midbrain

American  

[mid-breyn] / ˈmɪdˌbreɪn /

noun

Anatomy.

1. the middle of the three primary divisions of the brain in the embryo of a vertebrate or the part of the adult brain derived from this tissue; mesencephalon.

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midbrain British  

/ ˈmɪdˌbreɪn /

noun

1. the nontechnical name for mesencephalon

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midbrain Scientific  

/ mĭd′brān′ /

1. The middle part of the vertebrate brain. In most animals except mammals, the midbrain processes sensory information. In mammals, it serves primarily to connect the forebrain with the hindbrain.

2. Compare forebrain hindbrain

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Etymology

Origin of midbrain

First recorded in 1870–75; mid- + brain

Example Sentences

The prefrontal cortex helps guide decisions in fearful situations, while deeper areas such as the periaqueductal gray in the midbrain control responses like freezing or fleeing.

From Science Daily • Apr. 4, 2026

Published in Science Advances, the study reports that several methods used to grow midbrain cells also generated unwanted cells originating from other brain regions.

From Science Daily • Nov. 3, 2025

This "comprehensive reference map" now serves as a global standard for evaluating how accurately midbrain models match real human biology.

From Science Daily • Nov. 3, 2025

“It’s only been in the past few years, where the midbrain has gotten more attention from neuroscientists studying social communication,” Bass said in an earlier statement.

From Salon • Jan. 8, 2024

On account of the great size of the cerebrum, the midbrain is entirely concealed from view when the other parts occupy their normal positions.

From Physiology and Hygiene for Secondary Schools by Walters, Francis M.