Schematic of biological neuronal network and an organic nanowire (ONW) synaptic transistor (ST) that emulates a biological synapse. The yellow conductive lines and probe (A′) mimic an axon (A) that delivers presynaptic spikes from a pre-neuron to the presynaptic membrane. The mobile ions in the ion gel move in the electrical field, analogous to the biological neuron transmitters in the synaptic cleft; the field later induces an excitatory postsynaptic current (EPSC, light blue line) in the biological dendrite (B). An ONW (B′) combined with a drain electrode (yellow surface) mimics a biological dendrite (B). EPSC (light green line) is generated in the ONW in response to presynaptic spikes and is delivered to a post-neuron through connections to the drain electrode. (credit: Wentao Xu et al./Science Advances)