Fig. 3
From: Heterosynaptic plasticity-induced modulation of synapses
Determinants of the direction of synaptic plasticity. A The high and low frequency of tetanization determines the kind of plasticity. B Activation of the synapses 10–20 ms before or after the firing of the postsynaptic cell leads to the induction of LTP or LTD, respectively. C High and minor augmentation of [Ca2+]in could induce LTP and LTD, respectively. D Weak inputs (light green input) with low initial release probability (RP) were classically potentiated, while strong inputs (dark green input) with a high initial release probability were typically depressed or did not alter (from Turrigiano et al., 1998)