Unit 2 Flashcards
Afferent nerves
Sensory nerves
Efferent nerves
Motor nerves
The Somatic Nervous System
Affects the skeletal muscles; conscious movement
The Autonomic Nervous System
Affects the internal organs; unconscious movement
uses norepinephrine
the sympathetic system; part of the autonomic PNS
uses acetylcholine
the parasympathetic system; part of the autonomic PNS
responsible for fight or flight
the sympathetic nervous system
responsible for rest and digest
the parasympathetic nervous system
FGF in the midbrain/hindbrain
high concentration in posterior, low concentration in anterior
FGF in the forebrain
hign concentration in anterior, determines somatosensory cortex location
Adrenergic receptors
in the sympathetic system; responds to adrenaline
Cholinergic receptors
in the parasympathetic system; responds to acetylcholine
Three characteristics of stem cells
unspecialized, capable of self renewal, capable of differentiation
Where do neural crest cells move from?
The boundary between the neural tube cells and the epidermis
Spinal cord segments in order
Cervical, Thoracic, Lumbar, Saccal, Coccyx
Houses the sensory nerves
Dorsal root ganglion
pyramidal neurons
cortex neurons that can send processes over long distances
stellate neurons
cortex neurons that are mostly interneurons
glutamatergic cortical neurons
pyramidal neurons; use glutamate
GABAnergic cortical neurons
stellate neurons; use GABA
Which molecule plays a role in contact inhibition of NCCs
epherin
If cholinergic neural cells from the head are grafted to the trunk, they become
adrenergic neurons
If adrenergic neural cells from the trunk are grafted to the head, they become
cholinergic neurons
Extrinsic developmental influence means
final cell destination determines cell fate
Intrinsic developmental influence means
cell type and initial location determine cell fate
What is a mitogen?
a molecule that induces/stimulates mitosis; aka growth factor
What is the order of neural development?
Big neurons, small neurons, then glia
Radial glia are ___ and ___
neural progenitors and guide neurons
quit fraction
% of cells that exit the cell cycle
Neural Crest Cells can become
melanocytes, sensory neurons, and autonomic neurons
Shh gradient in neural tube
high concentration in ventral, low concentration in dorsal; from the notochord
caudal
tail/posterior
rostral
head/anterior
Where is the basal part of the neural tube
toward the external (pial) surface
where is the apical part of the neural tube
toward the ventricle
Retrovirus Lineage Tracing
A retrovirus infects a cell with a fluorescence gene; currently dividing cells will incorporate the fluorescence gene into their DNA so growing cells will fluoresce. All daughter cells will contain the fluorescence gene so the cell’s lineage can be traced.
Clonal analysis
only a few cells are infected retrovirally
Birthdating with BrdU/EdU
Tagged thymidine is incorporated into dividing cells’ DNA
Pulse-chase experiment
Pulse cells to label w=them with a compound; follow the cells for a long period of time. If the cells contain the label, the neurons were born at the time of the pulse, some color: born shortly after the pulse; no color, born well after the pulse.
Cortical layers are determined ___
temporally
Spinal cord layers are determined ___
spatially
High concentrations of p27 causes
a higher Q fraction; less mitotic cells; thinner cortex
Low concentration of p27 causes
a lower Q fraction; more mitotic cells; thicker cortex
How do neurons end up using different neurotransmitters?
They arise from different regions then migrate
The Par Complex
determines the half of the stem cell offspring that will retain “stemness” after asymmetric cell division
Numb proteins
determine the half of the stem cell offspring that will be more differentiated after asymmetric cell division
How does manipulating Shh gradient impact dorsal-ventral gradient?
D-V patterning is affected through TFs which change cadherin expression which leads to different cell adhesion of neural cells
Where do oligodendrocytes arise from?
From the same place as motor neurons, ventral spinal cord;
What cells do radial glial cells give rise to?
ALL cell types of the CORTEX
Cajal-Retzus cells are an exception to
the inside-out development of the cortex; generated first and form the outermost layer of the cortex.
Four developing cortical zones
Marginal zone (Cajal-Retzus cells), Cortical plate (layers 6-1), Intermediate zone, Ventricular zone (stem cell niche)
How do stellate neurons reach their destination?
They migrate tangentially from the MGE (Medial ganglionic eminence) to the cortex
Order of cortical cell layer development
Preplate > divides into Cajal-Retzus Cells and Subplate, Layer 6 > 5 > 4 > 3 > 2 > 1 develop between the CR cells and the subplate; inside-out development
Proneural TFs
Neurotrophins, FGF
Pro-astrocytic TFs
Notch, EGF, BMP, CNTFs
Purkinje cells produce ___
Sonic Hedgehog (Shh)
Granule cell progenitors have receptors for ___ that is produced by ___
Shh that is produced by Purkinje cells;
High Shh encourages granule cell progenitors to
make more granule cells;
The function of Reelin in the cerebral cortex
Ensures inside-out development of cortical layers
Reelin is produced by
Caja-Retzus cell in the preplate cortical layer; migrating neural cells have reelin receptors in order to direct their migration
Dentate gyrus
region in the hippocampus that has adult neurogenesis (as seen in environmentally stimulated mice)
The two most active regions of adult neurogenesis are
the hippocampus and the subventricular surface responsible for olfactory nerves
How do neural crest cells know where to migrate?
Contact inhibition with other neural cells and differential ephrin concentrations
Temporal order of cortical cell development
neurons, glia, astrocytes
Four types of cells in the cerebellar cortex
Purkinje cells, granule progenitor cells/granule cells, stellate cells, golgi epithelial cells aka Bergmann glia
How are aortic adrenergic PNS neurons determined
Sensory neurons generated in the neural tube migrate ventrally, if they come in contact with the aorta they become sympathetic
Which factors are present in the epidermis
BMP/Wnt
Which factor is present in the notochord
Shh
If a neural crest progenitor cell migrates dorsolaterally, it becomes
a pigment cell, melanocyte (early wnt signal from epidermis)
If a neural crest progenitor cell migrates ventrolaterally, it becomes
a sensory neuron (late Wnt signal from the muscles)
If If a neural crest progenitor cell migrates ventrolaterally and then medially, it becomes
an adrenergic autonomic neuron aka sympathetic neuron (BMP signal from dorsal region of aorta)
Schwann cells myelinate
one neuron
Oligodendrocytes myelinate
multiple neurons at once
Low concentrations of NRG lead to
neuron formation; as the cells migrate, they are in less contact with one another
NRG receptors are located on
migrating neural crest cells
High concentrations of NRG lead to
glia and Schwann cells; when crest cells form a ganglion, the NRG they produce accumulates
NRG is produced by
migrating neural crest cells
Differentiation is determined intrinsically mostly in the ___
head region (rostral)
Differentiation is determined extrinsically ___
everywhere but the head
What is the rostral migratory stream?
RMS is the migration of new neural stem cells rostrally into the olfactory bulb
___ neurons can be influenced by environmental factors
Young (axon isn’t present)
___ neurons CANNOT be influenced by environmental factors
Old (axon is present)
Order of ‘plates’ in the spinal cord (dorsal to ventral)
Roof plate, Alar plate, Basal plate, Floorplate
Main takeaway of the Tsai paper
Shh gradient determines different homeodomain TF expressions that cross-repress each other to determine tissue boundaries; boundaries are sharpened by transcriptionally unique domains and differential cell-adhesion
GFAP is a marker for
neural stem cells
Temporal order of retinal development
Cones > Rods > Glia
Golgi epithelial cells aka ___ are located in the ___
Bergmann Glial cells are located in the cerebellar cortex
Shh gradient in the spinal cord
High medial, low lateral
radial fibers from glia act as
migratory routes for neural cells
Purkinje cells are generated at ___
the ventricular surface of the cerebellum
Granule cells migrate along ___
the golgi epithelial cell processes (aka Bergmann glia)
