The LTP window as a function of the LTP threshold under the triplet protocol without the dynamic time constant ().

The time between the pre-synaptic spike and the second post-synaptic spike was . Post-synaptic spikes were separated by . is defined by the onset (lower curves) and offset (upper curves) of LTP as a function of , as shown in Figure 4. Black and grey curves show results for inter-pairing frequencies of 5 Hz and 0.5 Hz respectively. To be consistent with the data by [19], the black and grey curves should not overlap from . Without the dynamic time constant, the model requires biologically implausible parameter values to reproduce the data (panels C and D, see text). (A) The LTP window for parameter values justified in the Methods (, ). (B) The LTP window for and . (C) An implausibly long baseline time constant of decay approximates the data (, ). (D) An implausibly long time constant of decay of the BAP tail approximates the data, though expands slightly in the anti-causal direction (, ).