You can't possibly understand how the vision system works unless you consider the fact the this isn't about static images. The retina is designed to detect more than just light/dark and edges. It's all about detecting movement and that's all a matter of temporal processing which is left to the brain and I think that deserves a brief mention here.
On center is having mGluR which is activated by low conc. Glutamate where as surrounding zone is having ionic GluR which is sensitive to high conc glutamate ....Less glutamate activates mGluR so more depol. at BPC as well as GC in on-center off-surroundings where as in opposite case when center is dark, more glutamate releases due to Hyperpol. and it acts on Ionic GluR so depolarisation occurs at BPC, GC....leading to Off center on surrounding situation..😊
Thank you for the amazing explanation. I found one mistake about the glutamate receptor on the Off-center bipolar cell. (1:40-1:45) As others have already pointed out, this is not a K+ channel, but a channel for general cations such as Na+. So that when the channel opens, K+ does not flow out, but Na+ flows in, resulting in depolarization. Thank you.
An exceptionally well explained video! I had my difficulties understanding it when it came up in my neuroscience course but now I can finally grasp the meaning! Thank you!!
Side note: OFF center bipolar cell receptors have sodium channels. If they were potassium channels, binding of glutamate would cause hyperpolarization and a lack of glutamate would cause depolarization. But it wouldn’t depolarize when there’s lack of glutamate because it’s an OFF center cell.
They are non NMDA receptors as opposed to metabotropic glutamat receptors on on center that is why binding of glutamat can result in two different outcomes
Sarah the way you explained this slide was amazing, very easy to follow along and you made it much easier to understand. you should keep going with those videos, Especially since 70k views mean that most of us don't really understand this topic and might actually do well on our exams thanks to you! :)
depends, as an opthamologist myself i can tell you there are different types of horizontal cells that secrete different nt, but the effect is inhibition, there are 30 or so amacrine cell types and at least 3 ganglion cell types in humans
I have to know this crap for my Introduction to Psychology uni course. I’m only a freshman undergrad & I’m just so confused lol. This is very advanced biology material... I hope I’ll get the gist of it soon. Pray for me and my fellow confused psych peers 😭
Could you please make a video explaining what that "patch of retina" in the upper left corner "is"? Are ganglion cells really microscopic little circles surrounded by a bigger circle which in turn is surrounded by a patch or retina? I thought that these "circles" were mere abstract representations of the visual field (in a sort of topographic map), as I learned from this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-oBJSG15Nq2E.html
I didn’t know that the bipolar cells contained different receptors; but, now that I’ve learned it from you, everything is way more clear to me. This is the BEST. Thank you
Thanks a lot for your explanation! I also have a question, just to be completely sure: Can we say that we have ON-center-OFF-surround and OFF-center-ON-surround receptive fields in both bipolar cells AND retinal ganglion cells? :)
