Spike‑timing dependent plasticity

Pair a presynaptic spike with a postsynaptic spike. When pre comes shortly before post the synapse strengthens (LTP); when post comes before pre it weakens (LTD). Watch an NMDA receptor detect the timing, and the Bi & Poo curve build up point by point.

Protocol run in order

Timing

← post before prepre before post →

Readout

Synapse AΔt +10 ms
Order—
Coincidence—
Change per pairing—
Synapse BΔt −10 ms
Order—
Coincidence—
Change per pairing—

The cell head size = synaptic strength

glutamate bound (pre) Mg²⁺ block relieved (post) Ca²⁺ entering

The STDP curve  same axes as Bi & Poo (1998)

Synaptic strength % of baseline

Inside one pairing

glutamate bound (after pre) Mg²⁺ block relieved (after post) Ca²⁺ influx = product of the two