Vision 3 Flashcards
What triggers a hyperpolarization in photoreceptor cells, which leads to decreased release of glutamate?
Light
Hyperpolarization in photoreceptors and decreased release of glutamate produces what?
Changes in bipolar membrane potentials, which triggers differential activity in ganglion cells.
Light stimulates rod and cone receptors, which activates which cells?
ON and OFF bipolar and ganglion cells.
What is the relationship of light and glutamate in rods and cones?
light inhibits glutamate release from rods/cones; darkness enhances it
_____ bipolar cells have glutamate receptors that respond to decreased glutamate with depolarization and excitation of the ganglion cell.
ON
Where are ON ganglion cells activated in the presence of light?
In the center of the RF
With darkness in the center of the RF, photoreceptors release more _____.
glutamate
____ bipolar cells have glutamate receptors that respond to increased glutamate with depolarization that excites the ganglion cells.
OFF
With no light, ____ bipolar-ganglion cells are excited.
OFF
WIth no light, _____ bipolar-ganglion cells are inhibited.
ON
There is an (active/inactive) response to darkness in the retina.
active
Each ganglion cell responds to light shining on the center of field _______ to that of peripheral field.
opposite
Which retinal ganglion cells respond to light spots surrounded by dark backgrounds like a star in a dark sky?
On-center retinal ganglion cells
Which retinal ganglion cells respond to dark spots surrounded by light backgrounds like a fly in a bright sky?
Off-center retinal ganglion cells
What CNS concept creates center-surround receptive fields?
Lateral inhibition
