Step I Eye Physiology in Kaplan

[kaleerkalut]

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So I remember when I went through the Kaplan videos there was a section that explained all of the eye physiology stuff (i.e. GABA signals and it is reverse with hyperpolarization causing function etc.) but now I can't find it and its freaking me out. Anybody mind helping me out and telling me where it is? Thanks in advance 🙂

 

[Convalaria]

Light -> phosphoisomerization of rhodopsin (later regeneration of rhodopsin due to Vit A) -> formed metarhodopsin II activates Gt -> stimulation of cGMP PDE -> decrease cGMP -> Na channels close -> hyperpolarization -> decrease glutamate (excitory) release -> inhibition of optic nerve bipolar cells relieved -> initiation of signal transduction to cortex

During dark: partial depolarization -> glutamate release -> optic nerve bipolar cells inhibition

 

[kaleerkalut]

Light -> phosphoisomerization of rhodopsin (later regeneration of rhodopsin due to Vit A) -> formed metarhodopsin II activates Gt -> stimulation of cGMP PDE -> decrease cGMP -> Na channels close -> hyperpolarization -> decrease glutamate (excitory) release -> inhibition of optic nerve bipolar cells relieved -> initiation of signal transduction to cortex

During dark: partial depolarization -> glutamate release -> optic nerve bipolar cells inhibition

Thank you so much! Which section is this in the Kaplan videos? Again thanks a ton 😀

 

[Convalaria]

no problem))

I don't have videos, but it is from Kaplan Biochemistry book, section about vitamins)

 

[kaleerkalut]

no problem))

I don't have videos, but it is from Kaplan Biochemistry book, section about vitamins)

Ahhh yes thank you I remember now! 😀

 

[Phloston]

Light -> phosphoisomerization of rhodopsin (later regeneration of rhodopsin due to Vit A) -> formed metarhodopsin II activates Gt -> stimulation of cGMP PDE -> decrease cGMP -> Na channels close -> hyperpolarization -> decrease glutamate (excitory) release -> inhibition of optic nerve bipolar cells relieved -> initiation of signal transduction to cortex

Light -> phosphoisomerization of rhodopsin (later regeneration of rhodopsin due to Vit A) -> formed metarhodopsin II activates Gt -> stimulation of cGMP PDE -> decrease cGMP -> Na channels close -> hyperpolarization -> closure of voltage-gated Ca2+ channels --> glutamate-containing vesicles cannot fuse with plasma membrane (bc they require calcium to do so) --> decrease glutamate (excitory) release -> inhibition of optic nerve bipolar cells relieved -> initiation of signal transduction to cortex