Path After neurons carrying
somatosensory proprioceptive or fine touch information
synapse at the gracile and cuneate nuclei, axons from
second-order neurons
decussate at the level of the medulla and travel up the brainstem as the medial lemniscus on the contralateral (opposite) side. It is part of the
posterior column-medial lemniscus pathway, which transmits touch, vibration sense, as well as the
pathway for proprioception. The medial lemniscus carries axons from most of the body and terminates by synapsing with
third-order neurons in the
ventral posterolateral nucleus of the
thalamus. at the level of the
mamillary bodies. Sensory axons transmitting information from the head and neck via the
trigeminal nerve synapse at the
ventral posteromedial nucleus of the
thalamus.
Location through the brainstem The cuneate and gracile nuclei reside at the
closed (lower) medulla, so the medial lemniscus is not formed at this level. Fibres from these nuclei will pass to the contralateral side of the brainstem, as the
internal arcuate fibres. In the midbrain, it is situated dorsal to the
substantia nigra, and medial to either
red nucleus. ==Additional images==