OCCTH 585 Neuro UPDATED Exam
Questions and CORRECT Answers
Information flows through neurons from ____ to ____ in the neuron - CORRECT
ANSWER - dendrite; axon
_____ bring a cell to threshold while _____ bring a cell further from threshold - CORRECT
ANSWER - EPSPs; IPSPs
What 3 main things is neuroplasticity capable of? - CORRECT ANSWER - - changing the
properties of neurotransmission
- changes in cell properties
- structural/ anatomical changes of cells
How does neuroplasticity change the properties of neurotransmission? (2) - CORRECT
ANSWER - - change in transmitter size
- change in PSP size or shape
How does neuroplasticity change the properties of cells? (3) - CORRECT ANSWER --
size and shape
- electrical properties (resistance)
- "leakiness" of membrane
What is unmasking? - CORRECT ANSWER - 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? - CORRECT ANSWER - 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? - CORRECT ANSWER - 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? - CORRECT ANSWER - more stimulation; higher
representation is driven by high rates of APs
What are the 6 mechanisms of collateral sprouting? - CORRECT ANSWER - - growth of
new bits
- requires time
- 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? - CORRECT ANSWER - 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? -
CORRECT ANSWER - neurotrophin (released by dendritic spines through APs)
What are chemoattractants? - CORRECT ANSWER - neurotrophins and other chemical
signals that signal to a neuron to grow their collaterals in that direction
What are chemorepellants? - CORRECT ANSWER - chemical signals that signal to a
neuron to grow their collaterals away from that direction
, What structures release chemoattractants and chemorepellants? - CORRECT ANSWER -
guide cells
What is a growth cone? - CORRECT ANSWER - 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? - CORRECT ANSWER - 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
____________________ - CORRECT ANSWER - growth cone collapse; growth of
filipodia off growth of different spots of the neuron
Where are new neurons produced? (3) - CORRECT ANSWER - - subventricular zone
(olfactory)
- dentrate gyrus of hippocampus (memory)
- Cerebral cortex
What are neurons and neurogenesis' roles in learning and memory? (3) - CORRECT
ANSWER - - undergo synaptic plasticity to retain memory
- can become "locked" for longterm memory
- can be replaced to allow new learning
___-___% of neurons in the hippocampus are replaced _____ - CORRECT ANSWER -
20-25%; monthly
What types of cells can stem cells turn into? - CORRECT ANSWER - - oligodendrocyte
- astrocyte
Questions and CORRECT Answers
Information flows through neurons from ____ to ____ in the neuron - CORRECT
ANSWER - dendrite; axon
_____ bring a cell to threshold while _____ bring a cell further from threshold - CORRECT
ANSWER - EPSPs; IPSPs
What 3 main things is neuroplasticity capable of? - CORRECT ANSWER - - changing the
properties of neurotransmission
- changes in cell properties
- structural/ anatomical changes of cells
How does neuroplasticity change the properties of neurotransmission? (2) - CORRECT
ANSWER - - change in transmitter size
- change in PSP size or shape
How does neuroplasticity change the properties of cells? (3) - CORRECT ANSWER --
size and shape
- electrical properties (resistance)
- "leakiness" of membrane
What is unmasking? - CORRECT ANSWER - 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? - CORRECT ANSWER - 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? - CORRECT ANSWER - 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? - CORRECT ANSWER - more stimulation; higher
representation is driven by high rates of APs
What are the 6 mechanisms of collateral sprouting? - CORRECT ANSWER - - growth of
new bits
- requires time
- 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? - CORRECT ANSWER - 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? -
CORRECT ANSWER - neurotrophin (released by dendritic spines through APs)
What are chemoattractants? - CORRECT ANSWER - neurotrophins and other chemical
signals that signal to a neuron to grow their collaterals in that direction
What are chemorepellants? - CORRECT ANSWER - chemical signals that signal to a
neuron to grow their collaterals away from that direction
, What structures release chemoattractants and chemorepellants? - CORRECT ANSWER -
guide cells
What is a growth cone? - CORRECT ANSWER - 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? - CORRECT ANSWER - 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
____________________ - CORRECT ANSWER - growth cone collapse; growth of
filipodia off growth of different spots of the neuron
Where are new neurons produced? (3) - CORRECT ANSWER - - subventricular zone
(olfactory)
- dentrate gyrus of hippocampus (memory)
- Cerebral cortex
What are neurons and neurogenesis' roles in learning and memory? (3) - CORRECT
ANSWER - - undergo synaptic plasticity to retain memory
- can become "locked" for longterm memory
- can be replaced to allow new learning
___-___% of neurons in the hippocampus are replaced _____ - CORRECT ANSWER -
20-25%; monthly
What types of cells can stem cells turn into? - CORRECT ANSWER - - oligodendrocyte
- astrocyte
