OCCTH 585- Neuro
How do we know the brain is capable of being changed? - Answer- 1. Skill
acquisition: our brain layout must change to allow for the acquisition of new
capabilities
2. nervous system develops as you grow
3. aging: after age 21 we start to lose neurons so the neurons left over will adapt to
pick up the slack
4. Nervous system changes following injury or disease
5. Recovery: the brain will go through neuroplasticity to optimize what it has left
The main communicating cells of the nervous system are: - Answer- neurons
In what ways does neuroplasticity occur? - Answer- 1. change in the properties of
neurotransmission via a change in PSP size or shape and/or a change in the
transmitter released
2. changing the cell properties by changing the size/shape of the cell, it's electrical
properties/resistance and/or leakiness of the membrane
3. structural changes in the cell
Describe the process of unmasking - Answer- the process of exposing present
synapses that were previously silent
You're working on reducing a recent lower limb amputee's phantom limb pain when
they ask you the reason for why they still feel sensation in a limb that is no longer
there. What phenomenon is the likely cause and how would you explain it? - Answer-
They are experiencing unmasking. I would inform them that while they are no longer
getting sensory input from that limb, there are neurons in that cortical area of the
brain that have now been exposed. These neurons receive inputs from other areas
of the body which result in the the sensation felt by the amputated limb.
Describe the process of dendritic pruning - Answer- If a neuron loses inputs from a
cell following disease or injury and the vacant spots are not filled, the dendrites will
begin to retract causing changes to the cell's shape/size and thus its behaviour
compare and contrast unmasking vs dendritic pruning - Answer- unmasking occurs
immediately and results in functional changes to the cells that influence its behaviour
dendritie pruning occurs over time and results in a loss of SA, brain mass, and
changes to the shape/size of the cell which leads to changes in behaviour
Simply put, collateral sprouting is... - Answer- growth of new synapses onto a cell
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? - Answer- collateral sprouting
, Provide characteristics of collateral sprouting - Answer- - 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 - Answer- growth of new neurons
T/F: Adults can't generate new neurons in the central nervous system. Explain -
Answer- 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 - Answer- 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? - Answer- 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? - Answer- 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 -
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 - Answer-
neurotrophins; dendritic spine
How does a dendritic spine that finds a synapse closer to the cell body behave? -
Answer- 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? - Answer- 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 - Answer- 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
How do we know the brain is capable of being changed? - Answer- 1. Skill
acquisition: our brain layout must change to allow for the acquisition of new
capabilities
2. nervous system develops as you grow
3. aging: after age 21 we start to lose neurons so the neurons left over will adapt to
pick up the slack
4. Nervous system changes following injury or disease
5. Recovery: the brain will go through neuroplasticity to optimize what it has left
The main communicating cells of the nervous system are: - Answer- neurons
In what ways does neuroplasticity occur? - Answer- 1. change in the properties of
neurotransmission via a change in PSP size or shape and/or a change in the
transmitter released
2. changing the cell properties by changing the size/shape of the cell, it's electrical
properties/resistance and/or leakiness of the membrane
3. structural changes in the cell
Describe the process of unmasking - Answer- the process of exposing present
synapses that were previously silent
You're working on reducing a recent lower limb amputee's phantom limb pain when
they ask you the reason for why they still feel sensation in a limb that is no longer
there. What phenomenon is the likely cause and how would you explain it? - Answer-
They are experiencing unmasking. I would inform them that while they are no longer
getting sensory input from that limb, there are neurons in that cortical area of the
brain that have now been exposed. These neurons receive inputs from other areas
of the body which result in the the sensation felt by the amputated limb.
Describe the process of dendritic pruning - Answer- If a neuron loses inputs from a
cell following disease or injury and the vacant spots are not filled, the dendrites will
begin to retract causing changes to the cell's shape/size and thus its behaviour
compare and contrast unmasking vs dendritic pruning - Answer- unmasking occurs
immediately and results in functional changes to the cells that influence its behaviour
dendritie pruning occurs over time and results in a loss of SA, brain mass, and
changes to the shape/size of the cell which leads to changes in behaviour
Simply put, collateral sprouting is... - Answer- growth of new synapses onto a cell
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? - Answer- collateral sprouting
, Provide characteristics of collateral sprouting - Answer- - 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 - Answer- growth of new neurons
T/F: Adults can't generate new neurons in the central nervous system. Explain -
Answer- 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 - Answer- 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? - Answer- 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? - Answer- 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 -
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 - Answer-
neurotrophins; dendritic spine
How does a dendritic spine that finds a synapse closer to the cell body behave? -
Answer- 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? - Answer- 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 - Answer- 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
