Read the equation
Between spikes, the trace decays with time constant τ_AMPA. Each ideal impulse increases it by one. The code implements those two operations separately: receive_spike adds one and step multiplies by exp(−dt/τ), giving the exact between-spike decay.
Terms & definitions
| Term | Meaning in this source |
|---|---|
| s | Synaptic trace |
| tau_AMPA | Decay time constant |
| t_j | Presynaptic spike times |
How it works
Read the definition from its right-hand expression to the quantity on the left. Its surrounding source records the intended input, state, or parameter context. Where the source leaves an operation unspecified, this page preserves that gap.
Assumptions & limits
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Original context
Read the surrounding source passage
// ═══════════════════════════════════════════════════════════════════════════════
// SYNAPTIC TRANSMISSION
// Models for AMPA, NMDA, and GABA receptors
// ═══════════════════════════════════════════════════════════════════════════════
// AMPA Receptor (fast excitatory)
// I_AMPA = g_AMPA * s * (V - E_AMPA)
// ds/dt = -s/τ_AMPA + Σ_j δ(t - t_j)
struct AMPASynapse {
float g_max = 0.35f; // nS - Maximum conductance
float E_rev = 0.0f; // mV - Reversal potential
float tau = 2.0f; // ms - Decay time constant
float s = 0.0f; // Synaptic variable
float current(float V_post) const {
return g_max * s * (V_post - E_rev);
}
Exact original notation
ds/dt = -s/τ_AMPA + Σ_j δ(t - t_j)