Development of the Central Nervous System Practice Test 2026 – Complete All-in-One Guide for Exam Success!

Dorsal columns are white matter tracts that carry the central processes of the primary sensory neurons whose cell bodies reside in the dorsal root ganglia. As these fibers ascend, they synapse on second‑order neurons in the medulla. Those second‑order neurons act as interneurons that relay the sensory information onward toward higher brain centers. So the dorsal columns are involved in forming interneuronal (association) connections within the CNS, rather than motor neurons or glial cells. This is why association neurons is the best answer, since interneurons serve as the relay between incoming sensory signals and the next levels of processing in the brain.