Should specify in the beginning that the activation of the Off bipolar cell is in dark situation, because you are switching from light situation to dark situation without much context except the release of glutamate and the background.
Do horizontal cells contribute the opposing signal of both the center cones and surround cones, or only of the surround cones? Additionally, when we are considering an off-center bipolar cell with an off-center and on-surround, we maximize the depolarization of the cell. However, since the horizontal cells contribute the opposing signal to that of the surround, is it reasonable to say that the off-bipolars are maximally excited because of both the higher rate of Glutamate from the off-cones to the off-center bipolars AND from the opposite signal of the more inhibitory surround cones (contributed to by the horizontal cells of the surround)? Your video states that there is lowered inhibition by the horizontal cells in this case, but can that be thought of as increasing the excitability of the center cones?
I have a question, how does photoreceptor decide whether it will be connected to a Bipolar ON or Bipolar OFF type, the video explains the working given either of the connection. Can a photoreceptor be connected to more that one Bipolar cell? Thanks
At least no paper i've read says that horizontal cells only inhibit cones in the center of their receptive field, so this model is incorrect according to what i know. But i can be wrong, not pretending to know it all or trying to be disrespectful
Here's my attempt at this: - if it's an ON-bipolar cell, no light would mean the *center* photoreceptor would release glutamate and the bipolar cell would hyperpolarize because the cation channels would be closed (sending no signal to the ganglion cell); the *surround* photoreceptors would also release glutamate in the dark and the horizontal (interneuron) cells connecting them to the bipolar cell will inhibit their glutamate release, causing the bipolar cell actually to depolarize. So it would be a medium strength signal due to spatial summation. There will be both hyperpolarization of the center and depolarization of the surround. - if it's an OFF-bipolar cell, no light would create the opposite effect - the *center* would depolarize and the *surround* would hyperpolarize, resulting in a medium strength signal.
Light-center means that the center photoreceptor is releasing less glutamate. Light-surround means that the surround photoreceptors are causing less inhibition. So we have less signal, but we also have less inhibition from the horizontal cell. For an ON bipolar cell, this results in a medium rate of firing for the RGC. From this information, you can't determine a discrete number for exactly how much it's firing, but the important part is how you compare it to different situations. Light-center, light-surround will produce less RGC firing than light-center, dark surround (maximum RGC firing). Light-center, light-surround will produce greater RGC firing than dark-center, light-surround (minimum RGC firing). I hope that helps, and have a great day!
Thanks a lot! Does the horizontal cells also release glycine? And do you have a reference for a close-up read on the receptive fields of bipolar cells? :)
Great question! Actually, the mechanism of the synapse from horizontal cells to rods/cones is not very well understood. One hypothesis is that the horizontal cells release GABA onto the photoreceptors (as shown in this video), but some scientists think it happens via ephaptic coupling or Pannexin 1, which is beyond the scope of this video. If you're looking for a good textbook, I'd recommend Principles of Human Physiology, 6th ed. by Cindy Stanfield. Have a great day, and good luck in all your endeavors!
To better understand this subject you need to go back to the research conducted by Hubel and Wiesel during the second half of the 20th Century. That was the foundation that lead to an understanding for the visual system. Their initial paper was published back around 1960 when I was in Jr. High School. I became interested in the subject in the mid to late 1960s and built an "artificial retina" using an IBM 1620 Computer a couple of years later.
I couldn’t get my head around the topic even after 2 hours of reading on it, but this is so much clearer! Thank you sm
did you get what the horizontal does. it makes the same outcome ( in the case of inner light or inner black, souroundig opposite doesn^t it?
Hope I'll have the same experience, I never understood this
This is the best explanation ever!!
If u r still alive, please continue making such videos!! They are of great help
Understood more in this lecture than 2 different 45 minute lectures I've seen
Amazing! And your voice is so calming
Instablaster.
Great job, I didn't understand in my lesson but it's super clear now, thank you
thank you so much!! this was way more helpful than my 2 hour lecture
No words to describe how much this video helped me. Much thanks ❤
Wonderful video, just what I needed before my exam this week! Thank you!
Beating my head around this topic ended with this explanation. Thank you so much!!
At minute 2:32 it said that on on bipolar cell it gets depolarize. But, should it be the opposite? Depolarize on off dipolar cell?
This was a clear and helpful explanation of on and off bipolar cells. Thanks!
Should specify in the beginning that the activation of the Off bipolar cell is in dark situation, because you are switching from light situation to dark situation without much context except the release of glutamate and the background.
finally professional analysis. thank you!
Thank you so much for your precise speaking and the clear illustrations. I subscribed and liked your page.
Such a great explanation. Thanks for make these topic so clear
That was really awesome. Thank You
Thank you very much..had many headaches trying to understand this. Thank you
That's great illustration
Love your explanation. Thank you so much!
Amazing work, thank you !
This was very helpful - thank you!
helo, i thought it was backwards? on depolarizes and OFF hyperpolarizes?
Very helpful and great animation, thank you !!!
Thank you, this made me finally understand this topic
Please can you talk about the Synaptic organisation of the retina
Why is the entirely white image faster than bright center dark surround?
Thank you. you saved my life
😍 thank you. this video is amazing
Good Work, please make a video on the role of calcium channels in retina
Do horizontal cells contribute the opposing signal of both the center cones and surround cones, or only of the surround cones?
Additionally, when we are considering an off-center bipolar cell with an off-center and on-surround, we maximize the depolarization of the cell. However, since the horizontal cells contribute the opposing signal to that of the surround, is it reasonable to say that the off-bipolars are maximally excited because of both the higher rate of Glutamate from the off-cones to the off-center bipolars AND from the opposite signal of the more inhibitory surround cones (contributed to by the horizontal cells of the surround)? Your video states that there is lowered inhibition by the horizontal cells in this case, but can that be thought of as increasing the excitability of the center cones?
This was Amazing Thank you..
I have a question, how does photoreceptor decide whether it will be connected to a Bipolar ON or Bipolar OFF type, the video explains the working given either of the connection. Can a photoreceptor be connected to more that one Bipolar cell? Thanks
Gracias! Thank you!
Ignoring horizontal cells is bad.
Plus i don't think they only release gaba to the center cones, they do it with all cones or rods?
At least no paper i've read says that horizontal cells only inhibit cones in the center of their receptive field, so this model is incorrect according to what i know.
But i can be wrong, not pretending to know it all or trying to be disrespectful
loved this explanation, thank you so much!
So do the surround photoreceptors not synapse onto their own bipolar cells? Only to horizontal cells?
That was well explained, thank you!
Amazing video, love sm your content omg
This helped me , THX ❤❤❤❤❤❤
amazing video
thankyou so much , helped me alot for Neuro
THANK YOU SOOO MUCH !!!!
great video, thank you!!
Great vidéo ! Only one question
What if we had no lights both on the center and the surround?
ahmagh
@@erfanem1164 ??
@@halima2953 bro when theres no light nothing happens what do you mean
@@erfanem1164 I meant the behavior of the 3 types of cells
Here's my attempt at this:
- if it's an ON-bipolar cell, no light would mean the *center* photoreceptor would release glutamate and the bipolar cell would hyperpolarize because the cation channels would be closed (sending no signal to the ganglion cell); the *surround* photoreceptors would also release glutamate in the dark and the horizontal (interneuron) cells connecting them to the bipolar cell will inhibit their glutamate release, causing the bipolar cell actually to depolarize. So it would be a medium strength signal due to spatial summation. There will be both hyperpolarization of the center and depolarization of the surround.
- if it's an OFF-bipolar cell, no light would create the opposite effect - the *center* would depolarize and the *surround* would hyperpolarize, resulting in a medium strength signal.
you are the best! arigatou gozaimasu :)
Great! Thank you :D
I have poor resolution. I can barely diagnose things what could it be?
What are the RGC situations for light center light surround when ON bipolar
Light-center means that the center photoreceptor is releasing less glutamate. Light-surround means that the surround photoreceptors are causing less inhibition. So we have less signal, but we also have less inhibition from the horizontal cell. For an ON bipolar cell, this results in a medium rate of firing for the RGC.
From this information, you can't determine a discrete number for exactly how much it's firing, but the important part is how you compare it to different situations. Light-center, light-surround will produce less RGC firing than light-center, dark surround (maximum RGC firing). Light-center, light-surround will produce greater RGC firing than dark-center, light-surround (minimum RGC firing).
I hope that helps, and have a great day!
its ok with one cone or rod cell but when it comes to multiple its hard to get idea
amazing
amazing thank you
perfect!
Thank u very much
thanks a lot.
Thanks a lot! Does the horizontal cells also release glycine? And do you have a reference for a close-up read on the receptive fields of bipolar cells? :)
Great question! Actually, the mechanism of the synapse from horizontal cells to rods/cones is not very well understood. One hypothesis is that the horizontal cells release GABA onto the photoreceptors (as shown in this video), but some scientists think it happens via ephaptic coupling or Pannexin 1, which is beyond the scope of this video.
If you're looking for a good textbook, I'd recommend Principles of Human Physiology, 6th ed. by Cindy Stanfield. Have a great day, and good luck in all your endeavors!
@@lauraslusser8710 Thank you a whole lot! And likewise to you :D
tysm
To better understand this subject you need to go back to
the research conducted by Hubel and Wiesel during the
second half of the 20th Century. That was the foundation
that lead to an understanding for the visual system.
Their initial paper was published back around 1960 when
I was in Jr. High School. I became interested in the subject
in the mid to late 1960s and built an "artificial retina" using
an IBM 1620 Computer a couple of years later.
no dijo lo que pasa cuando los 3 recciben luz ( CRY)
💝
omg i finally get it
🤍