Lecture 11: Synaptogenesis PART TWOOOOOOO

Fovea

Area of highest visual acuity, back of the eye

Optic disk

Area where axons exit the eye; functional blind spot

Optic nerve

Axons bundle and travel to the lateral geniculate

Photoreceptor cell types

Rods and Cones

Cones express 3 types of opsins

S, M, and L

Bipolar cells OFF

AMPAR

Bipolar cells ON

MGluR6

Outer pyriform layer contains

• Photoreceptor axons

• Bipolar dendrites

• Horizontal cell processes

Inner pyriform layer contains

• Bipolar axons

• Retinal ganglion dendrites

• Amacrine processes

What are synapses in rods and cones called?

Ribbon synapses

Synaptic ribbons serve as what?

A storage site of vescles

Timeline of events for Synaptic events in retina

1. Ribbons form into specialization

2. Synaptogenesis of Horizontal cells

3. Synaptogenesis of ON bipolar cells centralling

4. Synaptogenesis of OFF bipolar cells

What is Pickachurin?

A cell adhesion molecule expressed in outer plexiform layer

Pikachurin stabilizes what?

ON bipolar synapses

Pikachurin binds to what?

Dystrophin-glycoprotein complex

Pikachurin increases expression of what?

GPR179

ON bipolar synapses are lost in what KO?

Pikachurin

What happens to horizontal synapses if Pikachurin is knocked out?

Nothing

In Pikachurin KO, what happens to amplitude and time to reach peak?

At all stimuli, it is reduced

What is the CAM associated with rods?

RLFN1

Lrit1/3 CAM for rods or cones?

Cones

ELFN1 co-localizes with what?

MGluR6 for synaptic expression of ON bipolar cells

Electron Microscopy allows us to view what?

Ultra structures

Without ELFN1, what is lost?

Bipolar cells in general

When Rod neurotransmission is lost, what happens?

ELFN1 and mGluR6 are lost

Without calcium, what happens?

EVERYTHING IS FUCKED in synaptic building