Preganglionic fibers connected the ganglion to the central nervous system. Doctor Julian Bashir claimed he mistook a preganglionic fiber for a postganglionic nerve during the oral exam phase of his Starfleet Medical finals. The mistake meant Bashir did not score high enough to be valedictorian of his class and became salutatorian instead. (DS9: "Emissary", "Q-Less", "Distant Voices") In 2373, The Doctor repaired the damage to the preganglionic fibers in Tom Paris' spinal column after Paris had been attacked by members of the Swarm species. (VOY: "The Swarm")