Final: Chapter 9 Flashcards by jnauman@tulane.edu Nauman

What are the 3 methods of refinement?

1) Refinment topography
2) refine convergence
3) refine postsynaptic compartment

How well did you know this?

Not at all

Perfectly

Refine Topography

correct location, but too far

How well did you know this?

Not at all

Perfectly

Refine convergence

remove connections

How well did you know this?

Not at all

Perfectly

Refine postsynaptic compartment

innervates soma and dendrites, then backs off dendrites

How well did you know this?

Not at all

Perfectly

Decrease in convergence means you eliminate…

input

in young neurons, increase based on how many neurons coming in, adult neuron has calmed it down, just takes 1

How well did you know this?

Not at all

Perfectly

Experiment: hippocampus crossing corpus C.

cells don’t die, but they will eliminate connections after crossing

How well did you know this?

Not at all

Perfectly

How do we image the cat brain?

3H proline
Retina: label aa, inject into cell, vesicle release chain to thalamus to cortex

white in photos: becomes organized swirl

How well did you know this?

Not at all

Perfectly

Experiment: cover primate eye

uneven left and right eye territory

need to use eye to keep competition

How well did you know this?

Not at all

Perfectly

Experiment: labeling with horseradish (HRP): what are the two steps in reducing retina ganglion cell terminates in LGN?

1) PRENATAL loss of branches in wrong layer

2) POSTNATAL: loss of extra branches

How well did you know this?

Not at all

Perfectly

Why does refinement occur at NMJ?

can’t extend and flex at same time, not just about who has more, but who has the right connections.

Usage shows what is wrong with the system

How well did you know this?

Not at all

Perfectly

Experiment: cat shut 1 eye at birth

monocular: one eye super long column

Thalamus doesn’t change, it’s the cortex that changes

How well did you know this?

Not at all

Perfectly

Experiment: cat shut both eyes

similar to controls, most cell binocular

How well did you know this?

Not at all

Perfectly

Experiment: shut 1 eye in adult

nothing happens, critical window, once window closed not plastic

How well did you know this?

Not at all

Perfectly

Monkeys: ocular dominance:

anatomical decrease faster than physiology,

The Layer 4 morphology changes before the physiological response

How well did you know this?

Not at all

Perfectly

What actually regulates critical period?

When GABA is inhibitory, critical window closes

How well did you know this?

Not at all

Perfectly

Pirate mice

1) normal adult
2) pirate baby mouse
3) pirate adult
4) GAD 65 -/- adults
5) MGE cells (P10) transplant in adult

1/3- adults normal

2/5/6- shifted

GAD-/- = no inhibitory GABA
MGE cells= no inhibitory GABA

How well did you know this?

Not at all

Perfectly

_______ leads to specificity of synaptic connections.

Synapse elimination

How well did you know this?

Not at all

Perfectly

Axonal withdrawal = (more/fewer) postsynaptic cells innervated

fewer

How well did you know this?

Not at all

Perfectly

Experiment: Strabismus Cat

not just the amount of activity, its the timing
can’t integrate L/R info.
NO SYNCHRONY

lose binocular connections
Graph look like two monocular bumps

How well did you know this?

Not at all

Perfectly

How does strabismus cat alter cortical projection pattern?

loss of horizontal projections in layers 1-3, look like weird stripes now

How well did you know this?

Not at all

Perfectly

Experiment: force frog to share tectum

not coactive, destabilizes so each eye gets own territory in tectum

based on surrounding activity

How well did you know this?

Not at all

Perfectly

For you give NMJ TTX cuff and eliminate AP,

Study These Flashcards

polyneuronal innervation remains

Experiment: NMJ, increase stimulation

Stimulate wrong contact

Study These Flashcards

speed up process, lose MN connections

Stimulate wrong contact = wrong connection

Motor neuron elimination and distance

Study These Flashcards

only competition is near by, if far enough apart, you can stimulate one and still not get elimination of the other

Stimulus orientation of lines is noted by different recordings from

primary visual cortex

Experiment: cat with line glasses

Better at vertical stuff than controls

Experiment: strobe light cat, only see stationary objects

worse than controls at detecting motion

Ferrets: reared in the dark

orientation diminished motion direction detection is gone through Different aspects of vision have different windows

Experiment: Frog eye rotate 180 degrees

location of stimulus moves, temporal of other eye synapse at new location

Experiment: Rats in clicking environment

no refinement respond to broad range of frequencies and broader frequency tuning properties Ruined topographical organization in cochlea

Remapping Owls: 23 degree prism glasses: Thinks mouse in front. 60 microsecond difference between ears hearing squeaks inject tracer to ICC optic tectum- where visual/auditory integrate

result: auditory map adjusts to the visual map. normal experience essential for good synaptic refinement

Activity dependent development includes activations of

NMDA R and CAMK2

Heterosynaptic depression = (increase/decrease) in synaptic strength

decrease

_____ mediates alterations in synaptic strength

2nd Messengers

Spontaneous visual activity Experiment: 1) Dark reared cat 2) TTX block cat

pattern until eyes open - helps ocular dominance Spontaneous retinal activity = stripe formation in layer 4 TTX block = no stripe

Spontaneous activity: auditory Experiment: isolate cochlea, use ATP antagonist

Normally, supporting cells release ATP, acts like NT, cells release glutamate Eliminates spontaneous activity

Spontaneous activity: Cortex

Ca2+ signal caudal --> rostral Ends when inhibitory synapse become hyperpolarizing

Heterosynaptic depression at NM synapse LP vs. SN Stim SN = muscle contraction, but Stim LP...

activity in one synapse depresses another SN gives weaker muscle contraction. LP doesn't change, but decreases the other

How does heterosynaptic depression work:

Stimulation: PKA and PKC PKA: activated by ligand release with AcH, protects AChRs under active terminal PKC: activated by Ca2+ influx, phosphorylates AChRs on inactive terminal

ProBDNF and synaptic withdrawal

retrograde signal. proBDNF= synaptic depression, withdrawal from presynaptic target. Block with p75NTR - synaptic depression and withdrawal

Experiment: UV light increases Calcium influx 1) UV + muscle, Ca2+ increase 2) Same, but add that presynaptic activity

1) synaptic depression | 2) add presynaptic activity, no retrograde signal to depress

To activate, NMDA-R needs

1) depolarization to get Mg2+ block out | 2) Glutamate

Experiment: 3 eyed frog 1) Control 2) NMDA block (APV/MK801) 3) NMDA receptor activation

1) lines 2) no lines 3) VERY distinct lines increase NMDA = retinal terminal segregation

Dendrite synapse formation and CAMs Activity = (more/less) CAMK2 due to ___

more CAMK2 due to Ca2+

CAMK2 phosphorylates ____ and ____ which results in...

DLG (synaptic protein) Fas2 (cell adhesion molecule) less adhesion, more sprouting. Fas 2 not synaptic

Flies with increase cAMP have

decrease Fas2, more bountinal ends

LTD in development; what happens to it

Decreases as you develop. At first, low freq. stim has long lasting depression, then no effect

Depressed synapse

decrease colocalization of pre/postsynaptic elements

increased stability

equally likely to colocalize region

GABA transmission is need for normal inhibitory synapse formation, what happens in GAD67-/-

no GABA synthesis lose inhibitory synapses because they aren't functional, and don't activate

synaptic activity/dendrite length: dendrite morphology depends on ___ contact

presynaptic

Postsynaptic targets are branchier when

more activity, used more

Experiment: cut NM affert axons at the midline Golgi stain results?

Ventral dendrites shorter than those on dorsal side

Normally, dendritic spine mobility decreased, but in binocular deprived,

spine mobility increased, doesn't like not activity at all, can't lose everything, trying to bring it back

Final: Chapter 9 Flashcards

(54 cards)