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Neuro I > Memory > Flashcards

Flashcards in Memory Deck (72):
1

learning

acquisition of new information (facts)

2

Memory

retention of new information

3

learning and memory enable us to modify our behavior based on

new information and to extrapolate to unfamiliar situations

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Procedural memory

implicit memory
non-declarative
reflexive memory

skills and habits that have been used so much they are automatic

5

procedural memory - anatomic substrates

cerebellum - motor skills
nucleus accumbens - non motor

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Declarative memroy

explicit memory
the conscious recognition/ recollection of learned facts and experiences
subdivided into two forms

7

two forms of declarative memory

episodic - memory of events
semantic - memory of words, language, and rules

8

Declarative and procedural memory are coded for using

distinct anatomical stubstrates -

(the physiology is not very different)

9

Can also classify memory based on duration

short term
long term
working

the neural mechanism for each of these is DIFFERENT

10

short term memory

sec -hrs

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Long term memory

years

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WOrking memory

recalling a fact/memory for use - it may be a subset of short term memory

13

Working memory, ie

recalling a fact for use in a test question
you've learned it, now are retrieving it for use
will look very much like short term memory

14

declarative memory ie

the fact you learned for the test
this is events or facts stored in your memory

15

procedural memory i.e.

bike riding
motor skills that are used so much that you memorize the motor sequence required to produce the action

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short term memory i.e.

the fact that you crammed in 5 minutes before the test began

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long term memory i.e.

the memories of your life so far
involve changes in synapses, new synapses, etc

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The production of memory and learning requires the induction of

neuronal and synaptic plasticity

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Plasticity

alterations in the CNS based on use
may be synaptic function that;s altered
may be changes in the physical structure of the neurons (more synapses, new branches to new cells)

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Plasticity - 2 categories

changes in synaptic function
Changes in the structure of neurons

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plasticity - changes in synaptic functioning (3)

post - tetanic potentiation
pre-synaptic facilitation
Long term potentiation (LTP)

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plasticity - changes in the structure of the neurons (3)

Gain/loss of synapses
structural changes in dendrites
structural changes in the soma of the neuron

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Post tetanic stimulation - conditions

breif, high frequency discharge of presynaptic neuron
produces increased NT release
lasts about 60 seconds

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Post tetanic stimulation - Mechanism

the high level of stimulation allowed more Ca to enter the terminal than could be death with (faster than the Ca exchange pump can pump the Ca out)

With more Ca, mor vesicles fuse, leading to greater NT release

25

post tetanic stimulation duration

SHORT lasting, only lasts as long as it take the pump to get the CA out.
but sets the stage for other things.

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post tetanic stimulation duration

SHORT lasting, only lasts as long as it take the pump to get the CA out.
but sets the stage for other things.

27

Pre synaptic facilitation

start with a "normal" chemical synapse-->add another neuron that synapses on the presynaptic terminal of neuron A-->when activated, this terminal releases Serotonin,--> binding of the 5HT leads to activation of adenylyl cyclase and increased cAMP--> K channels in Neuron A become phophoyrlated and opening is delayed = depolarization is delayed

because the AP sticks around longer, we see greater NT release

28

LTP - definition

a series of changed in the pre and post synaptic neurons of a synapse which leads to increased response to the released NT

must last for HOURS after the stimulation
usually follows strong stimulation
NT can be EAA

29

LTP - definition

a series of changed in the pre and post synaptic neurons of a synapse which leads to increased response to the released NT

must last for HOURS after the stimulation
usually follows strong stimulation
NT can be EAA

30

LTP - mechanism (getting Ca into cell)

Eaa binds AMPA receptor, Na enters cell
depolarization--> displacement of Mg in NMDA channel
EAA binds NMDA and Ca can flow into cell

Ca is curcial to the development of LTP

31

LTP - how we get increased Na influx in response to EAA

Ca binds to calmodulin--> increased AC/cAMP--> phosphorylation of AMPA receptor= leave AMPA open longer to allow more Na into the POSTsynaptic cell (increase likelihood of AP from that cell)

32

LTP - Ca and presynaptic cell modifications

Ca binds to calcineurin--> activation of NOS--> production of NO--> acts on the PREsynaptic cell to increase cGMP and increase NT release

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LTP - CREB

LTP is also associated with gene transcription related to increased CREB.
with crab we can create the proteins that are going to help us with LTP

34

learning and the formation of new memories can be blocked by blocking ______
this tells us that ____

protein synthesis
protein synthesis is crucial

35

protein synthesis involves the

pre and post synaptic cells

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Gene transcription related to increased CREB in What cells? What do the proteins produced include

pre and post synaptic cells
NT synthetic enzymes
NT receptors
proteins required for growth/synapse formation

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post tetanic potentiation

increased activity increases amount of Ca in pre synaptic terminal increasing NT release

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presynaptic facilitation

serotonin release/binding to receptors on presynaptic terminal increases NT release by keeping neuron depolarized longer

39

LTP

changes in both pre and post synaptic responses to NT release so same NT release creates larger response (NMDA receptors)
lasts for hours

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CREB

changes in synapse structure (permanent)

41

Creating declarative (explicit) Memories - 4 parts

1. encoding
2. storage of the information
3. consolidation
4. retreival

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encoding

attending to new info
linking it to previous memories
higher cognitive funcitoning

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storage of the information

retention of information over time
long term capacity not limited

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consolidation

process of making a memory permanent
involves physical changes in synaptic structure

45

Retrieval

recalling or using the memory
bringing it into working memory
can be modified/lost at this point

46

Retrieval

recalling or using the memory
bringing it into working memory
can be modified/lost at this point

47

Short term memory - anatomical substrates (3)

hippocampus
parahipocampal cortex
prefrontal cortex

48

Short term memory - other interconnections

there are also interconnections to the neocortex and amygdala via the nucleus basal is of MEynert (cholinergic projection, a particular target of Alzheimer;s disease)

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Short term memory - physiological substrate

LTP

50

Short term memory - remember!

this is our TEMPORARY storehouse for memory
to move to long term, we need consolidation

51

Storage of the information - temporary storage

short term memory:
hippocampus
parahippocampal cortex
prefronal cortex
LTP in these areas allows us to store information

52

Consolidation - requires

HIPPOCAMPUS
temporal lobes
Papez circuit

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papez circuit

hypothalamus/mammillary bodies -->anterior thalamus--> cingulate cortex--> hippocampus--> REPEAT

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consolidating memory from short to long term

the "memory" is repeatedly sent through the Papez circuit, thus setting up the conditions required to induce LTP and neuronal plasticity (the repeated activation), back to the cortex, etc

Eventually the limbic system is not required for access to the memory

55

Long term memory- stored in the area of the cortex related to

the modality of the individual components (i.e. visual information is stored in visual cortex, etc)

56

Consolidation

requires continued activation of circuit
ANATOMY - papez circuit, temporal lobes, hippocampus
PHYSIOLOGY - LTP as starting point, continued activation (papez circuit), creates new synapses in required regions of the brain (visual, auditory, etc)

57

Long term memory "reassembling" - requires

neocortex
parahippocampal regions
hippocampus

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Recalling/retreiving memories - information related to each component of the memory is sent to the

parahippocampal regions

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from the parahippocampla cortex, the components are sent to

the hippocampus, where the entire memory is "reconstructed"

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after the hippocampus "reconstructs" the entire memory, information travels through the ______ to the _____

parahippocampus
cortex

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the parahippocampus is important in prolonging he life of the

cortical "trace" of the memory

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the parahippocampus is important in prolonging he life of the

cortical "trace" of the memory

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retreival

must take the memory components (visual etc) from "storage area"
back to parahippocampal cotex
to hippocampus (reconstructs the memory)
to cortex via parahippocampal region (keeps the trace)

64

Working memory - using retrieved memories
Three component model

central executive
phonological loop
visuospatial loop

65

Three component model - functions

central executive - what actually decides the facts you need to start saying "i was sitting here, looking at…"

phonological loop - the words associated with the memory

visuospatial loop - the physical circumstances

66

Three component model - anatomy

central executive - prefronal cortex
phonological loop - Broca's and Wernicke's
visuospatial loop - occipital cortex associated with vision

67

Spatial memory - a special case

unlike other long-term memories, a detailed memory of space is stored in the HIPPOCAMPUS, using special pyramidal cells in CA1 known as place cells
it appears that this spatial map serves as an anchor for the reconstruction of memory

68

spatial memory uses special ____ cells in _____ known as _____ cells

pyramidal cells
in CA1
place cells

69

detailed memory of space is stored in

the hippocampus

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______ serves as the anchor for the reconstruction of memory

spatial map created by place cells

71

Working memory

Central executive (prefrontal cortex) - directs/uses

phonological loop (broca and wernicke) - provide/interpret the auditory information associated with memory

visuospatial loop (occipital cortex, others) - provide/interpret the visual information associated with the memory

72

Spatial memory

special map in hippocampus codes for the physical space of the memory
place neurons in CA1 respond to specific locations within the space (a window, a door, etc)
this map is believed to anchor the entire memory