CHAPTER 10 Flashcards
(39 cards)
Neural crest cells are derived from the ectoderm, it
is important that it has been called the “____________”.
fourth germ
layer
- a population of multipotent progenitor cells
that can produce tissues that emerges from
the dorsal neural tube during early
development. - has the capacity to differentiate into
particular cell types associated with multiple
cell lineages
Neural crest
_________ is the process by which
neural crest cells are specified from the
neuroectoderm
Neural crest induction
Stages in the Specification of Neural Crest Cells
• NEURAL PLATE INDUCTIVE SIGNALS: BMPs,
Wnts, FGFs, Notch»_space;
• NEURAL PLATE BORDER
SPECIFIERS: D115, Pax3/7»_space;
• NEURAL CREST
SPECIFIERS: Fox D3, Twist, Snail»_space;
• NEURAL
CREST EFFECTORS: MITF, Rho GTPases, Kit, Ret
● _____________
(early-migrating NCC) - come around the
neural tube and start coming downward
THROUGH the somite.
● __________
(late-migrating NCC) - around the somite
on the outer rim.
VENTRAL-LATERAL MIGRATION
DORSAL-LATERAL MIGRATION
The ______ is largely the product, and the
evolution of jaws, teeth, and facial cartilage
occurs through changes in the placement of
these cells
head
Neural crest cells from the vagal and sacral
regions form the _______ of the gut
tube and control ________
enteric ganglia
intestinal peristalsis
Only these particular neural crest cells
generate the endothelium of the aortic arch
arteries and the septum between the aorta
and the pulmonary artery
Cardiac neural crest cell
The ___________ perform one
of the longest migration because they are
chasing a moving target—the caudal most,
or distal extent of the growing gut.
enteric neural crest cells
________, whose axons travel from
the spinal cord to a specific muscle.
Motor neurons
Two main migratory paths of trunk neural crest cells
Ventral lateral migration
Dorsal lateral migration
______ whose axons must cross the midline plane of the embryo to innervate targets on the opposite side of the central nervous system
Commissural neurons
The ____, where axons originating in the retina must find their way back into the brain
Optic system
Three steps of axonal specificity
Pathway selection
Target selection
Address selection
The axons travel along a route that leads to a particular region of the embryo.
Pathway selection
The axons, once they reach the correct area, recognize and bind to a set of cells with which they may form stable connections.
Target selection
The initial patterns are refined such that each asxom binds to a small subset of its possible targets.
Address selection
Neurons at the ventrolateral margin of the vertebrate neural tube become ________, and one of their first steps toward maturation involves target specificity.
motor neurons
The axonal growth toward the dorsal muscle is because Lim1 induces the expression of _____, which is the receptor for the chemorepellent protein ephrin A5 that is made in the ventral part of the limb bud.
EphA4
Motor neurons seek their targets through _____ “______”
intrinsic programs
The ephrins and the semaphorins, are most well-known membrane proteins (but not exclusively) for their role as ________ during the patterning of axonal anatomy.
repellent guidance cues
The proteins of the semaphorin-3 family, also known as _______, are secreted proteins and collapse the growth cones of axons originating in the dorsal root ganglia.
collapsins
Types of commissural neurons
Shh
Netrin
Slit and Robo
______ is made in and secreted from the floor plate and is distributed in a concentration gradient that is high ventrally and low dorsally
Shh
