Figure 2.

Signaling cascades involved in t-LTP induce by different STDP paradigms at distinct chemical synapses. Specific STDP protocols activate different signaling and expression mechanisms in pre- and postsynaptic parts of the synapse to induce specific types of synaptic plasticity. (A) Putative dopaminergic (DA) signaling mechanisms underlying t-LTP induced either with a canonical 1:1 paradigm or with a burst paradigm at low repeat number. Pre-, post- and extrasynaptic mechanisms might be involved. (B) BDNF/TrkB signaling involved in STDP induced by burst protocols. t-LTP induction with a 1:4 protocol recruits autocrine postsynaptic mechanisms by BDNF and TrkB signaling. (C) NA, ACh or endocannabinoid (eCB) signaling can contribute by pre- and postsynaptic mechanisms similar to DA, in regulating the efficacy of t-LTP at distinct and/or overlapping ultrastructural synapses. Lower panel: description of symbols.