Learning And Memory Flashcards
What is learning?
Acquisition of new info
What is memory?
Retention of new info
What are the types of memory?
Procedural (implicit, non-declarative, reflexive)
Declarative (explicit)
Working (recall)
How is memory classified in terms of time?
Short term
Long term
What is procedural memory for?
Example?
‣ Skills and habits used so much they are automatic, motor sequences is memorized
‣ I.e bike riding
What are the anatomical substrates involved with procedural memory?
Function of each?
- Cerebellum: motor skills
* Nucleus Accumbens: non-motor
What is declarative memory for?
Example?
‣ Conscious recognition/recollection of learned facts and experiences
I.e. the fact you learned for test; events/facts stored in memory
What is declarative memory subdivided into?
Episodic
Semantic
What is episodic memory?
Memory of events
What is semantic memory?
Memory of words, language, and rules
How long does short term memory last?
Seconds to hours
What is working memory?
Example?
Recall a fact/memory for use
‣ I.e. recall a fact for use in test question (very much like short term- actually a subset)
What does the production of memory and learning require?
Induction of neuronal and synaptic plasticity
What is plasticity?
Mechanism?
Alterations in CNS based on use
Change to Synaptic function
Change to Physical structure of neuron
What changes to synaptic function could be made for plasticity?
Post-tetanic potentiation
Long term potentiation (LTP)
What changes to the physical structure of neurons could occur as a result of plasticity?
- Gain/loss synapses
* Structure changes in dendrites
* Sturcutral changes in soma of neuron
What is post-titanic potentiation?
What is its effects?
High level of stimulation that allows more ca to enter terminal than could be dealt with
More vesicle to fuse
Greater NTR release
Greater probability of AP in Post syn cell
What can stimulate Post-tetanic potentiation?
Brief high frequency discharge of pre synaptic neuron
= increased NTR for ~60 sec
= increased probability of AP in post syn.
What is long term potentiation?
Series of changes in pre- and post synaptic neurons of a synpase which leads to
increased response at NMDA receptors to released NTR that can last for hours
What changes are associated with Increased CREB’s gene transcription?
Long term potentiation
Neuronal plasticity
What does increased CREB do in terms of neuronal plasticity?
Changes synapse structure permanently
&
creates new synapses via protein synthesis
What proteins does CREB produce for neuronal plasticity changes?
NT synthetic enzymes
NT receptors
Proteins for growth/synapse formation
What could blocking protein synthesis lead to in term of learning and memory?
Bc neuronal plasticity relies on protein synthesis
Blocking it can block learning and formation of new memories
What is the basic pathway for creating Declarative memories?
Encoding —> storage —> consolidation —> retrieval —> recall ar WOrking memory
What is the process of encoding?
Attending to new info (focus, attention) and linking it to previous memories and emotions
What is storage in the process of creating declarative memories?
Retainment of info over time using short and long term
What are the anatomical substrates used for storage in short term memory?
Hippocampus
Parahippocampal cortex
Prefrontal cortex
Nucleus of basalis of Meynert
Amygdala
Neocortex
What does the Nucleus Basalis of Meynert do in terms of storage in short term memory?
Provides the interconnection to the neocortex and amygdala via ACh projections
What is a target of Alzheimer’s disease?
Nucleus Basalis of Meynert
In order to store info, what plasticity change do we need to occur?
Long term potentiation
What is consolidation?
Process of making memory permanent
Aka moving it from short term to long term memory
What are the anatomical substrates required for Consolidation?
Hippocampus
Temporal lobes
Papez circuit
What is the papez circuit?
Cingulate cortex —> hippocampus —> hypothalamus/mammillary bodies —> anterior thalamus —> cingulate cortex
What is the process for consolidation?
Memory is repeatedly send thru the Papez circuit, inducing long term potentiation and neuronal plasticity
Where are long term memories stored?
In area of cortex related to MODALITY of the individual components
i.e. visual info of a memory stored in visual cortex
What is Retrieval in the process of creating declarative memories?
Recall or use memory
Bringing fragment into Working memory
When are memories modified or lost?
During retrieval (when you try and bring it into working memory)
What anatomical substrates are required for recall/retrieval of memories?
Neocortex
Parahippocampal regions
Hippocampus
What is the process of Recalling memories/
Memroy components from “storage area” back to parahippocampal regions
—> hippocampus, memory reconstructed here
—> thru parahippocampus (to keep trace)
—> cortex
—> working memory
Where is an entire memory reconstructed?
In hippocampus
What is the importance of the Parahippocampus?
Important in prolonging life of cortical trace of memory
What uses the retrieved memories?
Working memory
What is the 3 component model used by Working Memory?
Central executive
Phonological loop
Visuospatial loop
What is the function of the central executive of working memory?
Anatomical substrates?
Directs/uses memory
Prefrontal cortex
What is the function of the phonological loop of working memory?
Anatomical substrates?
Provides/interprets auditory info associated w/ memory
Broca’s and Wernicke’s area
What is the function of the Visuospatial loop of working memory?
Anatomical substrates?
Provides/interprets visual info associated with memory
Occipital cortex (+others)
What is spatial memory?
Detailed memory of space that serves as scaffold for RECONSTRUCTION of entire memory (hippocampus)
Where is spatial memory stored?
Using what?
In hippocampus using special pyramidal cells in CA1 called “Place Cells”
What are Place Cells?
◦ Neurons that are active only at specific places and especially active if you got a reward at that place
Final mediator of spatial memory
When do place cells fire?
‣ Fire when in specific place or recalling a specific place
Especially active if you received a reward at that place
What do Place Cells receive inputs fro?
Grid cells
Head direction cells
Border neurons
Etc.
What is the function of head direction cells?
Give input to place cells about which direction your head was pointing to, to see/explore area
When will border neurons fire and send info to Place Cells?
• Fire when near a border (wall, etc..)
What is the function of Grid Cells?
◦ Creates a mpa of place you are in
‣ Grid map
‣ Triangular or hexagonal grid
Sends input to Place Cells
Where are Grid Cells located?
In entorhinal cortex of hippocampus
When are Grid Cells active?
When exploring an area
have to be in area for them to be active
What is an important component of encoding/
Emotion
What is the physiology for consolidation?
LTP as starting pt.,
continued activation (Papez circuit),
creation of new synapses in assoc. regions of brain (visual, auditory, etc.)
What is the signal transduction pathways for Long Term potentiation?
EAA —> non NMDA, Na enters, DEPOLARIZATION
Mg released from NMDA r.
EAA—> NMDA, Ca and Na enters
Ca —> Calmodulin —>Incr. Adenylyl cyclase/cAMP —> AMPA r. Phosphorylation —> allows for INCREASE in Na Influx in response to EAA ==> bigger post synaptic response
Ca —> Calcineurin —> Activates NOS —> NO to diffuse back to presynaptic cell —> increase cGMP —> Increase NTR release
