Learning & Memory - Drewes

Question 1

What is the most common “memory enhancing” drug according to Dr. Drewes?

Answer 1

Ritalin

Question 2

How do synapse establish final connections?

Answer 2

“Awakening” of synaptic transmission/activity during development

Question 3

What is the effect on the synapse if the presynaptic and postsynaptic neurons are active simultaneously?

Answer 3

Strengthened

“Neurons that fire together wire together.”

Question 4

What is the effect on the synapse if presynaptic and postsynaptic activities are not linked?

Answer 4

Weakened

“Neurons that fire out of synce loose their link.”

Question 5

NMDA receptors are activitated by what simultaneous activities?

Answer 5

presynaptic and postsynaptic activity

Question 6

When does “synaptic plasticity” occur in relation to the NMDA receptors?

Answer 6

• presynaptic glutamate release causes depolarization sufficient to displace Mg²⁺ ions
• Ca²⁺ is admitted by the NMDA receptor
  
  • triggers enhanced synaptic effectiveness –> SYNAPTIC PLASTICITY occurs

Question 7

What happens in long term potentiation following a strong NMDA receptor stimulation?

Answer 7

• post-synaptic response is raised due to presynaptic shock
• strong activation recruits more AMPA receptors
• newly increased baseline level for post-synaptic response

Question 8

What happens in Long Term Depression when weak NMDA receptor activation occurs?

Answer 8

• AMPA receptors decline
• neurons lose their link
• less post-synaptic response

Question 9

What is the broad definition of memory and learning according to Dr. Drewes?

Answer 9

Adaptive change on the part of an organism in response to an environmental input

(simply: response to a stimulus)

Question 10

What is the difference between learning and memory?

Answer 10

Learning = acquisition of new info, knowledge, or skill

Memory = retention of learned info

Question 11

What is the time range for short-term memory, long-term memory, and memory consolidation?

Answer 11

• Short-term = seconds - minutes (maybe an hour)
• Long-term = hours - months
• Memory consolidation = months - lifetime

Question 12

What kind of memory can be interrupted by protein synthesis inhibitors?

Answer 12

Long-term memory & Memory Consolidation

Question 13

What general area of the brain is memory located?

Answer 13

Hippocampus

Question 14

What is the Engram?

Answer 14

physical location in the brain where memory is stored

(biological neural network or cell assembly)

Question 15

What is a cell assembly?

Answer 15

Group of simultaneously active neurons

(such as those found in the Engram)

Question 16

What organism was used as a animal model to test the molecular mechanisms of memory?

Answer 16

Aplysia californica

Question 17

What two functions were identified from the Aplysia californica concerning memory?

Answer 17

• Gill-withdrawal reflex
• Habituation

Question 18

What was the first gene identified as important for memory?

Answer 18

Phosphodiesterase

(mutation = “dunce”)

Question 19

What is the molecular mechanism for short-term memory in high organisms like mammals?

Answer 19

• cAMP activates Protein Kinase A (PKA)
• PKA phosphorylates K⁺ channels to become more active
  
  • depolarize easier

Question 20

What is the molecular mechanism for Long-term memory in high organisms like mammals?

Answer 20

• cAMP activates Protein Kinase A (PKA)
• PKA activates MAPK Kinase
• PKA and MAPK activate Cyclic AMP Response Binding protein (CREB)
• CREB produces proteins to expand synapses, strengthen synapses, and increase contacts
  
  • results in growth of memory

Question 21

What two additional protein kinases were found to enhance memory?

Answer 21

CaMKII

&

CASK: CaM Serine Kinase (regulator of CaMKII)

Question 22

What is the latest protein-coding gene identified in 2014 that is likely a cell adhesion molecule, involved in long term potentiation/synaptic plasticity, and affects cortical thickness?

Answer 22

Neuroplastin (NPTN)

-King’s College London

Question 23

Is there more synaptic contacts (bigger, fatter, longer) in a younger person or older person?

Answer 23

Younger