Term
| 3 things we need to make a functioning brain |
|
Definition
1. generate neurons
2. generate connections between neurons
3. refine and adjust the connections to match experience |
|
|
Term
| when is the peak of neurogenesis? how many per minute? |
|
Definition
| before birth: 250,000/minute |
|
|
Term
| what happens after birth and through postnatal life-adulthood for neurogenesis? |
|
Definition
| Most of the refinement and experience-dependent plasticity occurs |
|
|
Term
neurons continue to be generated even in
the adult brain |
|
Definition
|
|
Term
| The function of the brain depends on... |
|
Definition
| precise connectivity (“wiring”) |
|
|
Term
The entire central nervous system develops from an early embryonic
structure called |
|
Definition
|
|
Term
| The neural tube encloses 3 and later 5... |
|
Definition
|
|
Term
| Neurogenesis involves 3 things |
|
Definition
1.cell proliferation,
2. migration
3. differentiation. |
|
|
Term
Two layers (zones) in the neural
tube: |
|
Definition
ventricular zone and
marginal zone |
|
|
Term
5. Stages of cell proliferation in the
neural tube |
|
Definition
(1) process
extension to pial surface; (2)
nucleus migration and DNA
replication; (3) nucleus returns to
ventricular surface; (4) retraction
of process from pial surface; (5)
cell divides in two |
|
|
Term
| after the cell divides in 2 from cell proliferation what are the 2 possibilities that could happen next? |
|
Definition
cell cleaves in
the vertical plane or in the
horizontal plane. |
|
|
Term
| After vertical cleavage... |
|
Definition
daughter
cells both remain in the
ventricular zone and continue to
divide and proliferate. |
|
|
Term
| After horizontal cleavage... |
|
Definition
: two
daughter cells have different
fate; one cell migrates away to
its final position within cortex
and stops dividing; the other cell
remains in the ventricular zone
and continues to divide |
|
|
Term
Different types of neurons and glia arise from the same type of
precursor cells called.. |
|
Definition
|
|
Term
Precursor cells give rise to different types of cortical neurons in a
specific sequence: 2 parts |
|
Definition
1. Subplate neurons (disappear later)
2. Neurons of cortical layer VI, V, IV, III, II (in this order) |
|
|
Term
| how is the cortex assembled? |
|
Definition
|
|
Term
|
Definition
|
|
Term
Neuroblasts migrate along
processes of... |
|
Definition
|
|
Term
The first neuroblasts
form the... |
|
Definition
|
|
Term
the next wave of
neuroblasts migrates
past the subplate and
forms the... |
|
Definition
|
|
Term
Once neuroblasts have reached their designated positions within
cortex, the cell... |
|
Definition
|
|
Term
|
Definition
“There is no adult
neurogenesis” |
|
|
Term
where can new neurons be generated in the
adult brain |
|
Definition
In the hippocampus
(Kempermann and Gage) and in the
olfactory bulb |
|
|
Term
More such neurons are
generated when the animals
are raised in... |
|
Definition
an “enriched” and
“interesting” environment. |
|
|
Term
| Three phases of the development of long-range connection pathways: |
|
Definition
(1) pathway selection
(2) target selection
(3) address selection |
|
|
Term
| The tip of a growing neurite is called the |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| chemoattractants, chemorepellents |
|
|
Term
Once a growth cone comes into contact with its
designated target... |
|
Definition
|
|
Term
|
Definition
refinement involves a dramatic reduction of neurons
and synapses |
|
|
Term
Neurons projecting to a target region
compete for a limited supply of
trophic factors, resulting in.. |
|
Definition
|
|
Term
During adolescence, in primate visual cortex, synapses are lost at a
rate of |
|
Definition
|
|
Term
| Synaptic rearrangement involves a.. |
|
Definition
change in the pattern of innervation
of a target neuron or region |
|
|
Term
| Synaptic rearrangement occurs as a consequence of neural activity and synaptic transmission which makes it... |
|
Definition
|
|
Term
Segregation of retinal axons
in the LGN:
Driven by... |
|
Definition
spontaneous
activity of retinal ganglion
cells in utero – no light input |
|
|
Term
|
Definition
ensures segregation in the
LGN. |
|
|
Term
| Initially, LGN inputs are __________ in layer IV of cortex |
|
Definition
|
|
Term
| Later, LGN inputs segregate into... |
|
Definition
|
|
Term
| monocular deprivation results in |
|
Definition
altered
patterns of columns |
|
|
Term
Segregation of ocular dominance
columns in striate cortex is what kind of process? |
|
Definition
| experience-dependent process |
|
|
Term
|
Definition
| (receive input only from one eye) |
|
|
Term
| Cells in cortical layer IV are... |
|
Definition
|
|
Term
After monocular deprivation there
is an... |
|
Definition
|
|
Term
|
Definition
|
|
Term
| why do you get cross eyed? |
|
Definition
almost complete loss of binocular neurons in
layer III |
|
|
Term
|
Definition
“what fires
together wires together" |
|
|
Term
Neuron A is highly active, but neuron B is only slightly activated →
synapse from A to B is weakened... |
|
Definition
“what fires out of sync loses
their link” |
|
|
Term
| The NMDA receptor has two “special” properties: |
|
Definition
(a) at resting potential,
Mg
2+
blocks the channel pore; (b) if the postsynaptic cell is depolarized,
the Mg2+ block is removed and calcium can enter the cell. |
|
|
Term
| Hebbian “coincidence detector” |
|
Definition
– if the detector is triggered/opened
synaptic plasticity should result. |
|
|
Term
|
Definition
|
|
Term
| The long-lasting increase in synaptic strength may be due to the |
|
Definition
| insertion of additional AMPA receptors. |
|
|
Term
Another form of cortical synaptic plasticity involves the weakening of
synapses (e.g. after weak correlations), called |
|
Definition
long-term depression
(LTD) |
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|
