Primary visual cortex Flashcards
Nissi technique
stains the rough endoplasmic reticulum, visualizes cell bodies
golgi technique
fills almost entire cell, visualizes structure of isolated cells
weigert technique
stains myelin, visualizes axonal processes
Cytochrome oxiddase (CO) technique
CO is a mitochondrial enzyme involved in ATP production, active cells express more of this enzyme, visualizes cell bodies, cells that have higher metabolism stain more darkly
pyramidal neurons (E)
pyramid-shaped cell body, long apical dendrite that extends through several layers of cortex collects and integrates information from many layers
granular neurons (B)
round cell body, much smaller than pyramidal, short, locally extending dendrites, performs local integration and dissemination of informatioin
number of layers throughout the cortex
6
brodmann’s area 17
primary visual cortex
highest density layer of the primary visual cortex
Layer 4C
which staining of layer 4C is dense
Nissi
which staining demonstrates a functional columnar organization?
CO
V1 layer 1
intracortical interactions
V1 layer 2/3
processing and output (k input)
V1 layer 4
input from P and M LGN
V1 layer 5
processing and output
V1 layer 6
processing and feedback
Sub-layer 4C-alpha connections
input from M cells of LGN and projects to 4B
Sub-layer 4C-beta connections
input from P cells of LGN and projects to layers 4A, 2, 3, 5
Sub-layer 4B composition
large pyramidal cells
Sub-layer 4B connections
input from 4C-alpha and projects to MT and V2
Sub-layers 4A composition
small granular neurons
Sub-layer 4A connections
input from 4C-beta and projects to layers 2 and 3
layer 1
Intracortical interactions: few neurons, dense network of synapses
layer 2/3
Processing and output; primary input from the Konio and Parvo sublayers of the LGN; contains “blob” and “interblob” areas; projects to “higher” visual cortex
layer 5
Processing and output; receives input from nearly all other layers; provides output to superior colliculus
layer 6
Processing and feedback; receives parvocellular input from LGN; forms a neural loop with the LGN (reciprocal connections)
center-surround receptive field
exclusively found in layer 4C, center=feed-forward, middle=horizontal connections, outer=feedback
simple receptive field
orientation selective, may be monocular or binocular, seperate on and off subregions
complex receptive field
orientation selective, binocular, no seperation between on or off subregion
end-limited receptive field
sensitive to width, orientation, length
double color opponent receptive field
red/green or blue/yellow, similar to on/off stimulus
disparity sensitive receptive field
involved in depth perception for near objects
critical period
appropriate visual input during critical period is necessary for developing proper connections - demonstrates visual cortex is not hard wired
amblyopia
reduces acuity due to problem in eye or visual pathway that hinders normal development - causes changes in the numbers, types, and connections of neurons throughout the visual pathway beyond the retina
inter-stripes
form information
positive disparity
object farter away, high rates of activity
negative disparity
objects closer, low rates of activity
