Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

neural circuits > memory, LTP and LDP mechanisms > Flashcards

memory, LTP and LDP mechanisms Flashcards

1
Q

Learning

A

acquisition of information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Memory

A

storage of learned information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Recall

A

reacquisition of stored information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The engram

A

physical embodiment of a memory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Procedural memory

A

Skills and associations largely unavailable to conscious mind
e.g riding bike

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Declarative memory

A

Available to conscious mind. Can be encoded in symbols and language

e.g capital of france

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Explicit memory

A

memory that can be consciously recalled (e.g. recalling riding a shiny new bike on the Christmas day when you were 5)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Implicit memory

A

memory that cannot consciously recalled (e.g. learning to ride a bike). Can be different types:
- Procedural memory
- Classical conditioning
- Priming (when one stimulus influences the response to subsequent stimuli)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Priming

A

when one stimulus influences the response to subsequent stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

advantages of using lower vertebrates as models for simple systems

A
  • neuronal size
  • circuit complexity
  • temperature dependence
    • switches neurones on/off
  • mapping tools
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

simple forms of memory

A

habituation = desensitisation
sensitisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is habituation

A

desensitisation of response to stimuli
- amplitude of response reduces if stimulus is repeated
- of eye blink reflex
- of repetitive non-harmful stimulus presentation
- of visual attention
- of emotional response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is sensitisation

A

increases amplitude of response over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what do studies of aplysia gill withdrawal reflex show?

A
  • Touch or water jet causes gill withdrawal
    • contains sensory neurones
  • Habituation to repeated stimuli
  • 10-15 touches at 10-20 sec interval reduces the reflex
  • sensory neurone (siphon skin) → motor neurone (gill muscle)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

origins of habituation

A
  • pre-s neurone = regular amplitude of neurone firing
  • post-s neurone = declining amplitude of neurone firing

⇒ origin is somewhere between pre and post synaptic neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the mechanism of habituation (desensitisation)

A
  • caused by reduced transmitter release / depletion of readily releasable pool
  • less vesicles available in active zone to be released = less aplitude
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the readily releasable pool

A

what is released immediately when post-s depolarises (active zone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the reserve pool

A

spare vesicles and NTs that require high depolarisation to be released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

explain how desensitisation (habituation occurs)

A

when you stimulate specific neurones repeatedly, the amount of vesicles available to transmit neurotransmitters is depleted requiring higher stimulus to use reserves -> meaning there are weaker signals sent as a result

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does sensitisation occur

A

L29 sensitising neurone releases serotonin → activates adenylyl cyclase → cAMP → PKA → phosphorylation of ion channels including K channels -> longer depolarisation period = sensitised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

habituation and sensitisaiton summed up in a sentence

A

Habituation: depletion of the synaptic vesicle pool
Sensitisation: serotoninergic feedback from other sensory neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how does associative learning occur in a simple model

A

when L29 has an EPSP -> other sensory neurones around can be depolarised causing increased depolarisation of nearby neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what do the mechanisms of sensitisation and conditioning typically involve

A
  • Multiple intracellular signalling pathways
  • Pre and post-synaptic
  • Long term involves the nucleus
    • requires changes to gene expression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what enzymes are involved in early stages of associative learning

A
  • PK2
    • activated by Ca
  • PKa
    • activated by cAMP?
  • PKC
    • activated by diceglycerol
  • produced by G proteins/channels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what molecule activates PK2
Ca
26
what molecule activates PKA
cAMP
27
what molecule activates PKC
diglycerol
28
what enzymes are involved in late stages of associative learning
- MAP kinase - travels from cytoplasm → nucleus and phosphorylates TF → gene expression - proteins are transported to synapse - establishes longer response
29
what is the concept of hebbian synapse
Coordinated activity of a presynaptic terminal and a postsynaptic neuron strengthen the synaptic connections between them ie neurones that fire together wire together
30
major role of hippocampus
→ spatial memory formation
31
structure of hippocampus
- many layers - input from entorhinal cortex - dentate gyrus -> CA3 contains mossy fibres - CA3 -> CA1 contains schaffer colaterals - neuronal output via fornix and subiculum
32
what is cooperativity
Cooperativity refers to the need to stimulate multiple afferent fibers to induce LTP
33
what have experiments shown about LTP
- ca3-ca1 synapses are glutaminergic - high freq stim (1000Hz) produces long lasting potentiation → increased firing rate
34
types of glutamate receptors
AMPAR - opens = depolarises cell - Na+ mGluR - metabotropic NMDA - Ca2+ - v-dependent Mg2+ block - phosphorylation
35
how do NMDA glutamate channels work
- Ca2+ channel - activates kinases - phosphorylates proteins to increase EPSP - requires depolarisation to remove v-dependent magnesium block
36
how does early phase LTP work
- NMDAR mediated Ca activates calmodulin kinase II - autophosphorylation and activation triggered by Ca - phosphorylation enhances AMPA currents - increased potentiaion = increased currents
37
what is AMPAfication
- pre-s excitatory signals causes delivery of ready-prepared AMPA receptors to the synapse, increasing EPSP
38
how does late stage LTP work
- long term storage requires protein synthesis - cAMP → PKA → activates proteins and phos proteins in nucleus - CREB binds to CRE to stimulate phosphorylation of CREB transcription
39
impact of LTP on memory formation
inhibiting LTP inhibits some memory formation
40
which mutations/drugs can affect learning
Mutations of CaMKII, NMDARs, cAMP pathway all affect aspects of learning
41
inputs and outputs of cerebellum
+ve inputs = mossy and climbing fibres (efferent) -ve outputs = purkinje cells
42
synapses of climbing fibre
climbing fibre has multiple synapses on 1-10 purkinje cells1 climbing:1-10 purkinjes
43
synapses of mossy fibre
mossy fibres synapse onto 1 granule cell and contact 1000 purkinje neurones 1 mossy:1 granule(parallel):splits to contact 1000s purkinjes
44
do mossy or climbing fibres form stronger synapses?
climbing fibres, becuase its 1:1, not 1:1:1
45
what does activation of a climbing fibre do
depolarisation of purkinje cell
46
how to measure purkinje synapses
- recording purkinje cell response to parallel fibre = measure EPSP amplitude - stimulate parallel fibre simultaneously = changes in synapse and decrease in amplitude of EPSP
47
which glut channels are involved in cerebellar LTD
- metabotropic Glutamate receptors, AMPA-R and V-gated Ca2+ channels - not NMDA
48
types of synapses in cerebellar long term depression
climbing:purkinje = AMPA receptors granule/parallel:purkinje = metabotropic glutamate receptors - stimulate only parallel fibre = not much PKC activated - stimulate climbing + parallel = lots of AMPA activation → strong depolarisation of purkinje cell → V gated Ca2+ increased ic[Ca2+] → Ca2+ increases activity of PKC
49
difference between climbing and parallel fibres
Climbing fiber synapses contact spines on the primary Purkinje cell dendrite, whereas parallel fiber synapses contact spines on secondary and tertiary dendritic branches
50
how does long term depression occur in cerebellum?
1. climbing + parallel increases PKC activity due to Ca2+ 2. PKC phosphorylates AMPA GluR2 subunit 3. causes AMPA receptors to be endocytosed 4. reduced EPSP
51
how does long term depression occur in cerebellum?
1. climbing + parallel increases PKC activity due to Ca2+ 2. PKC phosphorylates AMPA GluR2 subunit 3. causes AMPA receptors to be endocytosed 4. reduced EPSP
52
can LTD can reverse an LTP?
yes via depotentiation
53
how does hippocampal long term depression occur
- synapses become weakened when they are active but the rest of the cell isn’t - LTD and LTP are Ca2+ dependent - degree of NMDS receptor activation determines probability of inducing LTP or LTD
54
where does hippocampal LTD occur
- occurs at CA3-CA1 neurones synapse
55
what enzymes are activated via LTP
kinases
56
what enzymes are activated via LTD
phosphatases
57
role of calcium in hippocampal LTD/LTP
- small increases in Ca from NMDA trigger more phosphatase action → reduces AMPAR efficacy - large increases in Ca from NMDA activate more protein kinases → increase AMPAR efficacy
58
what is adaptation
form of plasticity change of response to same stimulus
59
what fluorescent proteins show proton release following NT release
- sypHy - reporter of neural activity - fluorescent when H+ has been exocytosed
60
role of - iGluSnfr protein
- fluorescent reporter of glutamate - glutamate changes conformation of protein → bright

neural circuits (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions