Stem Cells II

Question 1

Olfactory apical neuron end functions as

Answer 1

Detects external stimulus which changes membrane potential (depolarizes, generates AP)

Question 2

Olfactory neuron basal end functions as

Answer 2

Synapse with neurons that relay sensory inforation

Question 3

Olfactory neurons are bipolar neurons with dendrite facing extracellular environment. T/F?

Answer 3

True

Question 4

What type of receptor is the olfactory receptor?

Answer 4

G-protein coupled receptor

Question 5

T/F: Free surfaces of cilia have odorant receptors proteins

Answer 5

True

Question 6

Each neuron expresses only _ odorant receptor gene

Answer 6

1

Question 7

Having only 1 odorant receptor gene causes cell to respond to only 1 class of odorant. T/F?

Answer 7

True

Question 8

What is the mechanism for olfactory sensory neurons

Answer 8

Ligand binds to olfactory receptor-> activates olfactory receptor-> activates intracellular (heterotrimeric) G protein Golf-> activates adenyl cyclase-> cAMP produced-> ion channels open in plasma membrane->influx of Na+ and Ca2+ into cell-> neuron depolarizes->AP generated and converges into olfactory bulb

Question 9

Phosphodiesterase and Ca2+ turns off what?

Answer 9

Olfactory receptor

Question 10

What is the relay station for APs

Answer 10

Glomeruli located in olfactory bulbs

Question 11

Neural stem cells reside in:

Answer 11

Basal cells

Question 12

Loss of smell is linked to

Answer 12

Neurodegenerative disorders and aged individuals

Question 13

Where are stem cells are found, produce new stem cells, migrate to olfactory bulb where differentiate to olfactory neurons

Answer 13

Ventricles of forebrain

Question 14

Learning and memory formation, continuous turnover of cells associated with plasticity of adult brain, about 1400 fresh neurons are generated each day

Answer 14

Hippocampus

Question 15

What are neurospheres

Answer 15

Clusters of neural stem cells, neural cells (neurons), and glial cells

Question 16

T/F: sensory cells are well conserved throughout evolution

Answer 16

True

Question 17

Sensory cells present in the sensory epithelium act as __, converting signlas from the environment into an __ form that can be interpreted by the CNS

Answer 17

Transducers, electrical form

Question 18

What is the function of a sensory cell’s basal end?

Answer 18

Makes a synapse with neurons that relay the sensory info

Question 19

An olfactory neuron is a bipolar neuron. What are the 2 parts and their function?

Answer 19

Dendrite facing the extracellular environment and an axon that travels along the olfactory nerve to olfactory bulb in brain

Question 20

What protrudes from olfactory neuron’s dendrites?

Answer 20

Hair like cilia

Question 21

What are the supporting cells of olfactory neurons function?

Answer 21

Present in between the neurons to hold in place and keep separate

Question 22

T/F: basal cells in the epithelium-cells in contact with the basal lamina

Answer 22

True

Question 23

How many odorant receptor genes in a dog compared to a human

Answer 23

1000 in a dog and 350 in a human

Question 24

What is recognized by the odorant receptor?

Answer 24

Structural features

Question 25

Are all olfactory neurons response uncommon?

Answer 25

No, they are a common mechanism

Question 26

How many glomeruli/bulb in a mouse brain?

Answer 26

1800

Question 27

Olfactory neuron’s axons converge on the same:

Answer 27

Glomerulus

Question 28

What generates replacements for lost olfactory neurons?

Answer 28

Neural stem cells

Question 29

What cells in contact with the basal lamina divide and differentiate into olfactory neurons?

Answer 29

Basal stem cells

Question 30

How do odorant receptor proteins help in regeneration of olfactory neurons?

Answer 30

Odorant receptor proteins help in AXONAL GUIDANCE and allow growth cone to migrate to and establish CONNECTION WITH CORRECT GLOMERULUS in olfactory bulb

Question 31

Regeneration of olfactory receptor cells in one of the only few instances of:

Answer 31

Adult neurogenesis in the CNS

Question 32

Parkinson’s disease, reduced sense of smell precedes:

Answer 32

Clinical symptoms

Question 33

Alzheimer’s disease severity correlates with:

Answer 33

Degree of loss of olfaction

Question 34

Why is the CNS the most difficult to reconstruct?

Answer 34

Adult brain and spinal cord have LITTLE CAPACITY TO SELF-REPAIR OR REGENERATE

Question 35

Stem cells in brain are found where:

Answer 35

Ventricles of forebrain and hippocampus

Question 36

What is important about planaria?

Answer 36

Is a freshwater flatworm that has extraordinary capacity to regenerate. Ie when starved reduces cell number while maintaining body proportions. Has cycles of de-growth and growth w/o har to survival or fertility

Question 37

What is important of neoblasts?

Answer 37

20% of planaria’s cells are neoblasts which are stem cells. Can re-uptake dying cells in process called cell cannibalism

Question 38

How does a newt accomplish regeneration?

Answer 38

Differentiated muscle cells de-differentiate and become embryonic cells