The influence of stimulation timing on late-associativity with (<i>N</i>, <i>s</i>_<i>E1</i>) = (5, +10).

The figure shows the same contents as S1 Fig. However, the number of competing synapses N and the stimulation timing at synapse E1 sE1 are different. (TIF)</p

The dynamics of each variable in e-LTP.

(A) The normalized activity level of stimuli-dependent Ca2+ cascades in the spine Us (black). The scaled intensity of synaptic tag Tp[n] (red dashed line). The green arrow denotes the timing of the e-LTP–inducing stimulation protocol. (B) The scaled concentration of translation sources Md (black). (C) The normalized activity level of PRP synthesis cascades in the dendritic compartment Ud (black). To improve visualization, Ud was scaled to 1/5. The scaled concentrations of synaptically trapped PRPs Ps (red) and PRPs in dendrites Pd (green) are presented. (D) The spine head volume W (black). State variable of synaptic plasticity Z (red dashed line).</p

The influence of stimulation timing on late-associativity with (<i>N</i>, <i>s</i>_<i>E1</i>) = (10, -10).

The figure shows the same contents as S1 Fig. However, the number of competing synapses N and the stimulation timing at synapse E1 sE1 are different. (TIF)</p

The influence of stimulation timing on late-associativity with (<i>N</i>, <i>s</i>_<i>E1</i>) = (15, +10).

The figure shows the same contents as S1 Fig. However, the number of competing synapses N and the stimulation timing at synapse E1 sE1 are different. (TIF)</p

The influence of stimulation timing on late-associativity.

The schematic diagram of our simulation experiment II. The horizontal axis denotes time (min). The black arrow at 0 min denotes the start of the l-LTP–inducing stimulation protocol at synapse L1. Other arrows indicate the stimuli in the e-LTP–inducing stimulation protocol at synapses E1–E15. Stimulus patterns are characterized by sE1 and dsE. sE1 denotes the stimulation timing at synapse E1. We defined stimulus patterns in which all e-LTP–inducing stimulation protocols were conducted before the l-LTP–inducing stimulation protocol as the left window (sE1 sE1 > 0). dsE is the stimulus interval. (B) Spine head volumes of synapses E1–E15 180 min after stimulation with different stimulus patterns. Marker denotes the log-scale basal PRP level in the simulation. (C) Four types of enhancement tendencies. Types I–IV alternatively appear depending on the basal PRP level in a specific order (see S1–S6 Figs for the enhancement tendencies under all stimulus patterns). (D) Basal PRP level dependency of the intragroup mean and standard deviation. Each marker line denotes a different stimulation interval. Background color denotes the range of basal PRP levels in which each type dominantly appears. Type I is red, Type II is blue, Type III is green, and Type IV is yellow.</p

Temporal asymmetry of the STC window simulated by our model.

(A) The schematic diagram of our experiment for simulating the temporal STC window. (B) Schematic illustration showing that the asymmetry of the STC temporal window is attributable to the difference in the time constants of the synaptic tag and newly synthesized PRPs. Yellow areas indicate the coexistence of synaptic tags and newly synthesized PRPs. The number of PRPs captured by synapses increases as the area increases. (C) A simulation result. Our model correctly simulated the asymmetry of the STC temporal window [12]. The horizontal axis denotes the relative timing of the e-LTP–inducing stimulation protocol at synapse E1 from the l-LTP–inducing stimulation protocol at synapse L1. The vertical axis denotes the spine head volume of E1 180 min after the e-LTP–inducing stimulation protocol to E1.</p

The influence of stimulation timing on late-associativity with (<i>N</i>, <i>s</i>_<i>E1</i>) = (5, -10).

The horizontal axis denotes the labels of synapses. The vertical axis denotes the spine head volume of E1-En 180 min after the e-LTP–inducing stimulation protocol. The basal PRP level (log10 scale) is shown at the top of each panel. Each marker line indicates different stimulus intervals. (TIF)</p

Model parameters.

Model parameters.</p

The dynamics of each variable with the e-LTP–inducing stimulation protocol under abundant PRP levels.

The variables illustrated in (A)–(D) are the same as those described in the caption of Fig 2. For (A), the green arrow denotes the timing of the e-LTP–inducing stimulation protocol.</p

Influence of the number of competitive synapses and basal PRP level on the STC window.

(A) Green circles and red squares indicate the volume of synapses E1 and L1, respectively, after potentiation. The horizontal axis is the execution timing of the e-LTP-inducing stimulation protocol relative to l-LTP–inducing stimulation. (B) The spine head volumes of E1 and L1 for different basal PRP levels and numbers of competitive synapses. In each panel, the scale of the vertical and horizontal axes is the same as that in (A). The panel with a red frame is the same as that in (A). “×10” in the basal PRP level means 10 times the standard value of .</p