Information Flow/Connections In The Retina

1. A smaller receptive field results in higher spatial resolution.

True

False

The smaller the RF the smaller the object that we can see

Explanation

The smaller the RF the smaller the object that we can see

2. Vertical pathways produce RF _____ and lateral pathways produce RF _____.

Surround; center

Center; surround

3. H1 cells ______ info and H2 cells ______ info

Concentrate; multiply

Multiply; concentrate

Multiply; multiply

4. What cell is responsible for the feedback loop in the retina?

Biplexiform cells

Ganglion cells

Interplexiform cells

carries info from amacrine cells back to bipoalars, other amacrine cells, rods/cones. These are the LAST cells in the lateral connection pathway.

Explanation

carries info from amacrine cells back to bipoalars, other amacrine cells, rods/cones. These are the LAST cells in the lateral connection pathway.

5. In an ON CENTER RF, when light is turned on:

The center will produce more action potentials

The surround will produce more action potentials

The center will produce less action potentials

The surround will produce less action potentials

B and c

A and d

When the light is turned off...the center will produce less APs and return to baseline and the surround will produce more APs before returning back to baseline.

Explanation

When the light is turned off...the center will produce less APs and return to baseline and the surround will produce more APs before returning back to baseline.

6. In an OFF CENTER RF, turning on light will result in less action potentials from the center and less action potentials from the surround

True

False

less APs in center; more APs in surround

Explanation

less APs in center; more APs in surround

7. The OPL is divided into 2 sublamina A and B

True

False

IPL is divided into sublamina A and B

Explanation

IPL is divided into sublamina A and B

8. Sublamina A is associated with the ON pathway

True

False

A --> OFF (off BP teminate here)
B--> ON (on BP terminate here)

Explanation

A --> OFF (off BP teminate here)
B--> ON (on BP terminate here)

9. What is the purpose of having several different rod pathways?

More rods so need more pathways

Allow greater response over greater range of light levels

Able to differentiate between different wavelengths better

10. How many types of horizontal cells are there in primate retina?

1

2

3

H1: connects 7 cones with 300-500 RODS
H2: connects 11-14 cones with a few cones

Explanation

H1: connects 7 cones with 300-500 RODS
H2: connects 11-14 cones with a few cones

11. Horizontal cell inhibition of BPs only occurs in the OFF pathway.

True

False

This can occur in both ON and OFF. This discribes the lateral information flow that occurs to inhibit vertical transmission of info to reine the neural signal

Explanation

This can occur in both ON and OFF. This discribes the lateral information flow that occurs to inhibit vertical transmission of info to reine the neural signal

12. Biplexiform cells receive mostly rod input and their function is unknown.

True

False

Gets info from 25 rods and 2-3 cones

Explanation

Gets info from 25 rods and 2-3 cones

13. There are 25 different amacrine cells each with a known visual function

True

False

ONLY the A2 cell has a known function

Explanation

ONLY the A2 cell has a known function

14. The 'best' response we get from a GC (regardless of being an ON or OFF GC) is when:

Stimulate center only

Stimulate surround only

Stimulate entire RF

15. How do Horizontal cells contribute to receptive fields?

Produce the RF center of GCs

Produce the RF surround of GCs

Can produce both the RF center and surround

See picture on bottom of pg. 152
The horizontal cells provide inhibitory signals to the BP cells. In the picture, the 2 horizontal cells are in laterally placed and there's a central BP cell that is getting excitatory inpulses from the photoreceptor. Therefore, light entering the center PR will result in an excited GC and light that hits the peripheral PRs will provide inhibitory info to the BPs and then the GCs. So in the center we are excited by light (=RF center) and surrounding that area we are inhibited by light (=RF surround)

Explanation

See picture on bottom of pg. 152
The horizontal cells provide inhibitory signals to the BP cells. In the picture, the 2 horizontal cells are in laterally placed and there's a central BP cell that is getting excitatory inpulses from the photoreceptor. Therefore, light entering the center PR will result in an excited GC and light that hits the peripheral PRs will provide inhibitory info to the BPs and then the GCs. So in the center we are excited by light (=RF center) and surrounding that area we are inhibited by light (=RF surround)

16. A2 cells mediate ___ vision and contain _____ as a neurotransmitter

Rod; glycine

Rod; glutamate

Cone; glycine

Cone; glutamate

17. What cell is thought to be involved in the changes that occur in the receptive field during dark adaptation.

Biplexiform cells

Ganglion cells

Interplexiform cells

RF center gets larger leader to several consequences (see previous problem)

Explanation

RF center gets larger leader to several consequences (see previous problem)

18. Where are BP cells found?

ONL

ELM

INL

Photoreceptors are found in the ONL

Explanation

Photoreceptors are found in the ONL

19. Midget GCs receive as much input from amacrine cells as they do from BPs

True

False

Amacrine cells connect with BPs, GCs, and other amacrine cells. They can provide direct input to GCs. Half of all info going to GCs goes through amacrine cells

Explanation

Amacrine cells connect with BPs, GCs, and other amacrine cells. They can provide direct input to GCs. Half of all info going to GCs goes through amacrine cells

20. How much of the brain is used to process visual information?

20%

50%

60%

40 different areas that process vision

Explanation

40 different areas that process vision

21. Amacrine cells have long axons which allows them to contact many different BPs

True

False

Amacrine cells do not have axons, they only have dendrites

Explanation

Amacrine cells do not have axons, they only have dendrites

22. Indicate what changes occur in the receptive field during dark adaptation.

Reduced color vision

More sensitive to low light levels

Reduced VA

RF center gets larger

Submit

23. Horizontal cells have cell bodies in the _____ and synapses in the _____.

OPL; INL

INL; IPL

INL; OPL

Amacrine cells have cell bodies in INL and synapses in IPL

Explanation

Amacrine cells have cell bodies in INL and synapses in IPL

24. In the rod pathways, the rod A2 amacrine cell is involved in connections between:

Rod ON BP and cone ON BP

Rod BP and OFF GC

Rod OFF BP and cone OFF BP

A and b

B and c

The rod pathway can also hijack the cone pathway. This is possible because the rods and cones are connected by gap junctions.

Explanation

The rod pathway can also hijack the cone pathway. This is possible because the rods and cones are connected by gap junctions.

25. Sublamina A of the IPL is more ______ or closer to the ___ cells

Distal; GC

Distal; BP

Proximal; GC

Proximal; BP

Sublamina B is more PROXIMAL or closer to the GC cells

Explanation

Sublamina B is more PROXIMAL or closer to the GC cells

26. A biplexiform cell is a bipolar cell that receives info directly from the photoreceptors.

True

False

Biplexiform is a GANGLION CELL that receives direct info from the PRs

Explanation

Biplexiform is a GANGLION CELL that receives direct info from the PRs