Lecture 17 Review

Question 1

What’s the difference between short-term and long-term memory?

Answer 1

short term
- aka working memory
- close to sensory information, active information buffer
long term
- relatively permanent
- requires consolidation (long lasting change in neuron function)

Question 2

What are the types of amnesia?

Answer 2

retrograde = before the event 
anterograde = after the event 
global = both

Question 3

What’s the difference between declarative memory and non declarative memory?

Answer 3

• Declarative memory is something you can consciously report
• nondeclarative memory is something you learned about but do not remember the events that cause the plasticity in circuits to change for learning
  • i.e. classical conditioning, procedural memory, etc.

Question 4

How does synaptic modification play a role in learning?

Answer 4

• learning involves mostly with changing synaptic connectivity
• coincident neural connectivity is key in wiring the brain
  •neurons that fire together will wire together
  •out of sync will lose the link

Question 5

What role do glutamate receptors play in synapse plasticity

Answer 5

• AMPA, NMDA, and metabotropic glutamate receptors are key to plasticity
• they must be coincident with extracellular glutamate and internal depolarization

Question 6

Describe HM and how he was significant to learning and memmory

Answer 6

• epileptic man who was cured by removing the foci
• had declarative memory deficits
  •could not form new memories
  •short term memory intact but long term memory lost
  • specific disruption of consolidation
  •implicit memory was normal, procedural memory was normal

Question 7

Describe the role that the medial temporal lobe has in declarative memory

Answer 7

Critical for declarative memory

• delayed non-matching example monkey experiment. memory decreased over time
• hippocampus receive input from the entorhinal cortex, outputs through the fornix

Question 8

What structure is central for amnesia?

Answer 8

Peri-rhinal (PR) cortex

Question 9

What role does the hippocampus have in memory?

Answer 9

• very involved in remembering places, navigation, and specific places
• roles in emotional regulation
• navigation requires interaction with entorhinal cortex
• closest link is to relational memory - linkage between stimuli

Question 10

How is long term potentiation produced?

Answer 10

• Produced by high frequency stimulation of CA3 projections in CA1
• synapse must be active at the same time that a postsynaptic CA1 neuron is depolarized
• repeated coactivation of synapses = firing together makes them linkes = cooperativity

Question 11

How is long term depression produced?

Answer 11

Low frequency stimulation of CA3 projection in CA1

- produces weaker synapses

Question 12

How does AMPA and NMDA receptors affect LTP?

Answer 12

AMPA
- LTP can be produced either by increasing function of existing AMPA receptors through phosphorylation or by adding more AMPA receptors to the membrane of the synapse
NMDA
- the amount of NMDA receptors can determine if LTP or LTD will occur
- weakening/strengthening is input specific

Question 13

How does calcium affect LTP

Answer 13

high [Ca] favors LTP

Question 14

What role does CaMKII playin neural plasticity?

Answer 14

• it is critical for neuroplasticity
• it can autophosphorylate NMDA-mediated efflux of Ca for long periods of time
  •this allows for long-term changes in cellular function to occur
• acts as a molecular switch for long term changes

Question 15

What role does protein synthesis play in memory in the hippocampus?

Answer 15

• all long term memory requires protein synthesis
• transcription factors like CREB seem to be involved
  •CaMKII can phosphorylate CREB which induces transcription

Question 16

What is AMPA trafficking? what is the role of PSD-95

Answer 16

• AMPA trafficking is a common mediator of increasing and decreasing synaptic strength
• PSD-95 is a scaffolding protein that allows for more AMPA in the membrane

Question 17

Where else foes LTP and LTD occur?

Answer 17

It occurs not only in the hippocampus but also the neocortex in the medial temporal lobe
- cortical structure are dependent on NMDA receptors

Question 18

What is the importance of the dorsal striatum?

Answer 18

Procedural learning is associated with plasticity in the dorsal striatum
- NMDA antagonists and decreases in DA can block learning

Question 19

What is the importance of the cerebellum?

Answer 19

it is involved in procedural learning, fine-tuning motor functions

Question 20

What are the cells of the cerebellum? What are their function?

Answer 20

Purkinje cell (PC)
- major output of the cerebellum
- receives excitatory input from climbing fibers from the medulla
- carries information about what is going o
- PC receives input from granule cells through parallel fibers
Granule cells
- receives input from mossy fibers (neocortex structure)
- tells us what we want going on

Question 21

What is the PFC’s role in memory?

Answer 21

involved with working memory or “info in mind”
- critical for regulation of memory
- damage to PFC = confabulation
•person makes stuff up but actually believes it

Question 22

When is the amygdala activated

Answer 22

• highest activation when mixed emotions are present

- sensitive to both positive and negative expression

Question 23

what are the inputs and outputs of the amygdala?

Answer 23

• inputs from the association cortex and the hippocampus

- outputs to PFC, nucleus accumbens and hippocampus

Question 24

Describe the pathway of learning conditioned fear. Describe neuroplasticity

Answer 24

• Basolateral amygdala is the site that mediates association of US and CS. this projects to the cerebral cortex, nucleus accumbens, and hippocampus
• central nucleus projects to the brainstem and hypothalamus to produce ANS response
• plasticity works the same as LTP in hippocampus
  • NMDA critical for acquisition
  • AMPA mediates long term change

Question 25

What is the hippocampus’ role in fear?

Answer 25

Hippocampus encodes context information and spatial information
- how environmental clues determine context
• i.e. a snake in a zoo vs the wild

Question 26

What is the PFC’s role in fear?

Answer 26

• regulates the degree to which the amygdala expresses fear response
• involved in executive function and provides cognitive control
• critical for relearning during extinction training