Lecture 11 - Neurogenesis and Migration II

Question 1

birthdate

Answer 1

time during development when a given cell underwent its final mitosis before differentiating into a neuron or glial cell

Question 2

thymidine

Answer 2

a nucleotide use in the synthesis of DNA

Question 3

why thymidine can be a DNA-specific marker

Answer 3

not used in RNA

Question 4

birth dating cells experiment

Answer 4

1. inject radiolabeled thymidine into pregnant mice (most cells in S-phase)
2. injected thymidine gets depleted from circulation
3. cells that take up the label and stop/ few more dividing will have sufficient radiolabel in their nuclei so that it is easy to detect later when the animal is sacrificed

Question 5

BrdU

Answer 5

synthetic nucleotide that can serve as a substitute for thymidine in synthesis of DNA but can be readily be distinguished from thymidine by use of antibodies

Question 6

antibodies

Answer 6

large, Y-shaped proteins produced by the immune system that recognize and bind to particular shapes in molecules

Question 7

immunohistochemistry

Answer 7

method for detecting particular protein in tissues in which an antibody recognizes and binds to the protein and then chemical methods are used to leave a visual reaction product around each antibody

Question 8

immunohistochemistry process

Answer 8

1. thin tissue slice
2. add antibody directed to BrdU
3. let it sit for a few hours to overnight
4. rinse off antibody
5. IHC or IHF

Question 9

immunohistochemistry

Answer 9

incubate and rinse tissue through a series of solutions to form a visible, colored reaction product under a microscope

Question 10

immunofluorescence

Answer 10

incubate with a fluorophore, rinse and look under a microscope

Question 11

GFAP

Answer 11

structural protein normally expressed in radial glia and astrocytes but not in neurons

Question 12

radial glia

Answer 12

long, slender glial cells that stretch from the ventricular surface to the plial surface in the vertebrate cerebral cortex

Question 13

radial glia guide….

Answer 13

migrating cells

Question 14

cell migration & radial glia

Answer 14

post mitotic cells from VZ latch to radial glia and shinny outward; migrating cell extends a small part of itself along the glial rope, process attaches to the fiber then contracts, pulling the cell body along the line

Question 15

formation of layer 1

Answer 15

molecular layer form above marginal zone

Question 16

cell migration to form neocortex

Answer 16

mitotic cells go below marginal zone and form cortical plate > these cells form layer 6

Question 17

order of migration

Answer 17

layer 6-2

Question 18

intermediate zone

Answer 18

eventually filled with axons, creating the white matter of cortical interior

Question 19

upper cortex experiment: test

Answer 19

inject a DNA marker into rhesus monkey at different prenatal stages of development, then determine where neurons with different birth dates are found in cortex after growing up

Question 20

upper cortex experiment: result

Answer 20

1. earliest born cells settle in either intermediate zone or marginal layer (L1) closest to plial surface
2. injections later in gestation are deepest layer
3. injections at successively later stages of development are progressively higher cortical layers
4. injections 110 days or later are glia and endothelial cells in the cortex but no neurons

Question 21

inside out pattern of development

Answer 21

orderly progression of age of neurons in the cortex

Question 22

tangential route

Answer 22

some neurons don’t migrate straight out along the radial glia but across neighboring radial glia

Question 23

ganglionic eminences

Answer 23

other germinal zones that cells arise from that line lateral ventricles; transient structures in ventral telencephalon

Question 24

medial GE

Answer 24

located in rostral telencephalon

Question 25

lateral GE

Answer 25

located in rostral telencephalon

Question 26

caudal GE

Answer 26

located in posterior telencephalon

Question 27

post mitotic cells from GE zones

Answer 27

contribute interneurons, especially GABAergic neurons to several cortical regions and give rise to neurons in basal ganglia and amygdala

Question 28

late migration

Answer 28

arc of migrating neurons along anterior cingulate cortex just above the corpus callosum

Question 29

arc neurons outcome

Answer 29

become inhibitory interneurons using GABA

Question 30

migration of arc neurons

Answer 30

first move tangentially across radial glia then follow them out settle into various cortical layer

Question 31

arc neurons and neural plasticity

Answer 31

provide additional neural plasticity as the infant learns from social interactions

Question 32

germinal zones that give rise to adult-born neurons

Answer 32

1. olfactory neuroepithelium 2. SVZ 3. sub-granular zone

Question 33

olfactory neuroepithelium

Answer 33

contain cells that continue to divide to provide new olfactory sensory neurons - can be replaced throughout life and may undergo replacement without trauma

Question 34

SVZ

Answer 34

of lateral ventricle, produces cells that migrate rostrally to continuously replace interneurons in the adult olfactory bulb

Question 35

RMS (rostral migratory stream)

Answer 35

a collection of cells that migrate from the anterior horn of the lateral ventricle to the olfactory bulbs in adult mammals (some still divide)

Question 36

astrocytes

Answer 36

guide migration of RMS; form a tunnel surrounding the migrating cells

Question 37

upon arrival to the olfactory bulb

Answer 37

cells differentiate into granular and periglomerular interneurons

Question 38

sub-granular zone

Answer 38

the portion of the dentate gyrus where cells divide in adulthood to contribute new neurons to the overlying granular layer

Question 39

sub-granular zone involved in...

Answer 39

learning and memory

Question 40

evidence for sub-granular zone as learning and memory center

Answer 40

1. animals put into situations where they are expected to learn display more new hippocampal neurons 2. administering radiation or toxins to inhibit neurogenesis interferes with memory functions that are known to rely upon hippocampus 3. neurogenesis appears to slow down in older animals at about the same time or before their learning capacity diminishes

Question 41

derivatives of neural crest

Answer 41

PNS, endocrine and para-endocrine derivatives, pigment cells, facial cartilage/bones, connective tissue

Question 42

neural crest cells found...

Answer 42

alongside the entire rostral-caudal (AP axis) extent of the neural tube

Question 43

what do pharyngeal arches produce?

Answer 43

cartilage, bones, muscles, glands, connective tissue of the face and neck

Question 44

somites

Answer 44

mesodermally derived blocks of cell found on either side of the neural tube

Question 45

somites give rise to...

Answer 45

bone, cartilage, and skin

Question 46

dorsal root ganglia

Answer 46

bipolar neurons receiving sensory information from the periphery and transmitting it to neurons of the dorsal spinal cord

Question 47

autonomic ganglia

Answer 47

collections of neurons outside the CNS, they receive input from the CNS and in turn provides autonomic innervations of various organs in the body

Question 48

sympathetic ganglia

Answer 48

arise exclusively from crest cells in the thoracic and lumbar regions

Question 49

crest cells from cervical and sacral spinal region contribute to...

Answer 49

parasympathetic ganglia

Question 50

adrenal medulla

Answer 50

subset of neural crest cells settle near the aorta and form the inner portion of the adrenal gland, the adrenal medulla that secretes epinephrine when activated by sympathetic fibers

Question 51

pigment epithelia

Answer 51

neural crest cells flow dorsally over the somites eventually differentiate into melanocytes (pigment cells), providing color to the skin