neocortex (Fujisawa et al., 2009; Markram et al. 1998). Indeed, a balance between depressing and potentiating synapses in model networks is needed for stability. At the same time, networks with dynamic synapses can respond robustly to external inputs yet return to baseline activity shortly after the perturbation (Sussillo et al., 2007). Analogous to the assembly of spiking neurons, a particular constellation of synaptic weights in a defined time window can be conceived of as an assembly of synapses or ‘synapsemble’. There are orders of more synapses in the brain than the number of its neurons. In addition, dynamic synapses signal a continuous relationship between neurons, offering a much richer source of communication by synapsembles than by the all or none spikes or discharge rates.
