commissure

anatomy

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June 24, 2026

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A commissure is an anatomical term referring to a point or line where two parts join or connect. This can be seen in structures like adjacent heart valves. In the brain and spinal cord, a commissure is a band of nerve tissue that connects different areas.1

For example, the corpus callosum is a thick band of white matter that connects the two cerebral hemispheres, allowing them to integrate information. The brain also has a "soft commissure," which is gray matter connecting the optic thalami across the third ventricle. Additionally, "postcommissures" are bands of white matter located at the back of the third ventricle.234

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nervous system
Simple bilateral systems
…a broad connection called a commissure. Longitudinal nerve cords, usually three to five pairs, extend posteriorly from the brain; they are connected by transverse commissures, and smaller, lateral nerves extend from the cords. The lateral nerves give rise to the peripheral nerve plexuses. The submuscular nerve plexus—consisting of sensory cells,…
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…a broad connection called a commissure. Longitudinal nerve cords, usually three to five pairs, extend posteriorly from the brain; they are connected by transverse commissures, and smaller, lateral nerves extend from the cords. The lateral nerves give rise to the peripheral nerve plexuses. The submuscular nerve plexus—consisting of sensory cells,…
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