Notes

Short-term Plasticity: Paired Pulse Facilitation Paired activations of a synapse onto a CA1 neuron. "Residual Ca2+"in terminal for 10 to 100 ms after first stimulus increases probability of release.

Post Tetanic Potentiation and Long-Term Potentiation PTP believed to be caused by a large accumulation of Ca2+ in the terminal caused by a high frequency tetanic stimulation.

Recording of LTP in a Hippocampal Slice & of LTD in the Hippocampus

Summary of LTP and LTD

• LTP
  • LTP after titanic stimulation is (high) frequency dependent.
  • LTP involves multiple mechanisms across time all of which induce long-term synaptic strengthening.
  • LTP mechanisms last from 30min to several hours, but do not involve protein synthesis.
  • LTP mechanisms lasting longer than a few hours require protein synthesis.
• LTD
  • LTD after titanic stimulation is (low) frequency dependent.
  • LTD also involves several different mechanisms acting in concert to induce synaptic depression.
  • LTD and LTP act in concerto to change information coding and to implement new memories in the brain.
  • STDP is thought to arise from the same mechanisms governing LTP and LTD.

Synaptic plasticity, the Hebbian Synapse

Synaptic Plasticity - A Short Recap of Synaptic Function

Plasticity (LTP) at the Synapse

1. Synapse size changes. (Long-term)
2. AMPA/NMDA ratio changes / More vesicles. (Long-term)
3. Number of spines changes. (Very Long-term)

Time Scales of Synaptic Plasticity

Synaptic Plasticity - The NMDA Receptor

The Role of Calcium in LTP/LTD