Introducing Astrocytes on a Neuromorphic Processor: Synchronization, Local Plasticity and Edge of Chaos

While there is still a lot to learn about astrocytes and their neuromodulatory role associated with their spatial and temporal integration of synaptic activity, the introduction of an additional to neurons processing unit into neuromorphic hardware is timely, facilitating their computational exploration in basic science questions and their exploitation in real-world applications. Here, we present an astrocytic module that enables the development of a spiking Neuronal-Astrocytic Network (SNAN) into Intel's Loihi neuromorphic chip. The basis of our module is an end-to-end biophysically plausible compartmental model of an astrocyte that simulates how intracellular activity may encode synaptic activity in space and time. To demonstrate the functional role of astrocytes in SNANs, we describe how an astrocyte may sense and induce activity-dependent neuronal synchronization, can endow single-shot learning capabilities in spike-time-dependent plasticity (STDP), and sense the transition between ordered and chaotic activity in the neuronal component of an SNAN. Our astrocytic module may serve as a natural extension for neuromorphic hardware by mimicking the distinct computational roles of its biological counterpart.