Chapter 10 Pt. 2 (Part 3) Flashcards
how does photoreceptor density change going from the fovea to the periphery?
as distance to the fovea increases, the density of cones decreases, leaving only rods left
the retina is made up of millions of _________, each with a ______________ (2)
receptive fields
center and surround
the response to light exposure within a receptive field involves? (5)
- photoreceptors
- bipolar cells
- horizontal cells
- retina ganglion cells
- amacrine cells
the NT glutamate is released by photoreceptors when light is on/off ?
off
bipolar cells have one of 2 types of glutamate receptors, ionotropic or metabotropic. what’s the difference?
IONOTROPIC:
ion-gated fast ligand = fast depolarization
METABOTROPIC:
G protein = depends on a-subunit = hyperpolarizes
OFF bipolar cell = ___ glutamate
high
ON bipolar cell = ___ glutamate
low
what inhibits the amount of glutamate released from a photoreceptor?
action of horizontal cells
OFF bipolar cell = which type of glutamate receptor?
fast ligand gated Na+
OFF bipolar cell = which type of glutamate receptor?
fast ligand gated Na+
ON bipolar cell = which type of glutamate receptor?
G protein coupled, closes with glutamate
ON bipolar cell is maximally ______ by the ______ ________ when light is _______ the center receptive field and will release ______ onto the RGC
depolarized
center photoreceptor
striking
glutamate
OFF bipolar cell is maximally ______ by the ______ ________ when light is _______ the center receptive field and will release ______ onto the RGC
depolarized
the center photoreceptor
not striking
glutamate
OFF bipolar cell: how will the rate of glutamate released from the center cone change when light hits the surround receptive field?
ON bipolar cell: how will the rate of glutamate released from the center cone change when light hits the surround receptive field?
