Neurophysiology of Learning and Memory

Question 1

What is procedural memory?

Answer 1

Motor skills that are learned and are automatic

Also implicit memory

Question 2

What structures are required for procedural memory?

Answer 2

Cerebellum for the motor part

Nucleus accumbens for non motor

Question 3

What is declarative memory?

Answer 3

Learned facts (episodic are events and semantic are memory of rules related to language)
Explicit memory

Question 4

What structure is required for declarative memory?

Answer 4

cortex

Question 5

Short, long and working memories. How are these processed?

Answer 5

• seconds to hours
• years
• recalling a memory for use

Processing each type have different physiology!

Question 6

What is required to actually make memory?

Answer 6

Physically changing the neuron itself or the synapses it makes (neuronal or synaptic plasticity)

Question 7

What is post-tetanic stimulation?

Answer 7

Synaptic plasticity mechanism
High frequency release of NT from pre-synaptic neuron > more bouts of Ca2+ entering the cell > greater NT release which increases the chance of AP in post synaptic cells

Question 8

What is long term potentation?

Answer 8

EAA stimulates pre and post synaptic neurons to change > results in increase response to the NT released at the synapse

Question 9

Using the EAA model, describe LTP

Answer 9

EAA binds non-nmda and nmda (with Mg+) receptors > Non-NMDA able to let Na+ in > depolarization > kicks Mg+ out of the NMDA receptor so calcium can enter its channel

Question 10

What overall effect does calcium have after entering the cell?

Answer 10

Increase post synaptic response and NT release

Question 11

Describe how Ca2+ alters post synaptic response via calmodulin

Answer 11

CA2+ binds calmodulin > increase cAMP > phosphorylation of AMPA receptors > increased Na+ influx > more depolarization > increased post synaptic response

Question 12

Describe how CA2+ alters post synaptic response via calcineurin:

Answer 12

Ca2+ binds calcineurin > activate NOS > create NO > diffuses across cells and increases cGMP and NT release

Question 13

What is CREB?

Answer 13

cAMP response element binding protein. Activated and induces gene transcription changes in pre and post-synaptic cell (neuronal plasticity) that produce proteins for new synapse (makes more NT, receptors, post synaptic density etc)

Question 14

What happens to learning and memory if protein synthesis is blocked?

Answer 14

Block learning and formation of new memories

Question 15

What are the 4 steps required to make explicit memories?

Answer 15

Encoding
Storage
Consolidation
Retrieval

Question 16

What is encoding and what can enhance it?

Answer 16

Focusing on the new info.

We can link it to previous memories or relate it with emotion

Question 17

The main player in information storage are

Answer 17

Short term memory (hippocampus, parahippocampal cortex, prefrontal cortex)

Question 18

How does the short term memory system work?

Answer 18

Projections from the main structures > Meynart > release Ach > neocortex and amygdala. (cholinergic) > excites the system to threshold leading to new memory formation

Question 19

Explain the relationship of Alzheimer’s disease to short term memory

Answer 19

Alzheimer’s targets the cholinergic system to Neocortex and amygdala. Results in difficulty making short term memories

Question 20

How do you physiologically store a memory in Short term memory?

Answer 20

Strengthening the synapses between the neurons in the hippo, parahippo and prefrontal (long term potentiation) allows info storage in short term memory (fire together)

Question 21

What is consolidation?

Answer 21

Making a memory permanent

Involves physically changing the synaptic structure of neurons that have LTPd with each other

Question 22

What anatomical structures are required to consolidate memory from short to long term?

Answer 22

Hippocampus
Temporal lobe
Papez circuit

Question 23

What is the Papez circuit pathway?

Answer 23

Hypothalamus/mammillary bodies > anterior thalamus > cingulate cortex > hippocampus (activation of relevant memories happens over and over)

Question 24

How does the Papez circuit work?

Answer 24

Continuous activation of the neurons in these areas related to the memory (neurons that fire together synapse together)
Papez in limbic system is required to encode, but not to retrieve

Question 25

After the papez encodes the memory, what happens to it?

Answer 25

Different features of the memory go to various areas of the cortex (sounds go to auditory, visual goes to visual cortex etc. This is done by creating new synapses in these areas.

Question 26

What is retrieval?

Answer 26

Recalling a memory and brining it to working memory. You need to reassemble the memory to retrieve it.

Question 27

What structures are required for retrieval to happen?

Answer 27

Neocortex
Parahippocampal gyrus
Hippocampus

Question 28

Describe the retrieval pathway

Answer 28

Neocortex (various parts that you disassembled the memory to) > parahippocampal gyrus > hippocampus (puts all the info together) > parahippocampus (prolongs the memory) > cortex for use (spit out on an exam)

Question 29

What model describes the working memory?

Answer 29

3 component model (central executive receives info from phonological loop and visuospatial loop and decides what you need at that moment (working memory))

Question 30

What serves as the components of the three component model of working memory?

Answer 30

Central executive - prefrontal cortex
Phonological loop - Broca’s and Wernicke’s
Visuospatial loop - Occipital cortex (with all the visual stuff)

Question 31

What is spatial memory?

Answer 31

Memory of the space we are in

Question 32

What is the major player in storing spatial memory?

Answer 32

Place cells in CA1 of hippocampus. These are special pyramidal cells.

Question 33

What are the features of place cells?

Answer 33

Place cells respond to geographic space, features of things and are more active when there is a reward

Question 34

How do place cells get their info?

Answer 34

Grid cells
Head direction cells (head rotations)
Border neurons
*all feed input to the place cells that tell it about the space you are in

Question 35

What are grid cells? How doe they help with retrieval?

Answer 35

Creates grid of the space in entorhinal cortex
Used as anchor/scaffold of a memory during retrieval (when I learned this I was in this room sitting on a wooden table etc.)

Question 36

What are border neurons?

Answer 36

Fire when close to borders in the space (there’s a wall there stop walking)