6. Normal Development of the Central Visual System Flashcards
What happens during E68
right and left eye synapses are intermixed
What happens during E77
the inputs from the 2 eyes start to separate into clusters
What happens during E91
the LGN has found its position sitting to the side and beneath the thalamus, where there are distinct dark and light clusters
What do the dark areas of the LGN correspond to?
input from the contralateral eye
What do the light areas of the LGN correspond to
input from the ipsilateral eye
What happens during E130
speckles start to move to form layers
At what time does enucleation of one eye lead to clusters of empty space where input from the enucleated eye should be
Enucleatinon at E91
during gestation, what is the source of synchronous firing?
waves of calcium moving through the retina
-more intense the calcium=greater the number of action potentials coming from that specific area in the retina
synchronous firing of ganglion cells helps organize precise retinotopic projections to the LGN that separate into what?
what does the cortex separate into?
LGN=layers
cortex=ocular dominance columns
what is the basis for the formation of layers in the LGN and coarse VF layout?
synchronous firing in response to calcium in the retina
where do inhibitory interneurons originate from? how do they travel? via what?
originate in the striatum and travel horizontally through the cortex via amoeboid actions
-form connections between cortical columns rather than w/in them
what are the 3 types of neurons in the infant rat hippocampus?
place cells: fire when rat is in specific place w/in their environment
direction cells: fire when rat is facing a specific direction
grid cells: fire at the vertices of a regular repeating grid that covers the environment, environment expands the grid will expand and become less precise
which cells in the hippocampus of a rat take the longest to develop?
grid cells take about 2 days
place and direction take seconds
what cells beocme finely tuned into columns in the auditory cortex?
pitch and location cells
what develop in wenicke’s area
phoneme detectors for specific sounds develop
