UTC)