Lecture 2 Flashcards
plastic (changeable) living organ that continuously changes in response to your ongoing experience
brain
single cell formed by the amalgamation of an ovum and a sperm
zygote
zygote divides to form ___ daughter cells
two
4 embryonic stem cells
- totipotent
- pluripotent
- multipotent
- unipotent
embryonic stem cell wherein the cell has the ability to develop into any class of cell in the body
totipotent
embryonic stem cell wherein developing cells have the abiilty to develop into many, but not all, classes of body cells
pluripotent
embryonic stem cell wherein new cells become more and more specialized and has the ability to develop into different cells of only one class
multipotent
embryonic stem cell wherein it can develop into only one type of cell
unipotent
5 phases of neural development
- induction of the neural plate
- neural proliferation
- migration and aggregation
- axon growth and synapse formation
- neuron death and synapse rearrangement
induction of neural plate happens ______
3 weeks after conception
small patch of ectodermal tissue on the dorsal surface of the developing embryo
neural plate
does not occur simultaneously or equally in all parts of the tube
neural proliferation
zone wherein most cell division in the neural tube occurs
ventricular zone & subventricular zone
two regions adjacent to the ventricle
- ventricular zone
- subventricular zone
runs along the midline of the ventral surface of the tube
floor plate
two organizer areas in the neural tube
- floor plate
- roof plate
runs along the midline of the dorsal surface of the tube
roof plate
play a key role in cell migration during development
radial glial cells
when do cells migrate to the appropriate target location?
once they have been created through cell division in the ventricular zone of the neural tube
two major factors governing migration
- time
- location
two kinds of cell migration
- radial migration
- tangential migration
proceeds from the ventricular zone in a straight line outward toward the outer wall of the tube
radial migration
occurs at a right angle to radial migration
tangential migration
two mechanisms of cell migration
- somal translocation
- radial-glia mediated migration
“the developing cell has a process that extends from its cell body that seems to explore the immediate environment”
somal translocation
somal translocation allows a cell to migrate in _____
either radial or tangential fashion
developing cell uses the long process that extends from each radial-glia cell as a sort of rope along which it pulls itself up and away from the ventricular zone
radial-glia-mediated migration
radial-glia-meditated migration allows a cell to migrate ______
only in a radial fashion
structure situated just dorsal to the neural tube; formed from cells that break off from the neural tube as it is being formed
neural crest
process in which the migrated neurons have aligned with other developing neurons
aggregation
3 non-exclusive mechanisms of aggregation
- cell-adhesion molecules (CAMs)
- gap junctions
- interactions between glial cells and neurons
located on the surfaces of neurons and other cells, have the ability to recognize molecules on other cells and adhere to them
cell-adhesion molecules
points of communication between adjacent cells; the gaps are bridged by narrow tubes
gap junctions
narrow tubes bridging the gaps
connexins
through this, the process of aggregation is achieved
interaction between glial cells and neurons
axon and dendrites grow after:
- neurons have migrated to their appropriate positions
- aggregated into neural structures
when is an appropriate pattern of synapses established?
once axons have reached their intended sites
formation of new synapses depends on the presence of glial cells
synaptogenesis
normal and important part of neurodevelopment
neuron death
passive cell death
necrosis
active cell death
apoptosis
2 neurotrophins
- nerve growth factor (NGF)
- brain-derived neurotrophic factor (BDNF)
tends to focus the output of each neuron on a smaller number of postsynaptic cells
synapse rearrangement
three major technical advances in studying the prenatal human neural tissue
- the development of three-dimensional brain organoids in culture
- ability to image the brains of prenatal humans
- characterization of cell-level transcriptomes
refers to the process of forming new synaptic connections between neurons
synaptogenesis
process of adding a productive myelin sheath to axons
myelination of axons
process of dendrites, the specialized extensions of neurons, developing additional branches or protrusions
increased branching of dendrites
displays the most prolonged period of development of any brain region
prefrontal cortex
cognitive functions associated with prefrontal cortex
- working memory
- planning and carrying out sequences and actions
- inhibiting responses that are inappropriate in the current context but not in others
- following rules for social behavior
tendency to continue making a formerly correct response when it is currently incorrect
perseveration
ability of nervous system to reorganize neuronal circuits and form new synapses even in adults
neural plasticity
proteins that control neural plasticity and reformation neural plasticity and regeneration in cns
neurotrophins
2 important principles of brain development
- the human brain starts to function in the womb and never stops working until one stands up to speak in public
- neurogenesis
complex neurodevelopmental disorder
autism spectrum disorder (ASD)
ASD is almost always apparent before the age of _____
3 yrs
two core symptoms of ASD
- reduced capacity for social interaction
- restricted and repetitive patterns of behavior, interests, or activities
ASD is a ______ disorder
heterogeneous
persons with general intellectual disabilities who nevertheless display amazing and specific cognitive or artistic abilities
savants
predictors of ASD
transcription related errors
neurodevelopmental disorder associated with intellectual disability and with a heterogenous pattern of abilities and disabilities
williams syndrome
difference between ASD and williams syndrome
individuals with WS are sociable, empathetic, and are talkative
cognitive deficits that comes with WS
- severe attentional problems
- bad spatial abilities
- non-existential ability to draw objects
- have negativity perceiving negative emotion in faces
