OCCTH 585 Neuro Questions And Answers
Information flows through neurons from ____ to ____ in the neuron dendrite; axon
_____ bring a cell to threshold while _____ bring a cell further from threshold EPSPs;
IPSPs
What 3 main things is neuroplasticity capable of? - changing the properties of
neurotransmission
- changes in cell properties
- structural/ anatomical changes of cells
How does neuroplasticity change the properties of neurotransmission? (2) - change in
transmitter size
- change in PSP size or shape
How does neuroplasticity change the properties of cells? (3) - size and shape
- electrical properties (resistance)
- "leakiness" of membrane
, OCCTH 585 Neuro Questions And Answers
What is unmasking? when an injury, event, or illness eliminates the inputs that a neuron
most commonly responds to (i.e. blue --> blue region of brain), the neuron will become more
responsive to the other inputs on the neuron (i.e. yellow --> yellow region of brain) and that new
representation will increase; is immediate, involves exposure of pre-existing synapses, and
creates functional changes in the cell
What is dendritic pruning? when dendrites with no active synapses are retracted to reduce
the amount of resources wasted to keep those useless dendrites alive; changes cellular properties
(size and shape) and creates as 'loss of real estate', decreases energy expenditure
What is collateral sprouting? when neurons sprout new synapses on bare dendrites (either
after pruning of dead synapses or less used working ones) leading the cell to become more
responsive to those new inputs
What can lead to collateral sprouting? more stimulation; higher representation is driven by
high rates of APs
What are the 6 mechanisms of collateral sprouting? - growth of new bits
- requires time
, OCCTH 585 Neuro Questions And Answers
- fill vacancy OR push less used synapses out of the way
- activity dependent
- produces functional changes
Do neurons have to be close to the "free real estate" in order to make new collaterals? Do they
need to already be involved with it? no, the closest ones will usually get there first, but the
axons can grow out 1-2cm to form a connection (any further = stuff in the way, would take too
long and die); no
What signals to other neurons that there is space to form new collaterals and guides them to it?
neurotrophin (released by dendritic spines through APs)
What are chemoattractants? neurotrophins and other chemical signals that signal to a
neuron to grow their collaterals in that direction
What are chemorepellants? chemical signals that signal to a neuron to grow their
collaterals away from that direction
What structures release chemoattractants and chemorepellants? guide cells
, OCCTH 585 Neuro Questions And Answers
What is a growth cone? a specialized structure at the end of the axon that has filopodia
that branch out in multiple directions to look for chemoattractive and chemorepellant signals
Are neurons always responsive to guidance molecules? no, they are time-locked based on
the developmental clock of the embryo; some guidance molecules can be both a chemoattractant
and a chemorepellant depending on the embryo's current stage of development
A large chemorepellant signal can lead to ____ ____ ____; exposure can also signal
____________________ growth cone collapse; growth of filipodia off growth of different
spots of the neuron
Where are new neurons produced? (3) - subventricular zone (olfactory)
- dentrate gyrus of hippocampus (memory)
- Cerebral cortex
What are neurons and neurogenesis' roles in learning and memory? (3) - undergo synaptic
plasticity to retain memory
- can become "locked" for longterm memory
Information flows through neurons from ____ to ____ in the neuron dendrite; axon
_____ bring a cell to threshold while _____ bring a cell further from threshold EPSPs;
IPSPs
What 3 main things is neuroplasticity capable of? - changing the properties of
neurotransmission
- changes in cell properties
- structural/ anatomical changes of cells
How does neuroplasticity change the properties of neurotransmission? (2) - change in
transmitter size
- change in PSP size or shape
How does neuroplasticity change the properties of cells? (3) - size and shape
- electrical properties (resistance)
- "leakiness" of membrane
, OCCTH 585 Neuro Questions And Answers
What is unmasking? when an injury, event, or illness eliminates the inputs that a neuron
most commonly responds to (i.e. blue --> blue region of brain), the neuron will become more
responsive to the other inputs on the neuron (i.e. yellow --> yellow region of brain) and that new
representation will increase; is immediate, involves exposure of pre-existing synapses, and
creates functional changes in the cell
What is dendritic pruning? when dendrites with no active synapses are retracted to reduce
the amount of resources wasted to keep those useless dendrites alive; changes cellular properties
(size and shape) and creates as 'loss of real estate', decreases energy expenditure
What is collateral sprouting? when neurons sprout new synapses on bare dendrites (either
after pruning of dead synapses or less used working ones) leading the cell to become more
responsive to those new inputs
What can lead to collateral sprouting? more stimulation; higher representation is driven by
high rates of APs
What are the 6 mechanisms of collateral sprouting? - growth of new bits
- requires time
, OCCTH 585 Neuro Questions And Answers
- fill vacancy OR push less used synapses out of the way
- activity dependent
- produces functional changes
Do neurons have to be close to the "free real estate" in order to make new collaterals? Do they
need to already be involved with it? no, the closest ones will usually get there first, but the
axons can grow out 1-2cm to form a connection (any further = stuff in the way, would take too
long and die); no
What signals to other neurons that there is space to form new collaterals and guides them to it?
neurotrophin (released by dendritic spines through APs)
What are chemoattractants? neurotrophins and other chemical signals that signal to a
neuron to grow their collaterals in that direction
What are chemorepellants? chemical signals that signal to a neuron to grow their
collaterals away from that direction
What structures release chemoattractants and chemorepellants? guide cells
, OCCTH 585 Neuro Questions And Answers
What is a growth cone? a specialized structure at the end of the axon that has filopodia
that branch out in multiple directions to look for chemoattractive and chemorepellant signals
Are neurons always responsive to guidance molecules? no, they are time-locked based on
the developmental clock of the embryo; some guidance molecules can be both a chemoattractant
and a chemorepellant depending on the embryo's current stage of development
A large chemorepellant signal can lead to ____ ____ ____; exposure can also signal
____________________ growth cone collapse; growth of filipodia off growth of different
spots of the neuron
Where are new neurons produced? (3) - subventricular zone (olfactory)
- dentrate gyrus of hippocampus (memory)
- Cerebral cortex
What are neurons and neurogenesis' roles in learning and memory? (3) - undergo synaptic
plasticity to retain memory
- can become "locked" for longterm memory
