The interplay of synaptic plasticity and scaling enables the self-organized allocation of multiple memory representations

It is commonly assumed that memories about experienced stimuli are represented by groups of highly interconnected neurons called cell assemblies. This requires allocating and storing information in the neural circuitry, which happens through synaptic weight adaptation. It remains, however, largely unknown how memory allocation and storage can be achieved and coordinated to allow for a faithful representation of multiple memories without disruptive interference between them. In this theoretical study, we show that the interplay between conventional synaptic plasticity and homeostatic synaptic scaling organizes synaptic weight adaptations such that a new stimulus forms a new memory and where different stimuli are assigned to distinct cell assemblies. The resulting dynamics can reproduce experimental in-vivo data, focusing on how diverse factors as neuronal excitability and network connectivity, influence memory formation. Thus, the here presented model suggests that a few fundamental synaptic mechanisms may suffice to implement memory allocation and storage in neural circuitry.