In the late 1960s, neuroscientists aiming to understand how the human brain worked were searching for a simpler network of neurons to study; one that reliably activated a stereotypical response, in which they would be able to identify the sensory nerve that detects the stimulus and the neural interchange that passes the message to a motor nerve. The stomatogastric ganglion (STG) of crustaceans fitted the bill particularly well as it is an independent network with a countable number of neurons (about thirty), a simple single input nerve, and an output to accessible stomach muscles.
Original Article: [In Context] Eve Marder: the world is her lobster