I hypothesize that synapsembles may serve a dual role. First, they limit the lifetime of neural words to subsecond to seconds time scales. Such self-tuned synapses are likely critical in the build up and termination of assembly activity. This process may be brought about by the depressing excitatory synapses among the active assembly members and/or by potentiated inhibition of the recruited interneurons, assisted by intrinsic neuronal mechanisms, such as firing history-dependence of spike threshold (Henze and Buzsáki, 2001). Second, synapsembles link neuronal words separated by cessation of spiking activity (Buonomano and Maass, 2009). Depressing the inhibitory connections and/or potentiating excitatory synapses between members of the receding and trailing cell assemblies (Wang et al., 2006) may achieve such linking. Clearly, the postulated contribution of self-tuned synaptic plasticity to neural syntax could benefit from future experimental and computational analyses.
