L11 - Retina 3 Parallel Pathways Flashcards Preview

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Flashcards in L11 - Retina 3 Parallel Pathways Deck (12):
1

CASE STUDY: Monica
-65 year old
-Saw water splashing in front of her left eye
-Flickering lights
-Grade 3 Melanoma excised 4 years ago

What's her problem?

Melanoma Associated Retinopathy - antibodies produced targeting against ON BP (mGluR6 or TRPM1 channels) and loses ON BP function
-Patient loses B-wave
-Patient treated with oral prednisolone

2

Where does splitting of information occur first?

At the first synapse (Ph->BCs)

3

Two types of GC

M-GC (5-10% of all GC): motion, LARGE receptive fields -> low spatial res
P-GC: colour, visual acuity, small receptive fields -> high spatial res

4

iGluR are excit/inhibit? mGluR6 are excit/inhibit?

iGluR - excit
mGluR6 (only found in retina) - inhibit

5

OFF cells are de/hyperpol by light? What R?

Hyper, AMPA/Kainate

6

ON cells are de/hyperpol by light? What R?

De, mGluR6

7

What is the difference when comparing the synapses of Ph -> BPs and BP->GCs?

BP-> GC ONLY uses iGluRs (NMDA, AMPA, Kainate)

8

What channel is important in ON BP?

TRPM1 (transient receptor potential melanocyte) channel

9

Receptive field of GC has a centre and an antagonistic surround. What does this mean?

Centre of GC does one thing, surround does opposite

10

What creates the "surround" response?

Horizontal cells

11

Why are edges so important to GC?

Red and green GC communicate edges to the brain - they only fire when there are edges present

12

Melanoma Associated Retinopathy

Antibodies produced targeting against ON BP (mGluR6 or TRPM1 channels) and loses ON BP function
-Patient loses B-wave
-Patient treated with oral prednisolone