Term
| ganglion cell receptive field |
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Definition
increases with periphery
tile the retina |
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Term
| specialization of primate fovea |
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Definition
| cone-->midget bipolar-->midget ganglion |
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Term
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Definition
color-blind
wavelength and intensity are completely confounded |
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Term
|
Definition
multiple, independent groups of neurons that extract distinct signals from the environment and convey these signals in parallel to the next stage in the nervous system
-rods vs cones
-On vs Off bipolar cells
-midget (parvocellular projecting) vs parasol (magnocellular projecting) |
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Term
| ganglion cells that project to thalamus |
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Definition
-midget
parasol
color opponent cells |
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Term
|
Definition
| major route for afferents to neocortex (vision, hearing, touch, temp, pain, taste) |
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Term
| layer IV of primary visual cortex |
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Definition
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Term
| central 2 degrees of visual field of fovea |
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Definition
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Term
| central 10 degrees of visual field of fovea |
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Definition
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Term
|
Definition
| project to layer IVa, IVc-B |
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
| projects to subcortical targets |
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Term
|
Definition
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|
Term
| layer 4 (spiny stellate cells) |
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Definition
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Term
|
Definition
| MT cells tuned for direction of motion |
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Term
| MT necessary for motion perception |
|
Definition
| lesion MT increases % correlation, impairing ability to detect motion |
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Term
| MT cells sufficient to explain motion detection |
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Definition
| individual cells are equally sensitive as the animal |
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Term
| basic phototransduction cascade |
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Definition
1. activated rhodopsin
2. activated transducin (G-protein)
3. activated PDE
4. either cGMP or GMP
if 1. channel opens
if 2. channel closes |
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Term
|
Definition
| light strikes, conformational change occurs and results in excited R* |
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Term
|
Definition
| R* reacts with transducin, catalyzes binding of GTP to G alpha subunit, activates G |
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Term
|
Definition
| two G*s bind to inhibitory gamma subunits of PDE to make E* |
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|
Term
| amplification 2 in phototransduction cascade |
|
Definition
| E* catalyzes hydrolysis of cGMP, lowers cG concentration |
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Term
|
Definition
| lowered cG concentration, reduced influx of Na and Ca through channel |
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Term
| difference between Rod and Cone |
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Definition
1. different opsins
2. different spatial densities depending on retinal location
(fovea dense with cones) |
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Term
|
Definition
| narrow and stiff; higher freq |
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Term
|
Definition
| wide and floppy; lower freq |
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|
Term
| amplification in middle ear |
|
Definition
| large tympanic membrane to small oval window |
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