•The human genome is like a book that, if read carefully, can be used to create a complete human body.
• However, for the body to be truly alive, it must be able to adapt and respond on its own – something that genes cannot do.
• Learning is what allows humans to take the instinctive behaviors of animals and build upon them.
• James Mark Baldwin was an American evolutionary theorist who argued that learning is more advanced than instinct.
•The sea slug is a simple creature that can learn things like habituation, sensitization, and associative learning.
• These reflexes and the learning that modifies them occur in the abdominal ganglion, a small nervous substation in the belly of the slimy creature.
• The man behind these experiments, Eric Kandel, had a motive other than bothering slugs- he wanted to understand the basic mechanism by which learning occurred.
• What changes occur to nerve cells when the brain (or abdominal ganglion) acquires a new habit or change in behavior?
Kandel’s attention quickly focused on synapses between neurons. Learning seems to be a change in their properties.
• Thus when a sea slug habituates to false alarm, for example,the synapse between receiving sensory neuron & neuron moving gill is weakened . Conversely ,when sensitized to stimulus ,the synapse is strengthened .
• Gradually & ingeniously ,Kandel & colleagues homed in on particular molecule lay at heart of weakening/strengthening of synapses :cyclic AMP . They discovered cascade of chemical changes all centered around cyclic A M P
•Volado is a gene needed for learning
• The protein it produces binds cells together, hinting that memory may be the physical strengthening of connections between neurons
• Long-term potentiation (LTP) is a key event in memory formation, and integrins are necessary for its maintenance
• The hippocampus stores memories, but they are first formed in the perirhinal cortex