Eric Kandel: Synaptic Changes
in the Hippocampus
Johnia MurrayImani Ross
IB Psychology II1A
Kandel was a pioneer in moving the study of
the mind from an investigation of behavior to an investigation of impulses
Deals with learning and memory in the hippocampus of the brain
Memories don’t reside in a single, specific spot of the brain
Neural (neurons->synapses->impulses) change occurs between the synapses
Background Info
What is this?
Sites at the end of a neuron Place where nerve cells communicate with one
another Use neurotransmitters as messages to each
other
Synapses
1982 Experiment
Eric Kandel and James Schwartz Observing changes in sending neurons Used a California sea snail, the Aplysia
Getting Down to Specifics. . .
A California Sea Snail Observed changes in sending neurons Has 20,000+ unusually large nerve cells Classically conditioned (Ch. 8 from last year)
the snail to withdraw its gills when water is squirted at it
Learning occurs Snail releases serotonin at certain synapses
Becomes more efficient at transmitting signals
Aplysia Study
NOVAscienceNOW – A Memorable Snail - PBS http://
www.youtube.com/watch?v=yLa-cXg8BwM
Aplysia Study cont’d
Increased synaptic efficiency makes for a more
efficient neural circuit Sending neurons now need less imprinting to
release neurotransmitters The receiving neuron receptor cites may increase Long Term Potentiation
a long-lasting strengthening of the response of a postsynaptic nerve cell to stimulation across the synapse that occurs with repeated stimulation and is thought to be related to learning and long-term memory
Synapses and Memory
LTP provides a neural basis for learning and
remembering associations (reference to Ch.8) Drugs that block LTP, interfere with learning At least 40 cognitive enhancers are currently
in some phase of development or clinical trial Target market: those with Alzheimer’s Disease,
with mild cognitive impairment
Synapses and Memory cont’d
Hippocampus: Where is it located?
Where initial events must come here in order to
be turned from short term to long term memory Short term memory is processed in the
hippocampus Neurons have to cross over the synapses to
leave a mark or ‘tag’ Declarative Memory
A memory for fact and events People, places and objects
Hippocampus
Contains a cognitive map of external
environment Registers spatial information
Space surrounding you (or animals) Registers single sensory modality
Sight, sound, touch or pain
Hippocampus cont’d
Synaptic changes affect our learning ability
and memory Memories are stored in different places A lot of work is done in the hippocampus Don’t do drugs Snails are more than just slimy creatures that
look nasty There’s still a lot to be discovered about the
brain
In short. . .
Myers, David G. (2006) Psychology (AP
Edition). :Macmillan – Worth Publishers. Mayford, Mark; Siegelbaum, Steven A; Kandel,
Eric R. (2012) Synapses and memory storage. CSH Perspectives in Biology, 4(6). Retrieved from http://cshperspectives.cshlp.org/content/4/6/a005751.full
Reference List