brain development Flashcards
3 approaches to studying the brain
1) Correlate nervous system development with the development of specific behaviors
2) Look at behavior and make inferences about brain development
3) Examine factors that influence both brain development and behavioral development
the development of parietal lobe areas and grasping is an example of what approach to studying the brain
Correlate nervous system development with the development of specific behaviors
at birth children do not speak, so the neural structures underlying speech production are not yet developed (we assume the structures are under development. an example of what approach to brain development ?
Look at behavior and make inferences about brain development
if some toxin affects language development, we assume it also affects brain development. an example of what approach to brain development,
Examine factors that influence both brain development and behavioral development
the brain looks human after how many days?
100
when does the brain gyri and sulci develop
7 months
what is a neural tube and when does it develop?
rolled up sheets of cells that will form the brain and spinal cord
- begins to develop at weeks after conception
7 stages of brain development
1) cell birth (gliogenisis, neurogenisis)
2) cell migration
3) cell differentiation
4) cell maturation (dendrite and axon growth)
5) synaptogenesis (formation of synapses)
6) cell death and synaptic pruning
7) mylogenisis (formation of myelin)
Grow out of the neural tube and Have capacity for self-renewal. what is this?
neural stem cells
progenitor cells are produced by? and produce?
neural stem cells, neuroblasts and glioblasts
what is lined with neural stem cells
sub- ventricular zone in adults
what goes through neurogenesis in adults
sub ventricular zone in adults
Primitive” map in subventricular area guides cells to predisposed cortical location
cell migration
cell migration builds from ?
inside to outside
cell migration continues for how long?
until about 8 months after birth
radial glial cells extend form where to where?
sub ventricular zone to cortical areas
Neurons migrate out by traveling along “roads” of these cells
radial glial cells
the brain is more sensitive to trauma during?
migration as opposed to generation
why is the brain more sensitive to trauma during migration?
if cells get put in the wrong place due to trauma, they will always stay there and interfere
neuroblasts become specific types of neurons during?
cell differentiation
cell differentiation is essentially complete when?
at birth
neuron maturation (synaptic and dendritic growth) continues into?
adulthood (get actual connections)
neuroblasts cells produce
projecting neurons and interneurons
glioblasts produce
oliogodendroglia and astrocytes
development of the dendrites happens when
neural maturation
Dendritic arborization is what? and is part of what stage?
branching, neural maturation
growth of dendritic spines happens in what stage
dendritic maturation
is development of dendrites is a ? process
slow (continues long after birth) (micrometers a day)
Have specific targets to reach and A slightly faster process (millimeter/day). development of what?
axons
the development of axons is part of what process
neural maturation
what can travel great distances?
axons
5 phases of synaptic pruning and formation
1 and 2: Take place in embryonic life and generated independently of experience
3: Rapid growth – both pre and postnatal – 4: Plateau and rapid elimination through puberty (pruning)
5: Plateau in middle age, then steady decline with age
synaptic pruning differs depending on what?
cortical region
striate pruning occurs prior to?
prefrontal pruning
experience expectant and experience dependent are part of what process
synaptic growth and formation
Development depends on the presence of sensory experiences
experience expectant
experience expectant is part of what phases of synaptic pruning
phases 3 and 4 (early in life)
Generation of synapses that are unique to the individual
experience dependent
experience dependent is part of what phase of synaptic pruning
3 4 and 5 (throughout life)
glial development begins after what ?
neuronal birth and continues through life
Allows for normal adult function (quick and efficient communication
myelination
myelination is part of what developmental process
glial development
myelination begins when and ends when?
begins at birth and goes until 18 years of life
different areas of the cortex are myelinated at?
different times
the areas of the brain myelinated last are usually for?
more complex processes (executive function )
Piaget: Stages of Cognitive Development
and timing
Sensorimotor (Birth to ~1.5-2 years)
Preoperational (~2-6 years)
Concrete operations (~7-11 years)
Formal operations ( 12+ years)
Object permanence (what stage of cognitive development)
sensorimotor
Can understand Conservation (take things literally) (what stage of cognitive development)
concrete operations
abstract reasoning (what stage of cognitive development)
formal operation
Can represent things with words and drawings (e.g., language development) (what stage of cognitive development)
preoperational
the piagetian stages of development correspond too?
growth spurts in brain to body ratio
Deprived environments and traumatic experiences can adversely impact physical health, mental health, and cognitio
aversive environments
has shown long-term affects on neurological function and increased risk for addiction, suicidality, and mental health disorders
adverse childhood experiences (ACE)
Benefits of environmental complexity • Adverse effects of prenatal drug exposure • Gene expression is impacted by maternal diet during prenatal development • If rats are in a more stimulating environment they will get more spine density and dendritic length (nutrients the fetus gets also influences this)
environmental effects
Inattention (more girls) – Hyperactivity/Impulsivity (Most common disturbance)
-exemplifies what?
ADHD
what % of children in the US diagnosed with ADHD
5%
ADHD is associated with what brain regions
ventral/inferior areas of the frontal lobe (impaired self regulation)
Children display impaired social interaction, narrow range of interests, language and communication abnormalities – May have preserved intellect
- exemplifies what?
autism
genetic influences of autism?
DUF 1220 increased repeats leads to more brain cells (# of repeats correlates with the size of head
2 brain abnormalities associated with autism
1) larger head and brain size then normal (pruning? brain cell division?)
2) Failure of the von Economo neurons in frontal cortex to develop normally(associated with theory of mind defiecits)
Physical Malformation and Intellectural Impairments (exemplifies what?
FASD
brain abnormalities of children with FASD
1) Smaller brains
2) Abnormal gyri (folds don’t develop as well) “flat brain”
3) Abnormal clusters of cells & misaligned cells in cortex
Learning disabilities, low IQ, hyperactivity, and social problems
- exemplifies what?
FASD
dementia occurs in % over 65 and % over 80?
5-7%, 50%
DSM-5 diagnosis categories – Major/Mild neurodegenerative disorder (NCD)
- exemplifies what?
dementia
the most prevalent dementia
Alzheimer’s
dementia accounts for % of people with dementia over age 65
65%
Neuritic (Amyloid) Plaques are found in what? and are positively correlated with?
cerebral cortex. cognitive decline
Paired Helical Filaments are known as? and found where?
neurofibrillary tangles, cortex and hippocampus
neuritic plaques and paired helical filaments are associated with?
alzheimers
neocortical changes of alzheimers?
shrinkage of the cortex (degeneration of the limbic system and entorhinal cortex)
cell changes of alzheimers
cell shrinkage
loss of dendritic arborizations
Gradual progression of loss: – Recent memory – Remote memory – Ability to recognize family members
alzheimers
