Learning And Memory

Question 1

What lobectomy did HM have

Answer 1

Bilateral medial temporal lobectomy

Question 2

What were the symptoms of HM

Answer 2

No new long term memories
Still make procedural memories
Short term memory intact

Question 3

Parahippocampal cortex function

Answer 3

Site for convergence for cortical input. Outgoing info from hippocampus is sent back here

Question 4

Circuits of the hippocampus

Answer 4

EC-DG= performant path
DG-ca3= mossy fibres
Ca3-ca1=Schaffer collateral
Ca1-EC= perforant path

Question 5

What receptors are required for spatial memory formation

Answer 5

NMDAR

Question 6

Hebbs law

Answer 6

Neurons that fire together wire together

Question 7

What two proteins are needed for LTP

Answer 7

CamkII - early LTP
PMKZ - late LTP and maintenance

Question 8

What happens if LTP is continually inducted

Answer 8

LTP is saturated and it impairs memory (spatial memory evidenced to be worse)

Question 9

What happens if fEPSP slope is enhanced (ltp)

Answer 9

It can stop subsequent LTP as there is more potentiation during a task which prevents it from being potentiated further after the learning task

Question 10

What is an engram

Answer 10

Physical representation of memory in the brain

Question 11

Purpose of engram cells

Answer 11

Activated by a learning experience and reactivated by subsequent presentation of the stimulus for memory retrieval

Question 12

What are silent engrams

Answer 12

Engrams that have been damaged so the memory is unavailable and can’t be naturally retrieved but not lost completely

Question 13

What can be used to track neurons while learning

Answer 13

C-fos

Question 14

Egocentric

Answer 14

Location of self relative to object

Question 15

Allocentric

Answer 15

Location of object relative to object

Question 16

Role of prefrontal cortex in memory

Answer 16

Short term memory and executive function

Question 17

Parietal cortex in spatial navigation

Answer 17

Attention and planned movements

Question 18

Retrispinal cortex in spatial navigation

Answer 18

Episodic memory and cognition

Question 19

How can you identify place cells

Answer 19

Each place cell is only active in one spatial location
They each have distinct firing fields to each other
Stay active over time but will remap in new environments
Found in hippocampus

Question 20

What are components of hippocampal formation

Answer 20

Ec
Subiculum
Pre subiculum
Para subiculum
Hippocampus

Question 21

What are hippocampus ripples

Answer 21

Cells that fire in a socific order in an environment will replay after event e.g during sleep (high frequency events). They are important for synaptic plasticity and can preplay before the event

Question 22

What is phase procession

Answer 22

Individual spikes from a place cell will occur at different phases of the hippocampus waves. Spikes from B will always fire after A. Replay In same way during sleep

Question 23

How to identify grid cells

Answer 23

Found in EC
Have multiple firing fields that are spaced at a regular distance from each other
Form hexagonal patterns
Don’t remap in new environments

Question 24

How is scale achieved by grid cells

Answer 24

Cells in the dorsal medial EC have smaller firing fields and those in the ventral EC have a larger firing field which is spaced further apart

Question 25

What are border cells

Answer 25

Only fire at the edge of environments (near a border). Found in the EC but mostly subiculum. They remain when a new boundary is in place

Question 26

What are head direction cells

Answer 26

Only fire when facing a particular direction. Cover all angles available in environment.

Question 27

What is encoding velocity

Answer 27

Cells fire in relation to how fast the animal is moving. Modulated by speed cells found in the medial EC, basal forebrain and medial and lateral septum