NS_Embryo Flashcards
What are the Primary Cerebral Vesicles?
Prosencephalon (Forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
The Primary Cerebral Vesicles are hollow neural tubes along the ____?___ axis?
rostrocaudal
What are the secondary brain vesicles?
Telencephalon Diencephalon Mesencephalon Metencephalon (cranial) Myelencephalon (caudal
Mesencephalon → ?
Mesencephalon & Aqueduct of Sylvius
Prosencephalon (forebrain) →
Telencephalon & Diencephalon
Paired Telencephalon → ?
cerebral hemisphere; each w/ lateral ventricles
Diencephalon → ? (5)
thalamus hypothalamus subthalamus epithalamus third ventricle
Rhombencephalon →
Metencephalon (cranial)
myelencephalon (caudal)
fourth ventricle.
Metencephalon → ?
pons, cerebellum
Myelencephalon → ?
medulla
pons, cerebellum, and medulla all come from what secondary cerebral vesicle?
Rhombencephalon
Neural Tube → ?
Spinal cord and Central Canal
what are Rhombomeres?
8 morphologically distinct elements of rhombencephalon.
Cells in each rhombomere differ in morphology, axonal trajectory, NT synthesis, NT selectivity, firing properties, and synapse specificity
What are Morphogens?
secreted by anterior and posterior structures, establishing a concentration gradient along AP axis
Basal plate = ____1____
alar plate = ____2_____
sulcus limitans = _____3_____
Basal plate = ventral
alar plate = dorsal
sulcus limitans = separating the two
Neural progenitors in cord develop into distinct populations based on position along ____?____ axis
dorsal-ventral (DV)
Ventral aspect of neural tube → ?
motor neurons
Dorsal aspect of neural tube → ?
neurons receiving sensory input from cells of dorsal root ganglion carrying sensory information
Morphogens are secreted by __________ and __________ structures, establishing a concentration gradient along __-axis
anterior and posterior
AP axis
What are the morphogens secreted from the Primitive Node?
Wnts, FGFs, Retinoic Acid → Caudal structure development
What are the morphogens secreted from the Anterior Visceral Endoderm (underlying prechordal plate)?
Cerebrus, dickkopf → Forebrain development
Failed regression of the neurenteric canal results in ____________ and _____.
neurenteric fistulas and cysts.
Treatment for schizophrenia = block ____ and ____ receptors
D2 and 5HT receptors
Functions of dopamine include initation of voluntary movement, reward-related behavior, and control of attention.
NE regulates arousal, attention, vigilance, sleep-wake cycle, fear response/anxiety, and mood.
Epinephrine plays a role in regulating blood pressure.
While functions of these neurotransmitters can overlap, the best answer here is voluntary movement as dopamine definitely plays a role in that (while the others do not play a significant role in that type of regulation). Note that DA in the periphery causes vasodilation and hypotension via D1 receptors on vessels.
Functions of dopamine include initation of voluntary movement, reward-related behavior, and control of attention.
NE regulates arousal, attention, vigilance, sleep-wake cycle, fear response/anxiety, and mood.
Epinephrine plays a role in regulating blood pressure.
While functions of these neurotransmitters can overlap, the best answer here is voluntary movement as dopamine definitely plays a role in that (while the others do not play a significant role in that type of regulation). Note that DA in the periphery causes vasodilation and hypotension via D1 receptors on vessels.
Voltage-gated K+ channels ___1___ up repolarization, ___2___ the duration of the action potential
- Speeds
2. shortens
Walls of neural tube initially are pseudostratified ectoderm called the _____________.
neuroepithelial layer
Walls of neural tube initially are _________ ectoderm called neuroepithelial layer
pseudostratified
Walls of neural tube initially are pseudostratified _______ called neuroepithelial layer
ectoderm
Radial migration: ?
Radial Migration: migration away from inner multiplication zone to outer edges of growing wall of neural tube.
(this is happening in the neuroepithelial layer)
Radial Migration: migration away from the ____________ zone to outer edges of growing wall of neural tube.
inner multiplication zone
Neuroepithelial cell layer will form all cellular elements of CNS, except what?
Neuroepithelial cell layer will form all cellular elements of CNS (except microglia)
Period of rapid cell replication of daughter cells in this layer anteriorly → cell migration
The telencephalon develops in an ____1____ manner when Cells follow ___2___ glial guides → important preceding cells “get off” the ladder before others can follow.
- “inside-out”
2. radial
Cells “decide” to exit cell cycle in M phase after their _______ - thought that nuclear migration contributes to exit from cell cycle
birthdate
________ cleavage to ventricular surface → both daughter cells remain attached to ventricular surface and continue dividing in cell cycle
Perpendicular
________ cleavage to ventricular surface → only one daughter cell still attached to ventricular surface → exit cell cycle and begin differentiation.
Parallel
Parallel cleavage to ventricular surface → ___________ division
ASYMMETRIC DIVISION
After a cell’s “birthdate” it divides and exits the cell cycle from M phase
Cell then begins _______?
neuronal differentiation
Neurons that are born at the ____ time tend to end up together in the same layer, and follow similar programs of differentiation
same
When Myelination Occurs:
- Begins during embryonic stages in periphery
- CNS myelination first observed in spinal cord near end of first trimester, by third trimester, myelination present in brain
- Myelination of cortical tracts involved in higher functions occurs after birth
- Corticospinal tract begins to be myelinated prior to birth, but only extends past medulla after birth
Myelination of cortical tracts involved in higher functions occurs before or after birth?
after birth
Corticospinal tract begins to be myelinated ___1___to birth, but only extends past ___2___ after birth
- prior to birth
2. medulla
Brain Regions of Secondary Neurogenesis: regions of brain that are what?
Brain Regions of Secondary Neurogenesis: regions of brain that are hotspots for postnatal neurogenesis
Brain Regions of Secondary Neurogenesis: regions of brain that are hotspots for postnatal neurogenesis.
- External Granule layer –>
- Subventricular zone –>
- Dentate Gyrus –>
- Cerebellum (neurogenesis until age 2)
- Olfactory neurons
- Hippocampal cells
All 3 cell types of secondary zones of neurogenesis share 3 characteristics:
All 3 cell types of secondary zones of neurogenesis share 3 characteristics:
1) Arise in ventricular zone
2) migrate before exiting mitotic cycle to a new non-ventricular location
3) Proliferate postnatally in non-ventricular zone locations
Granule layer initially located near rim of ___ ventricle, but cells migrate very high on top (near pia) before they are postmitotic to form a new neurogenic “secondary” region = External Granule Layer
4th ventricle
External granule cell progenitors proliferate and once they exit the cell cycle, migrate to ________ (further down toward ventricle)
cerebellum
Subventricular Zone - Olfactory Neurons:
Cells initially located in ventricular zone of ______ ventricles → migrate very small distance before exiting mitotic cycle to subventricular zone.
lateral ventricle
Cells in subventricular zone give rise to olfactory bulb neurons.
Cells exit cell cycle and migrate ______ to location of olfactory bulb
rostrally
Neurogenesis: the process of generating neural cells. When does it begin?
Neurogenesis begins after the neuroectoderm rounds up and forms the neural tube.
During Neurogenesis , Proliferating cells are located in ________ (layer nearest to neural tube lumen/ventricle or central canal)
ventricular zones
Proliferating cells are located in ventricular zones, where is the ventricular zones located.
VZ: layer nearest to neural tube lumen/ventricle or central canal
Developmental regulation of GABA receptors:
In adult: equilibrium potential (ECl) near or negative to resting membrane potential → GABA is ____1_____
During development: intracellular levels of chloride are elevated, ECl more +
GABA → _____2______
- inhibitory.
2. depolarization and excitation (excitatory)
Down Syndrome:
First postnatal years - dendritic spines are abnormally thin and short
May be due to abnormal pruning and/or synapse maturation processes that require neuronal interactions
