Von Bartheld Plasticity Flashcards
Explain plasticity?
you have a bunch of synapses and end up with much fewer
A mature muscle fiber receives innervation from how many neurons?
one
Synapses require a certain minimal level of (blank) support to persist
trophic
Where do synapses that want to persist get their nutrition?
from factors secreted by postsynaptic (target) cells in response to synaptic activation
Synapses can only utilize trophic support when what two things coincide?
their activity and the activiy of the target cell coincide :)
How do nerve fibers get to their desired target and their targets trophic factors?
they compete for them, may the best synapse win!
What regulates the competing synapses?
the patterning of the pre- and postynaptic activation
What did hubel and wiesel discover about lack of experiences during early postnatal life?
showed that the brain translates the effects of early experience (neural activity) into permanantly altered wiring!!!!
where do the afferent fibers of the lateral geniculate nucleus terminate?
in the primary visual cortex
The afferent terminals from the lateral geniculate of the eye form an alternating series of eye-specific domains in the cortical layer IV called the (blank)
ocular dominance columns
Ocular dominance columns were important in early studies of cortical plasticity, as it was found that monocular deprivation causes the columns in the deprived eye to (blank), with the non-deprived eye assuming control of more of the cortical cells and thus growing. (i.e good eye takes over)
degrade
(blank) are stripes of neurons in the visual cortex of certain mammals (including humans) that respond preferentially to input from one eye or the other
Ocular dominance columns
The input to from LGN to layer IV is (blank) but cells at the border of the layer IV and above and below layer IV integrate inputs from (Blank) responding to bioncular visual stimuli.
segregated
both eyes
If you deprive one eye of vision what will happen to your peripheral visual pathways?
nothing, they will remain normal BUT the synapses will not be connected thus you will not be connected to the visual cortex and will be functionally blind in that eye (i.e eye itself fine but the synapses are messed up)
When you get deprivation in one eye during the critical postnatal period, is your cortical blindness (amblyopia) permanent?
yes
What happens if an adult gets their eye shut?
nothing, they will not become blind and there neurons will remain synapses the way they were previously
Correlated activities between pre and post synaptic terminals equals (blank) bonds
stronger bonds
What happens when you have strabismus to your ocular dominance columns and your and binocular neurons in the cortex?
ocular dominance columns sharpen
loss of binocular neurons
Cortical neurons in animals with strabismus are driven by (one eye/both eyes)
right or left, but not both
Since we know that strabismus can cause loss of binocular neuons and thus binocular vision, what should we do with children who have strabismus?
correct there eyes with surgery ASAP before their synaptic connections are made and they lose binocular vision
What is another name for cortical blindness? How can you attempt to fix amblyopia?
amblyopia
forcing patient to use weak eye during critical period (i.e alternating eye patches)
What do presynpatic nerve fibers compete for?
neurotrophins, trophic factors, NO, NMDA receptors and Ca are involved
What besides ocular dominance occurs during the critical period in cute fluffy animal?
imprinting
Imprinting is characterized by a critical period and the relative (blank) of the behavior
stability
T/F
social and emotional behaviors require a particular sort of experience during a limited window in early life
T
What is super sad about abnormal experiences occuring during the critical period?
may induce abnormal patterns of brain circuitry that cannot be rectified later in life :(
Early deprivation of normal experience could lead to (blank).
mental disorders (such as neuroses)
A (blank) is an opacity of the lens that prevents normal vision.
cataract