Dorsal column-medial lemniscus pathway

Dorsal column-medial lemniscus pathway (also known as the posterior column-medial lemniscus pathway or PCML pathway) is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, and proprioception (body position) from the skin and joints. It transmits information from the body to the primary sensory cortex in the postcentral gyrus of the parietal lobe of the brain.

File:Dorsal column-medial lemniscus pathway.png

Dorsal column-medial lemniscus pathway

Anatomy

The pathway consists of three neurons: the first-order neuron, the second-order neuron, and the third-order neuron. The first-order neuron resides in the dorsal root ganglia and sends its peripheral process to the skin and its central process into the spinal cord, where it ascends ipsilaterally in the dorsal column. The second-order neuron resides in the dorsal column nuclei, where it receives the central process of the first-order neuron and sends its axon over to the contralateral side via the internal arcuate fibers. The third-order neuron resides in the thalamus and sends its axon to the primary sensory cortex.

Function

The dorsal column-medial lemniscus pathway is responsible for transmitting sensory information about fine touch, vibration, and proprioception. The information is sent to the primary sensory cortex, where it is processed and integrated with other sensory information.

Clinical significance

Damage to the dorsal column-medial lemniscus pathway can result in a loss of proprioception and fine touch sensation. This can lead to a condition known as sensory ataxia, which is characterized by an unsteady gait and a lack of coordination.

See also

• Sensory system
• Spinal cord
• Thalamus
• Parietal lobe