Learning and Memory Flashcards
Declarative and procedural memory
Declarative aka explicit memory can be episodic or semantic - events or actual words of a language
- processed by the cortex
Procedural aka implicit memory
-reflexive memory, skills that have been used many times
- cerebellum and nucleus accumbens are involved
Working memory
Recalling a fact or memory for use - may be a subset of short-term memory
Post-tetanic potentiation
Brief, high frequency discharge of presynaptic neuron
Increase in NT release for 60sec or so
Increase probability of AP in post synaptic cells
Long term potentiation
Pre and post synaptic neurons change
More neurotransmitter release and more response to NT
Long term potentiation affect on AMPA
More NT release causes more sodium influx into cell (via non-NMDA receptor)
Depolarization removes Mg from NMDA, increasing calcium influx resulting in calmodulin activation and cAMP activation, causing phosphorylation of AMPA receptor, which causes it to allow more sodium inside
Calcineurin is also activated which leads to NO production and NO diffuses back to pre synaptic cell and increases cGMP which increases NT release
Long term potentiation and gene transcription
LTP activates gene transcription resulting in more CREB production (cAMP response element binding protein)
CREB is the link between synaptic functioning changes and structural changes in neurons
Storage of the information (creating a declarative memory)
Retention of information over time
Short term memory is important here
-Hippocampus is heavily involved in short term
**There are interconnections to the neocortex and amygdala via the nucleus basalis of Meynert, a cholinergic projection
- this is a particular target of Alzheimers
- LTP is required for short term (unless it is a couple seconds of memory)
Consolidation (creating declarative memory)
Creating new synaptic connections
Requires- hippocampus, temporal lobes, papez circuit
Papez circuit
Hypothalamus/mamillary bodies--> Anterior thalamus--> Cingulate cortex--> Hippocampus--> Hypothalamus This circuit sets up the conditions required to produce LTP and eventually is not needed in order to access the memory
Long term memory
Requires:
Neocortex- different areas of cortex (visual etc..) send pieces of memory to parahippocampal regions Parahippocampal regions send to the hippocampus
Hippocampus is responsible for reconstruction entire memory
Memory then send back through parahippocampal regions and then cortex
Working memory - using retrieved memory- 3-component model
Central executive - figuring out what you need to remember (prefrontal cortex)
Phonological loop - what words were used to describe this memory (Brocas and Wernickes)
Visuospatial loop - what did this memory look like (occipital cortex)
Spatial memory
Detailed memory of space is stored in the hippocampus using special pyramidal “space” cells
This spatial map serves as an anchor for the reconstruction of memory
Even more beneficial if there is a reward associated
Inputs to space cells
Grid cells send inputs- create a map of a place you are in
Head direction cells
Border neurons
