Retinal processing Flashcards
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What type of polarization in photoreceptor cell decreases glutamate release?
hyperpolarization
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what does the glutamate do to the bipolar cells?
changes their membrane potenatils that trigger activity in ganglion cells
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What to the glutamate receptors in bipolar cells generate paths of?
Both ON and OFF responses
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What would enhance a glutamate release from photoreceptors?
darkenss
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Hyperpolarization would stimulate what response?
Off response or on response depending on the bipolar cell.
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What happens to ON bipolar cell in response to decreased glutamate?
they depolarize with less glutamate and excite ganglion cell
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what is inhibited by light?
Off bipolar cells are inhibited by decreased glutamate and light.
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How does OFF cell respond to darkness?
Depolarization in response to increased glutamate, excitement
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what inhibits on cells?
excess glutamate and light
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is darkness percieved different than black?
yes, darkness is more grey
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What pattern do OFF center reginial ganglial cells resopnd to?
Dark spots in light background
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What pattern does ON center reginal ganglia respond do?
light spots in dark background. Night sky
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What is the pattern of retina in center surrond receptive field
concentric rings where each ring is opposite of the last in terms of ON or OFF
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What do activated horizontal cells do
Afrevers the activity of the receptors in the center.
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What does later inhibition do?
The center receptors inhibit the bipolar and ganglion cells.
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What cells does lateral inhibition affect?
Both ON and OFF responses
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If I shine light in surrounding OFF area what happens?
OFF cells stimulated, Horizontal cells Inhibit ON cells that would normally respond to light in center.
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What does the center-surround fields enable ganglion cells to do?
center-surround alows ganglion cells to encode contrast.
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what indicates amound of contrast bwtween and center parts of receptive field?
rate of ganglion activity indicates contrast
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what can happen because ganglion cells enhanse contrast?
moderatley bright region may appear brighter or darker depending on background to increase contrast
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What responds to edges?
retinal ganglion: center surround receptive fields
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how do ganglion cells respond to specific color?
due to reciprical excitation and inhibition of various cones.
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What would one color response do to ganglion?
Stimulated by one color would and inhibition by others
