Neuroplasticity 1-3 Flashcards
at birth - neural circuits
Rough draft of neural circuits - genetically determined
after birth - neural circuits
neural circuitry is refined by experience - experience dependent reorganzation
Experience dependent reorganization
Based on the experience that the brain gets
when does plasticity occur in response to experience
continues throughout life
particularly heightened during critical periods
Orphan study
Neurocognitive dysfunction is evident in children under social deprivation in orphanages
Longer they stay in orphanage, the higher the incidence of cog impairment
Orphan study - what part of the brain was it noticeable in
Uncinate fasciculus - not as developed in the socially deprived child
visual cortex receives information from
both eyes
Ocular dominance columns
certain areas only receive either left or right eye input
First step of visual perception - crucial that they are separated in this layer and then become integrated in another layer (because of experience)
Ocular dominance - when are the columns developed by
6 weeks
Merzenich - monkeys with sutured fingers together
inputs of 2 fingers always coming into the cortex together - abolishes the sharp zones of the map
Syndactyly
congenital fusion of the fingers - cortical map of the hand is reduced overall - representation of the fingers is not organized somatotopically
Phantom limb sensation -
scar of nervous tissue in strump caused the pain - reorganization of cortical circuits
Remapping occurs - face
Musicians and age started
The earlier they started to play, the more cortical response you see
Does the type of experience or activity determine the type of plasticity
YES
Complex environment paradigm - Rat study
EC rats superior performance in running mazes - also they had heavier and thicker cerebral cortices - more synapses - more dendrites
Complex environment paradigm - Rat study - EC rats synaptogenesis compared to IC and SC rats
More dendrites, more synapses per neuron in a number of brain areas
New syanpses persisted beyond exposure to EC
Saw synaptogenesis in older rats
Moved EC to IC and still saw new synapses
EC rats - was synaptogenesis due to learning or just more general activity - study that answered this question
Acrobatic rats/motor learning vs. Free exercises (treadmill)
ML rats - more synapses
FE rats - more angiogenesis
Glial changes with motor learning rats and free exercise rats
EC had greater number and size of glia, enhanced synaptic function (reuptake NT, cleaning up debris)
Take away from motor learning rats vs. free exercise rats
Task specificity
We want to do both inc synapses but angiogenesis is good too because it produces a better environment for the neuron
Both important - but just know why it is important to do what you are doing - know your goal
Concept of LTP and LTD
Synapses that fire together, stay together
LTP occurs in synapses that
are already active AND in silent synapses
NMDA and AMPA are what type of receptors
glutamate
NMDA or AMPA - which is normally activated
AMPA - leads glutamate to come in and it may or may not bring to threshold
NMDA or AMPA - which is not normally activated
NMDA - activated with high frequency - presynaptic cell is discharging a lot of glutamate
