3. Long Term Memory
4. Eric Kandel
Calcium = ion, carries 2 charges voltage sensitive channels on neuron terminals
- Binds to calmodulin, binds to vesicles releasing some from filaments and inducing others to bind to the
presynaptic membrane and to empty their contents.
The Cellular Basis of Learning
- Eric Kandel
○ Nobel Prize in 2000
○ Wrote "In Search of Memory"
"Without memory we would be nothing"
Aplysia - california sea slug
□ Ways a couple pounds
□ Have orgies.
100, 000 neurons
□ Abdominal ganglia = 20 000 neurons
Runs the circuitry in its gill
Behavior = gillretracts when touched
○ Horses weren't designed for humans
○ How do we get them to get used to us?
○ Define: the response to a stimulus weakens with repeated presentation
Given that a particular stimulus elicits a response, repeated applications of the stimulus results in
If the stimulus is withheld, the response tends to recover over time (spontaneous recover)
If repeated serious of habituation training and spontaneous recovery are given, habituation becomes
successively more rapid
Other things being equal, the more rapid the frequency of stimulation, the more rapid and/or more
pronounced is habituation
The weaker the stimulus, the more rapid and/or more pronounces is habituation. Strong stimuli may
yield no significant habituation
The effects of habituation training may proceed beyond the zero or asymptotic response level
Habituation of response to a given stimulus exhibits stimulus generalization to other stimuli.
○ QUESTION: what happens to gill response after repeated stimulation?
1. Gill withdraws from water jet
2. Gill no longer withdraws from water jet demonstrating habituation
Results: the sensory neuron stimulates the motor neuron to produce gill withdrawal before
With habituation, the influx of calcium ions in response to an action potential decreases
Resulting in less neurotransmitter released at the presynaptic membrane
And less depolarization of the postsynaptic membrane
Conclusion: withdrawal response weakens with repeated presentation of water jet
(habituation) owing to decreased Calcium influx and subsequently less
neurotransmitter release from the presynaptic axon terminal.
Study this calcium channel and its changes
– Should follow the same rule: if you come back the next day, should be
letting calcium back in
– If you do it repeatedly over days, better effect
– A lot of