The Mood of a Worm

摘要

The human nervous system is a vastly complex network of functionally interconnected cells whose detailed structure is at present beyond reach. All our actions, calculations, feelings, memories, dreams-consciousness itself-emerge from its workings. To understand this colossal, enigmatic structure, experimentally amenable model animals with tractable nervous systems many orders of magnitude smaller are studied. A popular choice has been the worm Caenorhab-ditis elegans, a nematode 1 mm long with a nervous system containing fewer than 400 neurons.