OCCTH 585 Neuro Exam Study Set 2| Questions
with Complete Answers
When a neuron has vacant real estate, this space will emit a chemical signal and nearby
cells will begin to form synapses towards those vacancies, what is this process called? -
✔✔collateral sprouting
Provide characteristics of collateral sprouting - ✔✔- requires time to grow new tissue
- may or may not fill vacant space in the nervous sytem
- is activity dependent (more active neurons= more collaterals)
- produces functional changes as they provide more inputs leading to domination of a
cell
Neurogenesis - ✔✔growth of new neurons
T/F: Adults can't generate new neurons in the central nervous system. Explain -
✔✔False. Adults can generate new neurons in very limited anatomical regions such
as the hippocampus, lateral ventricle, and cortex
How are neurons involved in learning and memory - ✔✔we change the structure of
synapses to retain memory and go through new learning when we want to forget
memories
- cells only live for a couple months before they get turned over
Is it possible to use neurogenesis for long term neurological recovery? - ✔✔Not yet.
Neurogenesis happens in a fixed pattern and cells go through a lifetime of learning and
experience to get them to where they are. It would be difficult to take a generic cell and
,plop it into a system that requires it to do a specific task. May also cause chaos to the
system
Why are we unable to grow collaterals across a great distance? - ✔✔the farther from
a target you get, the more diffused and diluted the chemical signals get making it
unnoticeable after a certain point. There are also various barriers and obstacles that get
in the way.
T/F a neuron must be active for collateral sprouting to occur. Defend your answer -
✔✔True. The cell must be able to take up the chemical being released by the vacant
space and it will only achieve this when an AP occurs.
(blank) are released from (blank) to stabilize the position of a synapse -
✔✔neurotrophins; dendritic spine
How does a dendritic spine that finds a synapse closer to the cell body behave? -
✔✔Since it's closer to the cell body it will ahve a stronger E/IPSP and reduced
likelihood of the current leaking out
when a neuron emits growth cues, why doesn't every axon grow towards that neuron?
Why do some repel? - ✔✔axons that respond to the growth cue have the specific
receptor molecule that enables them to read and receive that growth cue
axons that repel from the growth cue have growth repellent receptors that tell them to
grow away from the target
Describe growth cones - ✔✔used to find chemical signals while axons are growing.
They will continue along their path, extending and retracting their lamellipodia as they
search for the signal and ignore neurons that are going to different targets
, a type of cell that will turn on then turn off once the axon has reached it and continue
this way along the path until the axon has reached its target - ✔✔guide cells
How does a guide cell know when to turn on and off? - ✔✔Internal clocks will inform
a cell when it's the right time to turn on/off. When they're off the cells will be
unresponsive to growth
When cells are not supposed to grow in an area what causes the growth cone to
collapse? Does this lead to a full collapse of the growth cone? - ✔✔growth inhibitors;
no, the growth cone will continue to grow past and on the opposite side of the growth
inhibitor
Is axonal growth possible in the mature CNS? - ✔✔yes, however since there's no
growth cues or guide cells, collateral sprouting is limited to its local area
What 7 steps does a neuron go through following injury? - ✔✔1. terminal
degeneration
2. Wallerian degeneration
3. Myelin debris
4. Macrophage infiltration
5. Chromatolysis
6. Retraction of synaptic terminals
7. Degeneration
collapse of the synaptic vesicles and degradation of synaptic terminals is called: -
✔✔terminal degeneration
with Complete Answers
When a neuron has vacant real estate, this space will emit a chemical signal and nearby
cells will begin to form synapses towards those vacancies, what is this process called? -
✔✔collateral sprouting
Provide characteristics of collateral sprouting - ✔✔- requires time to grow new tissue
- may or may not fill vacant space in the nervous sytem
- is activity dependent (more active neurons= more collaterals)
- produces functional changes as they provide more inputs leading to domination of a
cell
Neurogenesis - ✔✔growth of new neurons
T/F: Adults can't generate new neurons in the central nervous system. Explain -
✔✔False. Adults can generate new neurons in very limited anatomical regions such
as the hippocampus, lateral ventricle, and cortex
How are neurons involved in learning and memory - ✔✔we change the structure of
synapses to retain memory and go through new learning when we want to forget
memories
- cells only live for a couple months before they get turned over
Is it possible to use neurogenesis for long term neurological recovery? - ✔✔Not yet.
Neurogenesis happens in a fixed pattern and cells go through a lifetime of learning and
experience to get them to where they are. It would be difficult to take a generic cell and
,plop it into a system that requires it to do a specific task. May also cause chaos to the
system
Why are we unable to grow collaterals across a great distance? - ✔✔the farther from
a target you get, the more diffused and diluted the chemical signals get making it
unnoticeable after a certain point. There are also various barriers and obstacles that get
in the way.
T/F a neuron must be active for collateral sprouting to occur. Defend your answer -
✔✔True. The cell must be able to take up the chemical being released by the vacant
space and it will only achieve this when an AP occurs.
(blank) are released from (blank) to stabilize the position of a synapse -
✔✔neurotrophins; dendritic spine
How does a dendritic spine that finds a synapse closer to the cell body behave? -
✔✔Since it's closer to the cell body it will ahve a stronger E/IPSP and reduced
likelihood of the current leaking out
when a neuron emits growth cues, why doesn't every axon grow towards that neuron?
Why do some repel? - ✔✔axons that respond to the growth cue have the specific
receptor molecule that enables them to read and receive that growth cue
axons that repel from the growth cue have growth repellent receptors that tell them to
grow away from the target
Describe growth cones - ✔✔used to find chemical signals while axons are growing.
They will continue along their path, extending and retracting their lamellipodia as they
search for the signal and ignore neurons that are going to different targets
, a type of cell that will turn on then turn off once the axon has reached it and continue
this way along the path until the axon has reached its target - ✔✔guide cells
How does a guide cell know when to turn on and off? - ✔✔Internal clocks will inform
a cell when it's the right time to turn on/off. When they're off the cells will be
unresponsive to growth
When cells are not supposed to grow in an area what causes the growth cone to
collapse? Does this lead to a full collapse of the growth cone? - ✔✔growth inhibitors;
no, the growth cone will continue to grow past and on the opposite side of the growth
inhibitor
Is axonal growth possible in the mature CNS? - ✔✔yes, however since there's no
growth cues or guide cells, collateral sprouting is limited to its local area
What 7 steps does a neuron go through following injury? - ✔✔1. terminal
degeneration
2. Wallerian degeneration
3. Myelin debris
4. Macrophage infiltration
5. Chromatolysis
6. Retraction of synaptic terminals
7. Degeneration
collapse of the synaptic vesicles and degradation of synaptic terminals is called: -
✔✔terminal degeneration
