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Zoology 242 > Learning and Memory > Flashcards

Flashcards in Learning and Memory Deck (46)
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1
Q

Describe sensory memory

A
  • large capacity, but rapid decay
  • sensory association areas involved
2
Q

Describe short-term (working) memory

A
  • lasts for seconds to minutes
  • severely limited capacity
  • available to conscious awareness
  • prefrontal cortex involved
3
Q

Describe intermediate-term memory

A
  • lasts for hours and days
  • may be transferred to LTM through rehearsal
4
Q

What are the two types of long term memory?

A

Explicit (declarative) and implicit (non-declarative)

5
Q

Describe declarative memory

A
  • involves hippocampus and medial temporal lobes
  • neurons in hippocampus register info about the space surrounding an animal
    • cognitive map of the external environment
6
Q

What is synpatic plasticity?

A

​Change in synaptic function in response to patterns of use

7
Q

What is synaptic facilitization/sensitization?

A

Repeated APs result in increased Ca n terminal, increased NT release

8
Q

What is synaptic depression/habituation?

A

Repeated APs deplete NT in terminal, decreased NT release

9
Q

What was Eric Kandel’s model of choice?

A

Aplusia californica (Sea Hare)

10
Q

Why did Kandel pick aplysia?

A
  • small number of neurons
  • large neurons
  • culturable neurons that form circuits in vitro
  • responses are visible and measurable
  • respone triggered by several electrical synapses firing simultaneously
11
Q

What was the main reflex Kandel studied?

A

Gill withrawal reflex

12
Q

Describe the difference between habituation and sensitization.

A
  • Habituation
    • repeated stimulus leads to “ignore”
    • “negative” memory - not stored
  • Sensitization
    • stimulus results in response
    • results in consolidated memory
13
Q

What is the simplest formation of implicit learning?

A

Habituation

14
Q

Describe habituation in terms of neurons (aplysia?)

A
  • size of EPSP by sensory neuon on motor neuron decreases in amplitude
  • inactivation of calcium channels
  • less Ca2+entering nerve terminal of presynaptic membrane
    • less NT released
15
Q

Describe sensitization in terms of neurons.

A
  • large increase in amplitude of EPSP
  • increase in amount of NT released
  • amplification due to interneurons
16
Q

Describe signalling by the interneurons (short term sensitization)

A
  • excitatory interneurons release serotonin (5-HT)
  • 2 serotonin receptors in Aplysia
    • 5-HT2 like receptor
      • PLC pathway
    • 5-HT4,6,7 like receptor
      • adenylate cyclase pathway
17
Q

Storage of long-term memory results in ___________ in the presynaptic termini.

A

Physical changes.

  • Habituation
    • retraction of presynaptic termini
    • in aplysia, 35 fewer connections with motor neurons and interneurons
  • Sensitization
    • increase in number of connections
    • in aplysia, 2 fold increase
18
Q

What were the long term changes in habituation and sensitization in the aplysia?

A
  • normal aplysia showed 1300 axon terminals on sensory neurons
  • aplysia experiencing sensitization had 2800 terminals
  • aplysia experiencing habituation had 800 terminals
19
Q

Describe long term sensitization.

A
  • cAMP binds to and activates CREB
    • cAMP response element binding protein
  • MAPK may also be involved
  • CREB translocates to nuclues and increases gene expression of specific gene
  • changes protein profile of synapse - changes in size etc.
20
Q

What is the feedback loop involved in long term sensitization?

A
  • one gene synthesized in response to CREB is ubiquitin hydroxylase
    • degreade regulatory domain of PKA
    • results in continuous activity of PKA
    • Ks is continuously phosphorylated
    • AP prolonged
    • Ca influx almost permanent
    • continued release of NT
21
Q

What is BDNF?

A

Brain-derived neutrophic factor

  • ​activated by NMDA receptor
  • in aplusia, blocking BDNF - no long term memory
  • corticosteroids decrease BDNF
  • activates growth of dendritic spines
  • role in generation/localization of new receptors
22
Q

What test tested the spatial memory of vertebrates?

A

Morris water maze

23
Q

What NT/receptor are used in learning pathways for vertebrates?

A

Glutamate

24
Q

Does the learning pathway in vertebrates require an influx of Ca2+ into the post-synaptic cleft?

A

Yes

25
Q

What 3 protein kinases does Ca2+ activate in the learning pathway of vertebrates?

A
  1. Calcium/calmodulin kinase
  2. PKC
  3. Tryosine kinase fyn
26
Q

What is long-term potentiation? Where was it first measured?

A

Stumilation of pre-synaptic neuron leads to a long-term increase in the magnitude of EPSPs in post-synaptic neurons. First measure in hippocampal tissue.

27
Q

What effect does LTP have on synapses?

A

LTP strengthens existing synapses and also creates new ones.

28
Q

What is needed for LTP to occur?

A

Rapid rate/high frequency of stimulation.

29
Q

What are the two types of LTP glutamate receptors?

A

AMPA and NMDA

30
Q

Which LTP glutamate receptor is activated first?

A

AMPA; activated first, ionotropic, local depolarization events

31
Q

NMDA is normally blocked by _____. And requires what typed of even to open?

A

Mg2+, requires depolarization event and Glu binding to activate.

32
Q

AMPA receptor has ___ subunits and ___ agonist-binding sites.

A

4 and 4

33
Q

What does NMDA stand for?

A

N-methyl-D-aspartate

34
Q

What are the characteristics of NMDA?

A
  • heterotetramer
  • non-specific cation channel
  • blocked by Mg2+ at RMP
  • preferentually allows Ca2+ passage
35
Q

What are the other two types of glutamate receptors? (Other than AMPA and NMDA)

A

Kainate and mGluR

36
Q

Which of (non AMPA and NMDA) glutamate receptors is metabotropic?

A

mGluR

37
Q

___________, activated by Ca2+ influx, is a mediator of downstream effects.

A

Calmodulin-dependent kinase (Calmodulin is activated by Ca, which then activates kinase).

38
Q

What are the 2 main phases of LTP? Describe them.

A
  1. Establishment
  • induced experimentally by single high-frequency stimulus
  • invovles kinases but not protein synthesis
  1. Maintenance
  • experimentally requires a series of high-frequency stimuli
  • requires protein synthesis
39
Q

What happens during early LTP (establishment)?

A
40
Q

What happens in late LTP (maintenance)?

A
41
Q

How does LTP change the pre-synaptic termini?

A

Increased synaptotagmin and number of SVs

42
Q

What is synaptic tagging?

A

Protein tage present in active synapses. Direct localization of mRNA bundles.

43
Q

What is the reverse of LTP?

A

Long term depression

44
Q

What is LTD?

A
  • decrease in dendrites/spines
  • due to low frequency stimulation
  • may be necessary for eliminating memory traces
  • important in motor learning
45
Q

Is the NT for LTD still glutamate?

A

Yes

46
Q

LTD involves ______ and phosphorylation of _______.

A

MAPK and AMPA receptors