Brains Change

Key Points

• Key feature of our brains: they change – learning (“plasticity”)
• A few ways of doing this
  • New neurons
  • Myelin sheaths
  • Modify neurons themselves
• An example of modifying neurons
  • Glutamate binds to two receptors: non-NMDA (plain) and NMDA (fancy)
  • Fancy – receptor and voltage-gated – activation leads to huge influx of sodium and calcium
  • The sudden click - a simplified picture of learning
  • Doogie Houser mouse experiment - mice with more plain receptors learn more quickly because they reach the threshold for the fancy receptor sooner
  • Long-term effects from calcium: more future release of glutamate, more receptors, more excitable receptors
• Things start to get complicated – back up, wise up
  • Final Thought: 100 billion neurons ›› 1015 synapses vs. 1011 stars

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