Fig. 1.

Illustration of the basics of our model. A: schematic of the single compartment model used in this study. The various ligand- and voltage-gated channels used in the model are depicted as arrows. B: properties of N-methyl-d-aspartate receptor (NMDAR) current used in the model. The current through the receptor as a function of membrane voltage shows the magnesium dependent voltage block at hyperpolarized voltages. Inset: time course of a typical NMDAR excitatory postsynatic potential (EPSP). C: functional form of the plasticity-regulating Ω-function plotted for various concentrations of intracellular calcium. D: evolution of weight w, when the model was stimulated with 900 pulses of multiple frequencies, plotted as a function of time. It may be noted that the evolution approximates an exponential. The color codes for various frequencies translate to E as well. Because 900 pulses of a low-frequency stimulus ended later than 900 pulses of a high-frequency stimulus, the endpoints are variable. It may be noted that at the end of the stimulus protocol, the weight parameter increased (potentiation) for frequencies that are approximately >15 Hz while decreasing (depression) for frequencies lesser than that value. E: plot obtained by tracking percentage change in weight w after 900 pulses of stimulus at various frequencies. The colored dots represent the values obtained from D for corresponding frequencies.