Retinal Synapses And Retinal Aging

Question 1

Big overview of phototrsnaducrtion

Answer 1

Photo receptions
Biochemical cascade (channel closure)
Electronic spread
Slowing of glutamate

Question 2

Retinal cells and layers

Answer 2

Rods 
Cods 
Horizontal cells 
Bipolar cells 
Amacrine cells 
Retinal ganglion cells

Question 3

What layer is closest to outermost layer of retina

Answer 3

RPE

Question 4

All the cells in the retina are

Answer 4

Neurons

Question 5

A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a NT

Answer 5

Synapse

Question 6

NT in retina

Answer 6

Glutamate

GABA and glycine

Question 7

Excitatory NT in retina

Answer 7

Glutamate

Question 8

Inhibitory NT of retina

Answer 8

GABA and glycine

Question 9

A change in a cells membrane potential that makes it more negative. It is the opposite of a depolarization. It inhibits AP by increasing the stimulus required to move the membrane potential to the AP threshold

Answer 9

Hyperpolarization

Question 10

Change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge insid the cell

Answer 10

Depolarization

Question 11

Light signal transmission

Answer 11

• light evoked signals are transferred onto bipolar and horixaonly cells
• horizaontl cells provide lateral interactions in the OPL
• bipolar cells transfer the light signals into the IPL, onto the amacrine and ganglion cells
• ganglion cells collect the signals of bipolar and machine cells and transmit these signals to the visual centers of the brain

Question 12

NT of the cone pedicle

Answer 12

Glutamate

Question 13

Synaptic terminal of cone

Answer 13

Pedicle

Question 14

When is glutamate high in cones

Answer 14

In darkness

Question 15

When is glutamate rediced in cone

Answer 15

Reduced by light

Question 16

Off cone bipolar cells and horizaontla cells ______ by light

Answer 16

Hyperpolarizaed

Question 17

On cone bipolar cells _____ by light

Answer 17

Depolarized

Question 18

Off cone bipolar cells transfer signals onto ______ ganglion cells

Answer 18

Off

Question 19

On cone bipolar cells transfer signal onto _____ ganglion cells

Answer 19

ON

Question 20

Concomitant with the increase in density, the bipolar cells and ganglion cells dendritic fields become _______ (midget bipolar and midget ganglion cells)

Answer 20

Smaller

Question 21

The optimized VA in central retina required a high ________ and a low ______

Answer 21

Cone density

Cone-RGC ratio

Question 22

One cone connected to a midget bipolar cell connected to a midget ganglion cell

Answer 22

Midget system

Question 23

Synaptic terminal of rods

Answer 23

Spherules

Question 24

NT of rods

Answer 24

Glutamate

Question 25

NT of rods

Answer 25

Glutamate

Question 26

When is glutamate higher in rods

Answer 26

Darkness

Question 27

When is glutamate lowest in rods

Answer 27

Light

Question 28

What are the types of rod bipolar cells

Answer 28

There is only one type, ON rod bipolar cells depolarized by light

Question 29

Tranmission of the rod signal

Answer 29

``` Rods -on rods bipolar (depolarized) -amacrine cells (depolarized) —glutamate: On cone bipolar cells — ```

Question 30

Where do horizaontl cells synapse

Answer 30

Rod spherules and cone pedicle

Question 31

Horizaontl cells to cone pedicle

Answer 31

Modulated by glutamate release by shifts the activation curves of the cone pedicle Ca2+ channels

Question 32

Rod spherules and horizontal cells

Answer 32

- modulate the glutamate release by shifts the activation curves of the rod spherules Ca2+ channels - release of GABA providing inhibition of bipolar cell dendrites

Question 33

Glutamatergic neurons

Answer 33

Rods, cones,bipolar cells and most ganglion cells

Question 34

GABAergic and Glycinergic neurons

Answer 34

Horixaonral cells and most amacrine cells

Question 35

Nerve fibers and aging

Answer 35

Within the optic nerve, they decrease. Optic cup diameter increases

Question 36

ILM and age

Answer 36

Thickens with age, thus fovea reflex become dimmer

Question 37

RPE cells and aging

Answer 37

Total number of RPE cells decrease significantly with age; lipofuscin within RPE cells increases and Drusen increases

Question 38

Retinal atrophy and aging

Answer 38

Increases throughout the retina

Question 39

Tigroid fundus

Answer 39

Age related retinal atrophy Pigmentation in RPE/choroid decreases -visibility of hidden choroidal vessels -common in ocular albinism

Question 40

Reticular degeneration

Answer 40

Age related retinal atrophy: peripheral RPE degeneration

Question 41

Which type of cells plays a role in transmitting cones signal to RGC?

Answer 41

Cone bipolar cells

Question 42

Which types of cells plays a role in transmitting rod signal to RGC?

Answer 42

Rod bipolar cells and amacrine cells

Question 43

What changes does ON bipolar cells have with light

Answer 43

Depolarization

Question 44

What kind of NT do bipolar cells contain?

Answer 44

Glutamate

Question 45

When the center of RGCs receptive field is exposed to light, which type of RGC is stimulated?

Answer 45

On center RGC

Question 46

Which finding is likely related to aging changes in retina

Answer 46

Dimmer fovea reflex