08 Cone & Rod Circuits

Question 1

what type of feedback do horizontal cells provide to cones?

Answer 1

negative feedback (inhibitory)

Question 2

bipolar cells are considered on or off cells. what cells communicate if less light is being detected?

Answer 2

off cells

Question 3

29 What type of system is used by retinal ganglion cells to detect light?

Answer 3

centers-surrounds

Question 4

29 What are the three types of signals that can be generated using the centers-surrounds system?

Answer 4

1. On2. Off3. On-Off (intermediate or summation of on and off)

Question 5

30 What type of response would be generated if just the center of the receptive field was stimulated by light?

Answer 5

An “on” response

Question 6

30 What can the centers-surrounds system detect?

Answer 6

Contrast edges (contrast borders)

Question 7

32 What defines the ganglion cell’s contrast sensitivity?

Answer 7

The size of it’s receptive field

Question 8

33 When referring to how ganglion cells respond to stimulus, midget cells are _____ and parasol cells are _______.

Answer 8

tonic, phasic

Question 9

33 What does a tonic response tell the brain?

Answer 9

How big of a change in light stimulus there was

Question 10

33 What does a phasic response tell the brain?

Answer 10

How things (light) are moving around in space (on the retina)

Question 11

what type of bipolar cell uses metabotropic channels?

Answer 11

bipolar on cells

Question 12

do bipolar off cells have metabotropic or ionotropic channels?

Answer 12

ionotropic channels

Question 13

is the on-sublayer closer to the peducle of the cone?

Answer 13

no. the off-sublayer is

Question 14

which type of cell will create a hyperpolarizing signal?

Answer 14

the off cell

Question 15

what type of neurotransmitter do amacrine cells use?

Answer 15

glycine and GABA

Question 16

do rods have a larger synaptic terminal than a cone?

Answer 16

no. rods have a small synaptic terminal compared to cones

Question 17

02 What is the neurotransmitter released from the synaptic terminal?

Answer 17

Glutamate

Question 18

02 Which cells defines if there is a decrease/increase in photons?

Answer 18

Bipolar cells

Question 19

03 Cell begin to _______ as it catches more photons, causes _______ in releasing of glutamate.

Answer 19

hyperpolarize, decrease

Question 20

04 An ______ in photons causes a ______ in glumate release

Answer 20

increase, decrease

Question 21

05 Each cone contacts 100’s of _____ and _____ cells.

Answer 21

bipolar and horizontal cells

Question 22

05 In the synaptic terminal, glutamate binds on ______ and released in vesicle.

Answer 22

synaptic riboon

Question 23

06 Horizontal section of cone pedicle have about 40 ________

Answer 23

synaptic ribbons

Question 24

07 Both sides of each ribbon is flanked by which cells?

Answer 24

horizontal cells.

Question 25

08 What do bipolar cells do?

Answer 25

Complete the triad of connections and also get good information about changes in glutamate released

Question 26

09 In horizontal section of each cone pedicle, processes are packed _____ to each other.

Answer 26

Very densely

Question 27

19 - Which types of cells do rods contact?

Answer 27

Only H1 cells and Rod bipolar cells

Question 28

19 - Each H1 cells contacts about how many rods at a time?

Answer 28

About 700 rods at a time

Question 29

19 - T/F Each rod communicates with at least 2 horizontal cells in order to spread the signal to both sides of the periphery of where thatrod is located.

Answer 29

true

Question 30

20 - T/F All rod bipolar cells are "on-cells".

Answer 30

true

Question 31

21 - What type of amacrine cells connect rods to bipolar cone cells in order to communicate?

Answer 31

all (A2)

Question 32

22 - Because of the sensitivity of rods - they produce a signal that is _________ times stronger than a cone.

Answer 32

100 times

Question 33

24 - What are the four types of ganglion cells?

Answer 33

1) Parasol ganglion cells2) Midget ganglion cells3) Blue-yellow ganglion cells4) Biplexiform ganglion cells

Question 34

24 - 95% of the fovea will contain which type of ganglion cell?

Answer 34

Midget ganglion cells

Question 35

24 - Blue-yellow ganglion cells communicate with which type of cones?

Answer 35

S-cones

Question 36

25 - What does the neural signal depend on?

Answer 36

Changes in firing rate

Question 37

26 - What types of responses do ganglion cells have?

Answer 37

On- and Off- responses