Chapter 2 Flashcards
Myelination occurs as a result of ______ communication between ______ and ______
- reciprocal
- neurons
- oligodendrocytes
Myelination occurs until at least age
28
Causes of changes of brain structure during childhood and adolescence
- changes in myelination and axonal quality
- changes in organization and density of synapses
Synaptogenesis in humans begins ______ and continues for ______
- the third trimester of fetal life
- a varying amount of time
Synaptogenesis in the auditory cortex peaks at _______
3 months
Synaptogenesis in the prefrontal cortex occurs until age
3.5, or longer
After synaptogenesis, ______ occurs
Synaptic pruning
A benefit of using MRI over other forms of imaging or post-mortem studies:
It allows you to study the same person over long periods of time
Brain volume _____ in the first year of life, increases by _____ in the second, and reaches ______ by age 6
- doubles
- 15%
- 95% of peak volume
White matter is composed of:
primarily myelinated axons
White matter development is _____ across the brain lobes
consistent
A key white matter structure is the ______
corpus callosum
What does the corpus callosum contain?
~200 million axons connecting the left and right hemispheres
What does diffusion tensor imaging do?
measures diffusion of water through different regions of the brain
What is fractional anisotropy?
A measure of the degree of nonramdomess of water diffusion
High anisotropy indicates ______, reuslting in ______
- bundled myelinated axons and axonal pruning
- more efficient neuronal signalling and improved cognitive performance
Grey matter _____ in childhood and _____ in adolescence
- increases
- decreases
Reductions in grey matter may reflect ______ and/or ______
- synaptic reorganization
- increases in white matter
Increases in grey matter start in ______ and lastly occur in ______
- primary sensorimotor areas
- higher-order association areas that integrate those primary functions
Grey matter volume is the product of _____ and _____
- cortical thickness
- surface area
Amygdala and hippocampus GM volumes increase during ages
1 month to 8 years
Basal ganglia GM volume ______ during adolescence, although data for the ______ is mixed
- decrease
- caudate
