Memory: the processes through which learned information is stored

Learning: the acquisition of an altered behavioral response due to an

environmental stimulus

Recall: the conscious or unconscious retrieval process through which this

altered behavior is manifest

Suggested Reading

• The Seven Sins of Memory by Daniel Schacter

• Mechanisms of Memory by David Sweatt• Grain Brain by David Perlmutter• Memory From Mind to Molecules by

Squire and Kandel

https://www.youtube.com/watch?v=5cKtSg8vPiM

Neuron

Marina Chicurel and Christopher DeFranceo, The Inner Life of Neurons: An empire of semi-independent domains, The Harvard Mahoney Neuroscience Institute Letter: On The Brain, Vol. 4 (Spring, 1995), http://www.med.harvard.edu/publications/On_The_Brain/Volume4/Number2/SP95In.html

Neurons shapes and sizes from Univ. of Washington

Ion Channels

John Travis, Channel Surfing: Atomic-resolution snapshots illuminate cellular pores that control ion flow, Science News Online, Vol. 161 (March 9, 2002), http://www.sciencenews.org/articles/20020309/bob8.asp

Christof Koch, Biophysics of Computation: Information Processing in Single Neurons Oxford Univ. Press, Oxford, 1999, p. 7

Action Potential

adapted from J. Timothy Cannon, http://academic.uofs.edu/faculty/cannon/sp/02/ActionPotential.html, retrieved 3/30/04

http://www.blackwellpublishing.com/matthews/channel.html

Synapse

Dale Purves, George Augustine, David Fitzpatrick, Lawrence Katz, Anthony-Samuel LaMantia, James McNamara, and Mark Williams, Neuroscience, Sinauer Associates, Sunderland, Massachusetts, 2001, p. 142.

Cartoon

Expression of LTP• possible presynaptic mechanisms

– increased probability of transmitter release in response to a presynaptic action potential

– more transmitter released due to more sites of release – more transmitter released due to increased size of vesicles

containing neurotransmitter – a presynaptic mechanism requires a retrograde messenger (e.g.

nitrous oxide) to signal postsynaptic activity to the presynaptic terminal

• possible postsynaptic mechanisms – increased sensitivity to transmitter due to more postsynaptic

receptors for the neurotransmitter – increased sensitivity to transmitter due to increased

conductance of individual receptors • evidence points to a combination of both possibilities

Glu

Reuptake

Retrograde Signal

Presynaptic = Altered• Neurotransmitter amount in vesicles• Number of vesicles released• Kinetics of release• Glutamate reuptake• Probability of vesicle fusion

Postsynaptic = Altered• Number of AMPA receptors• Insertion of AMPA receptors• Ion flow through AMPA channels• Membrane electrical properties

Additional possibilities include changes in number of total synaptic connections between two cells

Membrane Properties

Release

Binding

Potential Sites of Synaptic Modification in LTP

ReleaseProcess

*PKC

AMPAR

NMDAR

Phosphorylation& Insertion

Ca++

RetrogradeMessenger?

*CaMKII

*PKMzeta

*PKC

Synaptic Tag

K+ Channels

Protein Synthesis

?

?

* = Persistently Activated

CytoskeletonChanges

?

?

1

1

1

1

2

2

2

3

3

Mechanisms for E-LTP

Activity-dependent Regulation of Gene Expression

How to reduce chances of Dementia and Alzheimer’s

• Diet – low calorie, high fat, high protein, low carb, high Omega-3 low Omega-6, blueberries, anti-oxidants

• Physical activity• Mental activity• Cholesterol levels – high cholesterol

good?• Hormone levels

Need volunteers

• 2-3 actors• 1 still photographer• 1 video photographer• Need to be here 30 minutes early next

week

Sins of Memory (Omission)

• Transience – weakening or loss of a memory over time

• Absent-mindedness – info not registered due to distraction

• Blocking – search for info we know, but can’t retrieve

Sins of Memory - Commission

• Misattribution – assigning a memory to the wrong source

• Suggestibility – memory implanted as a result of suggestions

• Bias – influence of current knowledge and beliefs on memory

• Persistence – repeated recall of disturbing memory that we would rather forget