Topic 1: Brain Development Flashcards
Development Stages of Brain (A, B, C,D, E, F)
Single cell -> Morula -> Blastula -> Cells develop on one wall of sphere -> formation of 2-layered embryonic disk -> gastrulation
Gastrulation
the process in which 3-layered embryonic disks develop
What does the primitive streak do?
establishes left to right and rostral-caudal symmetry
What are the three layers from superficial to deep in brain? And the tissues of each part?
ectoderm (nervous system and skin)
mesoderm(bone& muscles)
endoderm (viscera)
Morula? In what stage of tissue/ organ development?
the solid sphere of cells
the 2nd stage after fertilized eggs develop into a single cell
Blastula. What stage in tissue/ organ development?
the hollow sphere of cells
3rd stage after morula
Neuralation
the formation of neural tube
where does the formation of neural tube occur? from what?
in ectoderm
neural plate
what does notochord do?
signals the ectoderm to form the thick and flat neural plate
what does the neural tube do?
differentiate into spinal cord and brain, eventually forming CNS
What is the longitudinal development of neural tube?
its the development from rostral (head) end of neural tube to caudal end of neural tube into 3 primary brain vesicles
What are the 3 primary vesicles? What is the remaining of neural tube?
prosencephalon (forebrain)
mesencephalon (midbrain)
rhombencephalon (hindbrain)
spinal cord
Five secondary vesicles of prosencephalon
telencephalon
diencephalon
Cavities of telencephalon? of diencephalon?
lateral ventricles
third ventricles
Walls of lateral ventricles?
old factory bulb
hippocampus
cerebrum
what part of brain functions as smell?
old factory bulb of lateral ventricles
What part of brain does the memory storage?
hippocampus of lateral ventricles
What part of brain does the cognition, perception and voluntary activity?
cerebrum
Cavities of diencephalon
third ventricles
Wall of third ventricles
Retina
thalamus
hypothalamus
What part of brain does vision? (tell the origin for cavities, 5-vesicles brain)
retina of third ventricles (of diencephalon)
What part of brain does relay? (tell the origin for cavities, 5-vesicles brain)
thalamus
third ventricles of diencephalon
What part of brain does autonomic function? (tell the origin for cavities, 5-vesicles brain)
hypothalamus
third ventricles of diencephalon
Cavities of mesencephalon? Walls of mesencephalon?
cerebral aqueduct
midbrain
Fuction of midbrain?
head orienting movements
voluntary movements
neuromodulatory source
Five secondary vesicles of rhombencephalon
metencephalon
myelencephalon
Cavities of rhombencephalon
4th ventricle
Walls of Metencephalon
cerebellum
pon
Walls of myelencephalon?
medulla
Function of cerebellum?
coordination of movement
motor learning
Function of pon
Function of medulla
cerebrum > cerebellum
autonomic function, sensory nuclei, motor pathways
basal (floor) plate
alar (roof) plate
the ventral part of neural tube
the dorsal part of neutral tube
what epithelial layer that produces CSF?
ependyma
What is the mantle in neural tube?
the cell bodies of developing neurons
What is the marginal layer in neural tube?
the nerve fibers of developing neurons
Sulcus limitans
viscera
Stages in neural development (6 stages)
proliferation -> differentiation -> migration -> axon-path finding -> connection -> maturation
proliferation
How does cell proliferate?
the increase in number of progenitor (neural stem) cells
mitosis (symmetrical and asymmetrical divisions)
differentiation
undifferentiated cells (neuroblasts) become specialized neurons
migration
the cells travel horizontally & vertically
axon-path finding
growth cones
neuron grows to targets correctly
specialized growing tip of axon
connection in neural development
synpase and circuit formation
maturation
synapse elimination and cell death
neuroblast
undifferentiated neuron
symmetrical division
slow
generate two neural stem cells that can become either neuron or glia
asymmetrical divisions
fast but limited number of times cells divisions
generate a progenitor and a neuralblast
progenitor
neural stem cells
What does growth cones have? What are the guidance cues in axon path-finding?
the receptors for guidance cues which can attract or repel axons
fixed signals & diffusible signals
fixed signals (of axon path-fiding). Where you can find them?
the adhesive molecules
on cell surface or extracellular matrix
what are the matrix molecules?
laminin
fibronectin
Receptors for matrix molecules?
integrin
what are the adhesive molecules on the cell surface?
CAMs (cell adhesion molecules)
CADherin
What type of factors is diffusable signals? What does it do?
chemotropic factors
it attract or repel the growing axons
chemo-retracttant
chemo-repellant
growth cones move toward the source
growth cones move away from the source
netrin
where can you find it?
What does it do?
a chemotropic factor
in spinal cord
it attracts the dorsal horn neurons that across the midline to form the spinthalamic tract
robo
the receptor for slit
slit
the chemorepellant factor that cause the axons move away from the midline
Define the structures of color arrows of Picture A:
brown
dark blue
dark red
yellow
greenish blue
notochord
neural plate
primitive streak
ectoderm
mesoderm
Define the structures of color arrows of Picture B:
red
purple
pink
neural groove
neural crest
floor plate
Define the structures of color arrows of Picture C:
purple
green
pink
yellow
neural crest
somites
floor plate
neural tube
Define the structures of color arrows of Picture D:
green
brown
dark yellow
shit color
somites
sensory ganglia
neural tube
spinal color
What does neural crest contribute to the CNS development?
migrate and generate a progenitor number of differentated cell types
What does somites contribute to CNS development?
determine the migration pathways for neural crest cells and spinal nerve axons
what does thalamus do?
relay informations between sensory system and cerebral cortex
what does hypothalamus connect with? To do what? Arrow Color?
pituitary gland
to regulate the bodily functions
purple
Structure of midbrain
dorsal wall - tectum
ventral wall - tegmentum
cerebral aqueduct
What structure is #4? What part of brain is this?
tectum
dorsal walls of midbrain
Where is superior colliculus? Function?
Dorsal wall of midbrain (tectum)
movements initiated by visual input
Where is inferior colliculus? Function?
Dorsal wall of midbrain
movements initiated by auditory input
How does the development of forebrain occur (which sprout off first)?
telencephalon and optic vesicles sprout off first while diencephalon remains until later
what does optic vesicles develop into?
optic nerve and retina
What result in the formation of cerebral hemispheres?
telencephalic vesicles
What structure grow to cover the diencephalon?
cerebral hemispheres
Tell the structures of the image from #1-4
1- diencephalon
2- telencephalon
3- optical vesicles
4- Midbrain
Tell the structures of the image from #5-8
5-Hindbrain
6- Myelencephalon
7- Metencephalon
8- Spinal cord
Tell the structure of picture C according to color arrows:
Blue
yellow
red
purple
brown
green
cerebral cortex
lateral ventricles
thalamus
hypothalamus
basal encephalon
third ventricles
Tell the structure of picture D according to color arrows:
orange
light orange
light green
corpus callosum
cortical white matter
internal capsule
What are two types of gray matter in telencephalon? Where do you find them?
cerebral cortex
basal encephalon
walls of encephalon
what are three major white matter systems develop?
cortical white matter
corpus callosum
internal capsule
association pathways
What structure does it involve in? Arrow color?
the interconnection pathway within a cerebral hemisphere
cortical white matter
light orange arrow
What structure and pathways does the forebrain interconnect with other hemisphere? Arrow color?
via corpus callosum and commissural pathways
orange arrows
What structure and pathways does the forebrain interconnect with spinal cord and brain stem? Arrow Color?
internal capsule
projections pathways
light green (picture D)
Through what white matter systems does the relay information btw sensory system and cerebral cortex occur? What structure of diencephalon do this job? Arrows Color for each?
internal capsule (light green)
thalamus (red)
What is the only part of brain doesn’t subdivide?
midbrain
What structures tegmentum develop into? Number of this picture? What is it function?
substantia nigra & red nucleus
voluntary movement
What does tectum subdivide into?
superior and inferior colliculus
Explain the neuromodulatory source of tegmentum? Why is it signifcant?
tegmentum contains widespread projections of axons throughout CNS
regulate mood, consciousness, pleasure and pain
What part of the brain is this? What is structure of #5?
midbrain
cerebral aqueduct
What part of the brain is this lower picture?
hindbrain
What structure is #1? What part of 5 secondary vesicles is #1 in? What does it do?
cerebellum
dorsal wall of metencephalon
motor learning and motor coordination
What structure is #2? What structures does it have above and bellow (in relation among cerebellum, pons and modulla) ?
4th ventricle
cerebellum above
pons and medulla below
What structure is #3? What part of 5 secondary vesicles is #3 in? What does it do?
Pons
Ventral wall of metencephalon
relay information from cortex to cerebellum
What part of the 5 secondary vesicles of brain is the lower picture?
myelencephalon
vWhat structure is #1?
4th ventricle
What structure is #2? What part of 5 secondary vesicles is #2 in?
medulla
ventral and lateral wall
What structure is #3? What part of 5 secondary vesicles is #3 in? What does it do?
medulla pyramids
myelencephalon
What type of matter (white/ gray) is medulla pyramids? What does it do?
white matter
relay motor information from cortex to spinal cord
What does the nuclei of medulla do?
What does the circuitry of medulla do?
Sensory system of touch, hearing and taste
autonomic system functions (respiration, cardiovascular control)
What structure contains cranial nerve nuclei 3-12? Structure #?
the floor of tegmentum
6
What structures does gray matter of spinal cord develop into?
dorsal horn
ventral horn
intermediate zone
What structure is #2? What does it do?
dorsal horn
receive sensory inputs
What structure is #3? What does it have?
intermediate zone
interneurons
What structure is #4? What does it do?
ventral horn
project motor axons to innervate muscles
What structure is #1? What structures does it develop into?
white matter
dorsal columns
ventral columns,
lateral columns
white matter is_______, gray matter is ______ (in spinal cord?
peripheral
centrally
dorsal column (of white matter)
lateral columns
ventral columns
carry somatosensory information toward brain
carry descending motor axons
carry descending motor axons and ascending pain
What kind of divisions will most likely predominant in the early neural development? Why?
symmetrical divisions
Asymmetrical divisions happens with limited # of times to generate cells -> Not preferable
Which layer of cortex is the 1st “born”?
VI
growth cones
what does it have?
the specialized growing tip of axon
the receptors for guidance cues which can attract or repel axons
fixed signals
the guidance cues that are adhesive molecules which can attract or repel axons
diffusible signals
chemotropic factors that can pull axons toward or away from the sources
apoptosis
necrosis
the programmed cell death
the cell death in response to injury
trophic factors
What does it do with apoptosis and neurons?
the life-sustaining factors with limited availability in target cells
It save neurons by switching off the apoptosis
What will happen if there are too many neurotrophin?
What will happen if there are no neurotrophin?
neurons will be surplus in high levels
apoptosis (neuron death)
Hebb’s rule
neurons that fire together, wire together; neurons that fire out of sync, lose their link
critical periods
the specific times during the development is under influence of environment the most.
What will happen if a normal child is deprived of hearing spoken language during critical period?
they will never acquire normal language
Where do we find neurexin?
pre-synapstic membrane
Where do we find neurolignin?
post-synapstic membrane
postsynapstic density
what does it do? Why?
a specialized intercellular junction
localizes the neurotransmitter receptors, channels and signaling molecules
to facilitate the postsynapstic response to neurotransmitter
