Short-Term Synaptic Plasticity
Tsodyks-Markram model: depression (D) vs facilitation (F), paired-pulse ratio
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PPR (2nd/1st)
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Mode
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x̄ (resources)
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ū (utilization)
Tsodyks-Markram
U (base util)
0.20
τ_rec (ms)
500
τ_fac (ms)
10
A_syn
1.00
x=resources (1=full). u=utilization. Release = u·x·A. Depression: τ_fac<<τ_rec. Facilitation: τ_fac>>τ_rec and small U.
Stimulation
Frequency (Hz)
20
Train length
8
Jitter (ms)
1.0
Regular spike train at given frequency. Jitter adds temporal noise. Observe steady-state EPSPs at train end.
Presets
Depression
Facilitation
Mixed
Depression: large U, fast resource depletion. Facilitation: small U, slow τ_fac builds up utilization. Mixed: both timescales.