Bio 324 Lecture 8

Front 1

Neural plate and neural tube derived from:

Back 1

embryo ectoderm

Front 2

Neurulation occurs~ __ days after conception?

Back 2

22

Front 3

What develops into the CNS?

Back 3

Neural Tube

Front 4

What develops into the PNS?

Back 4

Neural crest

Front 5

Define anencephaly

Back 5

anterior neural tube defects

Front 6

Define spina bifida

Back 6

posterior neural tube defects

Front 7

The rostal end of the neural tube differentiates into 3 primary brain vesicles. Name them:

Back 7

Prosencephalon
Mesencephalon
Rhombencephalon

Front 8

Differentiation of the prosencephalon develops three new vesicles:

Back 8

Telencephalon
Diencephalon
Optic Vesicles

Front 9

Further differentiation of the telencephalon include:

Back 9

many structures of cerebrum (cortex, corpus collosum, internal capsule)

Front 10

Further differentiation of the diencephalon include:

Back 10

thalamus and hypothalamus

Front 11

Further differentiation of the optic vescicles include:

Back 11

optic nerve and retina

Front 12

What separates the telencephalon and diencephalon?

Back 12

Ventricles

Front 13

Mesencephalon further differentiates into:

Back 13

Tectum, Tegmentum, cerebral aqueduct

Front 14

The tectum differentiates into two structures:

Back 14

superior colliculus & infereior colliculus

Front 15

The superior colliculus is involved with:

Back 15

vision

Front 16

The inferior colliculus is involved with

Back 16

audition (hearing)

Front 17

The tegmentum contains two areas:

Back 17

substantia nigra and red nucleus (motor control)

Front 18

What does the cerebral aqueduct do?

Back 18

Connects the 3rd and 4th ventricle

Front 19

Rhombencephalon structure differentiates into 3 main structures:

Back 19

cerebellum, pons, & medulla

Front 20

The cerebellum and pons make up the:

Back 20

metencephalon

Front 21

The medulla develops from the caudal half called the:

Back 21

myelencephalon

Front 22

The CSF-filled tube of the hindbrain becomes:

Back 22

The fourth ventricle which is continuous with the cerebral aqueduct of the midbrain and continuous with the SC

Front 23

The caudal end of the neural tube develops into:

Back 23

The spinal cord

Front 24

Wiring of the visual system:
(Very precise)

Back 24

Retina- partial decussation at optic chiasm- lateral geniculate nucleus-
Striate cortex (17)- Layer IV

Front 25

General steps in wiring of the brain:

Back 25

neurogenesis-->migration-->differentiation-->neurite pathfinding

Front 26

coritical neural stem cells are located near:

Back 26

lateral ventricles

Front 27

Telencephalon has 2 layers. ______ near the pial layer and ______ near the ventricular surface.

Back 27

marginal zone; ventricular zone

Front 28

The steps in cell proliferation:

Back 28

1) Cell extends process that reaches toward pia
2) Nucleus migrates & replicates
3) nucleus migrates back down
4) cell retracts its arm from pia surface
5) Cell division

Front 29

If cell divides vertically:

Back 29

2 cells remain on ventricular zone for further cell division

Front 30

If cell divides horizontally:

Back 30

one cell remains on ventricular zone and one migrates towards cortex

Front 31

What kind of division of cells predominates during early development?

Back 31

vertical - to expand population of precursor cells

Front 32

What kinds of division of cells predominates during later development?

Back 32

horizontal; migrating cells able to differentiate into neurons or glia

Front 33

Migrating Cell Fate is Determined by a Combination of Factors:

Back 33

Location within ventricular zone, age of precursor cell, environment it is exposed to

Front 34

Neuroblasts Tend to Migrate Along:

Back 34

Radial Glia “Tracks”

Front 35

Explain the process of cerebral cortex development:

Back 35

"Inside-out"; First, Layer VI is formed then Layer V bypasses Layer VI, Then layer IV is formed and bypasses both layers V and VI, etc.

Front 36

Differentiation of cells occurs in what order?

Back 36

Neuroblasts to Neurons, then astrocytes, then oligodendrocytes

Front 37

Differentiation is controlled by:

Back 37

genes and environment

Front 38

Explain Reelin mutation:

Back 38

Cortical Neurons get to the cortical subplate and are unable to pass so they pile up beneath the subplate

Front 39

Marginal zone cells help to establish:

Back 39

cortical cytoarchitecture by secreting chemoattractant or chemorepellant

Front 40

What happens with the External Cue Semaphorin 3A Secreted by Marginal Zone Cells?

Back 40

Attracts dendrites and repels axons- helps give pyramidal cells characteristic shape

Front 41

Semaphorin binds to what receptors? What kind of receptors are these?

Back 41

Plexin; G-protein coupled receptor

Front 42

Three general steps in neurite target pathfinding:

Back 42

1) pathway selection
2) target selection
3) address selection

Front 43

The growing tip of a neurite is called a:

Back 43

Growth cone

Front 44

What does the growth cone do?

Back 44

"sample" the environment; grows towards chemoattractive substrates

Front 45

Ex. of axon growth: The axon has special surface molecules called interins that bind to:

Back 45

laminin

Front 46

Neighboring Axons Often “Piggy Back” On Each Other
In fasciculated bundles mediated by:

Back 46

Neural Cell Adhesion Molecules (NCAM’s).

Front 47

Chemoattractant _____ and chemorepellant _____ help guide growth of axons.

Back 47

netrin; slit

Front 48

What is the slit receptor that is upregulated once the axon crosses the midline?

Back 48

Robo

Front 49

What is released from Oligodendrocytes upon injury?

Back 49

Nogo protein

Front 50

Nogo receptor signals through G-protein Rho (and kinase ROCK) to:

Back 50

inhibit actin/filipodia

Front 51

What is the first step in the formation of a CNS synapse when neuronal dendrites are seeking innervation?

Back 51

Filopodia are continually being formed and retracted

Front 52

Steps of formation of a CNS synapse:

Back 52

1) filopodium contacts an axon
2) recruitment of synaptic vesicle & active zone protein in the presynaptic membrane
3) NT receptors accumulate postsynaptically

Front 53

Postsynaptic Receptor Clustering at the Neuromuscular Junction
is mediated by

Back 53

Agrin

Front 54

Agrin released from presynapse binds to:

Back 54

receptor muscle specific kinase (MuSK)

Front 55

MuSK stimulates Rapsyn to:

Back 55

cluster ACh receptors

Front 56

Nearly __% of All Synapses are Eliminated During Development

Back 56

50

Front 57

Postsynaptic AChR loss precedes:

Back 57

the withdrawal of the axon branch

Front 58

Blocking a subset of receptors with _______________ can also stimulate synapse elimination.

Back 58

alpha-bungarotoxin (Krait snake venom)