Gracile fasciculus

The gracile fasciculus represents the first order neurons of the dorsal column medial leminiscal sensory pathway, that transmit the sensory information of vibration, conscious proprioception, and 2-point discrimination from the lower extremities. Hence, it can be found throughout the length of the spinal cord. The gracile fasciculus ascends in the dorsal spinal cord and medulla to terminate by synapsing with the gracile nuclei (in the gracile tubercle).

Don’t confuse the gracile fasciculus with the cuneate fasciculus, which also represents first order neurons of the dorsal column pathway, however, the cuneate fasciculus differs as it transmits the same piece of information from the upper extremities (sparing the head). Consequently, the cuneate fasciculus is found at spinal segment level T6 and above only (while being absent in the lower spinal cord). Furthermore, the cuneate fasciculus stays lateral to the gracile fasciculus all the time as it ends up by synapsing with the cuneate nuclei (in the cuneate tubercle).

Both fasciculi–gracile and cuneate –are separated from each other by an intermediolateral sulcus.