Deck 3: Neurogenesis and Migration

Question 1

What is the term for the phenomenon in which a gene plays a role in the development of several different, apparently unrelated functions?

A) Redundancy
B) Pleiotropy
C) Multipotency
D) Neurogenesis

Answer 1

B

Question 2

Because noggin, chordin, and follistatin all play a role in neural plate differentiation, there is _______ of gene effects.

A) redundancy
B) pleiotropy
C) silencing
D) automation

Answer 2

A

Question 3

The tangled threads of chromosomes that are in the process of separating are called

A) pia mater.
B) mitotic figures.
C) neuroblasts.
D) glia.

Answer 3

B

Question 4

In neural tube development, a neuroblast may divide _______ to produce two neuroblasts.

A) asymmetrically
B) only once
C) symmetrically
D) pleiotropically

Question 5

In the developing neural tube, mitosis occurs almost exclusively near the

A) meninges.
B) pia mater.
C) ventricular zone.
D) rhombomeres.

Question 6

Astrocytes can be distinguished from neurons because only astrocytes express

A) mitotic figures.
B) 5-bromo-2-deoxyuridine.
C) beta-galactosidase.
D) glia fibrillary acid protein.

Question 7

In the developing cerebral cortex, the _______ is the layer of postmitotic cells that expands to form cortical layers II-IV.

A) cortical plate
B) molecular layer
C) ventricular zone
D) intermediate zone

Question 8

In the cerebral cortex, the layer of cells that populate the region just above, but not lining, the ventricular surface is referred to as the

A) intermediate zone.
B) subventricular zone.
C) cortical plate.
D) supraventricular zone.

Question 9

In the cerebral cortex, how does cell division in the ventricular zone differ from that in the subventricular zone?

A) Cells in the ventricular zone can only divide asymmetrically.
B) Cells in the ventricular zone can only divide symmetrically.
C) Cells in the ventricular zone can divide symmetrically or asymmetrically.
D) Cells in the ventricular zone divide throughout life.

Question 10

Which molecule, used to determine the birthdate of a cell, is especially useful because immunohistochemistry can be applied to identify it safely and efficiently?

A) Thymidine
B) Fos
C) GFAP
D) BrDU

Question 11

Immunohistochemistry is the process of using _______ to visualize a particular molecule.

A) antibodies
B) epitopes
C) autoradiography
D) thymidine

Question 12

In the developing neural tube, migrating postmitotic cells shinny outward on _______ toward their destination.

A) ganglionic eminences
B) radial glia
C) astrocytes
D) Bergmann glia

Question 13

Neurons that develop from the ganglionic eminences migrate _______ along glia and become _______.

A) radially; glial cells
B) tangentially; glial cells
C) radially; basal ganglia
D) tangentially; basal ganglia

Question 14

Researchers injected a DNA marker into rhesus monkeys at different prenatal stages of development, let them grow up, and then looked at the neocortex neurons. They found that, depending on when during development they injected their DNA marker, the labeled neurons would be located in a different layer of the cortex with the most recently labeled ones located in layer II. What do these results suggest?

A) Cortical neurons settle into the six cortical layers in a random manner.
B) Cortical neurons settle into the first available spot in the cortex they find.
C) Cortical neurons settle in an inside-out manner, with neurons first populating layer VI.
D) Cortical neurons settle in an outside-in manner, with neurons first populating layer II.

Question 15

In adults, newly born interneurons in the olfactory bulb arise from cells in the

A) olfactory epithelium.
B) subgranular zone.
C) subventricular zone.
D) ganglionic eminences.

Question 16

If BrDU-stained neurons are found in the dentate gyrus, from where did they originate?

A) Olfactory epithelium
B) Subgranular zone
C) Subventricular zone
D) Ganglionic eminences

Question 17

In neural crest cell migration, cells that stop just short of the somites will develop into neurons of the

A) dorsal root ganglia.
B) autonomic ganglia.
C) adrenal medulla.
D) pigment epithelia.

Question 18

Neural crest cells from the thoracic and lumbar regions will form the

A) parasympathetic ganglia.
B) sympathetic ganglia.
C) adrenal medulla.
D) pigment epithelia.

Question 19

In order to migrate to their destinations, neural crest cells must move though the _______ by secreting _______.

A) subventricular zone; cell adhesion molecules
B) subventricular zone; metalloproteases
C) basal lamina; cell adhesion molecules
D) basal lamina; metalloproteases

Question 20

What repels migrating neural crest cells?

A) Anterior somites
B) Ephrins
C) Fibronectin
D) Metalloproteases

Question 21

In cerebellar development, neurons in the external granule layer come from

A) the rhombic lip of the pons.
B) the ventricular zone of the lateral ventricle.
C) the rostral migratory stream.
D) shinnying down Bergmann glia.

Question 22

In cerebellar development, the cell bodies of granule neurons migrate along _______ to settle into their adult placement in the _______ granule layer.

A) Bergmann glia; external
B) radial glia; external
C) Bergmann glia; internal
D) fibronectin; internal

Question 23

Abnormal cerebellum development characterized by a missing granule cell layer results from a mutation in which gene?

A) lacZ
B) astrotactin
C) weaver
D) reelin

Question 24

GnRH-releasing neurons in the hypothalamus migrate during development from the

A) olfactory epithelium.
B) subgranular zone.
C) olfactory placode.
D) subventricular zone.

Question 25

To determine what specific cells will end up migrating to the hypothalamus from a point in development just after the telencephalon has formed, the best experimental design would be to use immunohistochemistry directed at

A) BrDU in the hypothalamus.
B) GnRH in the hypothalamus.
C) BrDU in the olfactory placode.
D) GnRH in the olfactory placode.

Question 26

When researchers wanted to know whether mitotic lineage played a role in whether vertebrate neural cells develop into neurons or glia, they infected a single cell with the reporter gene lacZ, which allowed them to track every cell that descended from that one original parent cell. They found that the single infected cell ended up dividing to produce many different types of cells. What do these results suggest?

Question 27

In the developing cerebral cortex, the cortical intermediate zone eventually forms what is called the white matter of the brain. Explain why the white matter appears white.

Question 28

In humans, a late migration of cells to the frontal cortex has been observed after birth and is most prominent during the first few months of life. What is the potential significance of cells settling in various layers of the frontal cortex after birth?

Question 29

If BrDU is injected into an adult rat, and one month later, the rat's brain is examined and found to have BrDU in the nucleus of neurons in the dentate gyrus. What can be concluded about the BrDU-stained neurons?

Question 30

If adult neurogenesis occurs in a certain region of the brain, why might that area not continue to grow larger?

Question 31

Refer to the figure.
Along this portion of the neural tube, which will become the spinal cord, predict the fate of each of the groups of neural crest cells, depicted in blue, orange, yellow and red.

Question 32

Once neural crest cells break free from the neural tube, what specific molecular factor allows them to migrate out in discrete streams rather than in one continuous wave? Name the factor and where it is located, and describe how it influences crest cell migration.

Question 33

Cell adhesion molecules (CAMs) play an important role in neural crest cell migration. Describe how migrating neural crest cells change their expression of two adhesion molecules, and how this change influences their movement at each of the following points along their migration: initially leaving the neural tube, migrating along the pathway toward their target, and settling down at their final target.

Question 34

Refer to the figure.
The figure shows a photomicrograph of the cerebellum of a mouse with a reeler mutation. The granule cells are darkly stained and a representative Purkinje cell is denoted with an arrow. Describe the organization of the Purkinje and granule cells in this mutant mouse compared to a wild-type mouse.

Question 35

Explain the mechanism responsible for why Kallmann syndrome is characterized by two seemingly unrelated symptoms: failure of the pituitary to release gonadotropins at puberty and lack of a sense of smell.