@@Ashik787 Thank you! This part was what confused me: Note that the combination of ON-center and OFF-center ganglion cells is another example of a parallel pathway. They are physiologically distinct (as just described above). They are anatomically distinct: the dendrites branch out in separate sub-layers of the retina and they receive synaptic inputs from different subclasses of bipolar cells. There is complete coverage: ON-center and OFF-center receptive fields each completely cover the visual field. The neural signals originating in the ON- and OFF-center retinal ganglion cells remain segregated in the retina and the LGN, then merge completely in the complex cells in primary visual cortex (V1).
Lool Bruhh you just killed me!! I m dead by the material and also dead by the similarity between our thinking... my exact thought process found in the first comment LMFAO
You're right, this is getting into some highly technical and abstract concepts, and without a good analogy the average college student won't probably get this.
Fantastic explanation about the concept of the receptive field of the RGC - I'd just want to add something in case some people had the same question as I did whilst watching this video: Both photoreceptor cells of the retina (Rods and Cones) utilise ONLY glutamate as a neurotransmitter - which evokes the question: How is it possible that an ON CENTER bipolar cell even exists, because glutamate is EXCITATORY and somehow the ON CENTER bipolar cell reverses the sign of the ON CENTER cone cell, so how such an arrangement possible? So apparently it is because in the retina we have a special type of glutamate receptor which is actually INHIBITORY, and the ON CENTER bipolar cells have these kind of inhibitory glutamate receptors on their synapses - therefore when the ON CENTER cone cell is going to release glutamate on the ON CENTER bipolar cell it is actually going to be an INHIBITORY "message", NOT an excitatory message, which totally goes against the conventional "glutamate is an excitatory neurotransmitter idea" - apparently for this type of arrangement in the retina glutamate can actually act as an inhibitory neurotransmitter because of these specialized INHIBITORY glutamate receptors.
Yes, a little background in one of the teams that was heavily involved in recognizing metabotropic g protein coupled receptor on the synaptic cleft of the teledendron of the peripheral process of the bipolar cell, this GLUM6R in the prescene of GLU will activate the g protein which as of this time it is unknown the cascade effect that eventually ends up blocking the same receptor and preventing cations from flowing into the cell, when there is low amounts of GLU (when the photoreceptor is hyperpolarized) the G protein won't be stimulated and so the receptor will open and allow depolarization to occur (although it's technically not depolarization beacuse all retina cells except Müller and Ganglion cells are so small, photoreceptors 2-3 mircons in diameter, that there is no need for action potentials, only changes in electrotonic voltage will be sufficient to exocytose the neurotransmitters on their respective teledendrons) thus effectively creating a sign reversing synapse
Literally the best explanation of the On Center/ Off Surround and Off Center and OFF surround ever. It even has a animation to help you visualize the process. Please, make more... This was extremely helpful.
Finally I understood most of the mechanism. The explanation is very good and the images are also very well chosen. The visual material made it so much easier to follow the auditive explanation. Thank you
This is a way more complicated explanation than necessary if you’re trying to get a basic understanding. I wanted to link a video on the subject. I’ll keep looking.
One thing the video missed out is that the neurotransmitter used from the presynaptic membrane of the cones to the postsynaptic membrane of the bipolar cells is GABA. GABA is an inhibitory neurotransmitter, hence the less of it being produced the more the bipolar cell will be activated. So when a cone receives light and hyperpolarises (as mentioned in the video) it will decrease the amount of GABA released (as the cone cell cannot propagate the signal to the presynaptic membrane) and hence the bipolar cell will be less inhibited and will fire more. The opposite is true for when there is no light input, the cone cell will be depolarised so an action potential can propagate meaning more GABA will be released by the cell and so more inhibition will occur on the postsynaptic bipolar cell.
Yeah, that Hc behaviour description is really weird. When cells are depolarises HC releases GABA, which in turn inhibits CaV channels preventing Ca2 from flowing in, so that PR achieves resting state. When cell is hyperpolarised it’s releases less GABA, which in turn disinhibits CaV channel, so those black surrounding will depolarise. It’s a self stabilising loop with negative and positive feedback
Am I right in saying that whatever the centre cone receives, it is in fact the opposite in the bipolar cell since it 'reverses the sign' and that it is post-synaptic? (sorry for the wording, still not fully understood) Also, does the type of bipolar cell determine if it is an ON-centre or an OFF-centre? i.e an ON-bipolar cell would be connected to an ON-centre + an OFF-bipolar cell would be connected to an OFF-centre cone Sorry for all the questions but thanks for any help in advance!
"preserving the sign" just means that the bipolar cell reacts to light the same way the photoreceptor in the center field is doing. All photoreceptors will hyperpolarize when light hits. If the center is hyperpolarized, the off center bipolar cell in that field will also hyperpolarize (preserve the sign) while that field's on center bipolar cells will reverse the sign - or depolarize - when light hits the center. The types of receptors present on the bipolar cells determine if it will be an on center or off center cell.
photoreceptors are always hyperpolarized when light hits. For every receptive field (whether it's an on center/off surround field or an off center/on surround field) there are two bipolar cells in space - an off center and an on center. The off centers "preserve" the sign of the photoreceptors in the center part of the field; meaning that if light hits the center, they are also hyperpolarized. An on center bipolar cell will be depolarized when light hits the center; they will be hyperpolarized when light hits the surround. If light is all over the field, then they are receiving both inhibitory and excitatory signals. Does this answer your question? I'm still uncomfortable with it too!
This can't explain off center off surround.Both off center and off surround will excite the horizontal cell and the horizontal cell will inhibit the center cone a lot. And then the bipolor cell will be excited a lot.
0:26 she says that there are only 2 categories which are (off center- on surround) and (on center - off surround) Where did you get off center-off surround?
Punched a wall, watched again and now I understand! But I can't write for my final exam tomorrow with my good hand because it's ****** up. Oh well, looks like I'm failing.
Yeah, I still don't get it...
i love you
Keri Rodriguez 😂
@@Ashik787 bless your soul man. This solved all my problems.
@@Ashik787 Thank you! This part was what confused me:
Note that the combination of ON-center and OFF-center ganglion cells is another example of a parallel pathway. They are physiologically distinct (as just described above). They are anatomically distinct: the dendrites branch out in separate sub-layers of the retina and they receive synaptic inputs from different subclasses of bipolar cells. There is complete coverage: ON-center and OFF-center receptive fields each completely cover the visual field. The neural signals originating in the ON- and OFF-center retinal ganglion cells remain segregated in the retina and the LGN, then merge completely in the complex cells in primary visual cortex (V1).
Lool Bruhh you just killed me!! I m dead by the material and also dead by the similarity between our thinking... my exact thought process found in the first comment LMFAO
Even with a great explanation like this, this shit is still complicated as hell!
You're right, this is getting into some highly technical and abstract concepts, and without a good analogy the average college student won't probably get this.
@@DogeFrom2014 I m that average student you referring to! You knw what's playing in my head rii now... WHY GOD WHY GOD do I GOTTA SUFFER- KENDRICK lol
Fantastic explanation about the concept of the receptive field of the RGC - I'd just want to add something in case some people had the same question as I did whilst watching this video:
Both photoreceptor cells of the retina (Rods and Cones) utilise ONLY glutamate as a neurotransmitter - which evokes the question: How is it possible that an ON CENTER bipolar cell even exists, because glutamate is EXCITATORY and somehow the ON CENTER bipolar cell reverses the sign of the ON CENTER cone cell, so how such an arrangement possible?
So apparently it is because in the retina we have a special type of glutamate receptor which is actually INHIBITORY, and the ON CENTER bipolar cells have these kind of inhibitory glutamate receptors on their synapses - therefore when the ON CENTER cone cell is going to release glutamate on the ON CENTER bipolar cell it is actually going to be an INHIBITORY "message", NOT an excitatory message, which totally goes against the conventional "glutamate is an excitatory neurotransmitter idea" - apparently for this type of arrangement in the retina glutamate can actually act as an inhibitory neurotransmitter because of these specialized INHIBITORY glutamate receptors.
Yes, a little background in one of the teams that was heavily involved in recognizing metabotropic g protein coupled receptor on the synaptic cleft of the teledendron of the peripheral process of the bipolar cell, this GLUM6R in the prescene of GLU will activate the g protein which as of this time it is unknown the cascade effect that eventually ends up blocking the same receptor and preventing cations from flowing into the cell, when there is low amounts of GLU (when the photoreceptor is hyperpolarized) the G protein won't be stimulated and so the receptor will open and allow depolarization to occur (although it's technically not depolarization beacuse all retina cells except Müller and Ganglion cells are so small, photoreceptors 2-3 mircons in diameter, that there is no need for action potentials, only changes in electrotonic voltage will be sufficient to exocytose the neurotransmitters on their respective teledendrons) thus effectively creating a sign reversing synapse
Really great job! It's clear, simple and well put. I was desperate, I didn't understand it, but thanks to you now I do. 👏
Literally the best explanation of the On Center/ Off Surround and Off Center and OFF surround ever. It even has a animation to help you visualize the process. Please, make more... This was extremely helpful.
Finally I understood most of the mechanism. The explanation is very good and the images are also very well chosen. The visual material made it so much easier to follow the auditive explanation. Thank you
god this hurt my brain watching
Finally a clear and straight to the point video. Good work, and thank you
after 2 hours or more of reading notes and books i gave up. I watched this video and managed to understand it, thank you so much
All freaking day..... but there s light in the end amazing
This is a way more complicated explanation than necessary if you’re trying to get a basic understanding. I wanted to link a video on the subject. I’ll keep looking.
my ears & eyes:yeah now I understand
my brain: no you don't
Thank you for making learning fun and describing it in a comprehensive way
This is the first UA-cam video I encountered that is harder to understand than a professor’s lecture 😢
Best explanation of this topic in the internet
much better than textbook or some online lectures
Plz break it down further..I'm lost😲
Thanks! This video is much better than the interpretation presented by my teacher in university LOL
One thing the video missed out is that the neurotransmitter used from the presynaptic membrane of the cones to the postsynaptic membrane of the bipolar cells is GABA. GABA is an inhibitory neurotransmitter, hence the less of it being produced the more the bipolar cell will be activated. So when a cone receives light and hyperpolarises (as mentioned in the video) it will decrease the amount of GABA released (as the cone cell cannot propagate the signal to the presynaptic membrane) and hence the bipolar cell will be less inhibited and will fire more. The opposite is true for when there is no light input, the cone cell will be depolarised so an action potential can propagate meaning more GABA will be released by the cell and so more inhibition will occur on the postsynaptic bipolar cell.
not true, glutamate is always released. On centre has mGlur6 and off centre has Ampa or Kainate
Yeah, that Hc behaviour description is really weird.
When cells are depolarises HC releases GABA, which in turn inhibits CaV channels preventing Ca2 from flowing in, so that PR achieves resting state.
When cell is hyperpolarised it’s releases less GABA, which in turn disinhibits CaV channel, so those black surrounding will depolarise.
It’s a self stabilising loop with negative and positive feedback
Thanks for make a great animation video. Thats make this topic is more clear for me
I ve understood . ..but still needs clarity can anybody suggest me a book which explains this topic better.....
Maybe a stupid question but what does she mean by "preserve the sign of the cone" and "reverse the sign of the cone"?
Am I right in saying that whatever the centre cone receives, it is in fact the opposite in the bipolar cell since it 'reverses the sign' and that it is post-synaptic? (sorry for the wording, still not fully understood)
Also, does the type of bipolar cell determine if it is an ON-centre or an OFF-centre?
i.e an ON-bipolar cell would be connected to an ON-centre + an OFF-bipolar cell would be connected to an OFF-centre cone
Sorry for all the questions but thanks for any help in advance!
"preserving the sign" just means that the bipolar cell reacts to light the same way the photoreceptor in the center field is doing. All photoreceptors will hyperpolarize when light hits. If the center is hyperpolarized, the off center bipolar cell in that field will also hyperpolarize (preserve the sign) while that field's on center bipolar cells will reverse the sign - or depolarize - when light hits the center. The types of receptors present on the bipolar cells determine if it will be an on center or off center cell.
This was GREAT. Thank you very much. The thorough example was so useful.
Even with on center off surround, why is the center hyperporalized?
photoreceptors are always hyperpolarized when light hits. For every receptive field (whether it's an on center/off surround field or an off center/on surround field) there are two bipolar cells in space - an off center and an on center. The off centers "preserve" the sign of the photoreceptors in the center part of the field; meaning that if light hits the center, they are also hyperpolarized. An on center bipolar cell will be depolarized when light hits the center; they will be hyperpolarized when light hits the surround. If light is all over the field, then they are receiving both inhibitory and excitatory signals. Does this answer your question? I'm still uncomfortable with it too!
Please can you give me a good review paper where you got this information from?
I swear i get everything else having to do with light transmition accept for this
Can you please give me an live example of where it comes to use
Thank you so so so much Mam 🥺
Legendary work 🔥❤️❤️❤️❤️❤️❤️
Great video!
Thank you for this. I finally understand it!
Very well explained, many thanks
excellent video!
Well explained...good job.
This was so helpful thank you!!
soooo counterintuitive but great explanation
best explanation ever ... keep on
Thank you!
OMG now my PhD is safe!
Lucky you, I'm just trying to get through a minor
Brillant
So easy to learn
This can't explain off center off surround.Both off center and off surround will excite the horizontal cell and the horizontal cell will inhibit the center cone a lot. And then the bipolor cell will be excited a lot.
0:26 she says that there are only 2 categories which are (off center- on surround) and (on center - off surround)
Where did you get off center-off surround?
good explaining
Thank u sooooo much I finally got it 🥳
thanks for posting !
Wonderful video
Holy hell its amazing
Best explanation!!,
Thank you so much this saved me
I thought off bipolar cells keep cell depolarized
This was SO clear thank you so much!!!
super clear explanation. Thank you !!!!!
Sensational
thank you!
Why tho
You re amazing
wow i get it thank mam
thats good
I'm learnding
👌🏻👌🏻👌🏻
on off on off on off OMG :(((
What da fuck
inte fashtoooor
Her voice is hot.
I'm going to fucking shoot myself
Punched a wall, watched again and now I understand! But I can't write for my final exam tomorrow with my good hand because it's ****** up. Oh well, looks like I'm failing.
this shit dont make sense
nicely explained