“…The paper by Delattre V et al describes how the timing of network activity in relation to that of spikes can determine the direction of plasticity (Delattre et al, 2015 ). The paper by Faghihi and Moustafa shows how Hebbian plasticity and fast retrograde signaling can interact to generate highest efficiency to encode differences in input stimuli (Faghihi and Moustafa, 2015 ).…”