mid·​brain | \ ˈmid-ˌbrān How to pronounce midbrain (audio) \

Definition of midbrain

: the middle of the three primary divisions of the developing vertebrate brain or the corresponding part of the adult brain between the forebrain and hindbrain that includes the tectum, tegmentum, and substantia nigra

called also mesencephalon

— see brain illustration

Examples of midbrain in a Sentence

Recent Examples on the Web When recalling memories, the thalamus — a small structure within the brain between the cerebral cortex and the midbrain — is activated. Ebony Williams, ajc, 14 Apr. 2022 Treatment to book: NuCalm is, essentially, a sophisticated power nap, promoting relaxation in 30 to 90 minutes with patented technology that interrupts stress at the midbrain. Rona Berg, Devorah Lev-tov, Robb Report, 15 Mar. 2022 The midbrain is responsible for our fight, flight and freeze reactions. Dr. Denise Trudeau-poskas, Forbes, 7 Dec. 2021 The scientists were able to create a synthetic midbrain through stem cells that had been modified to mimic the genetic risk factors for a brain disease like Parkinson’s. Sy Mukherjee, Fortune, 9 Sep. 2021 In both situations, the neurons in the midbrain's substantia nigra and ventral tegmental area flared up in response to the images. Rasha Aridi, Smithsonian Magazine, 24 Nov. 2020 Postmortem analysis of his brain showed massive loss of nerve cells in two regions of the thalamus, a structure about the size of a walnut that is found in the midbrain and generally acts as a way station for incoming sensory input. Robert Stickgold, Scientific American, 1 Oct. 2015 The good news is that even the midbrain can be trained and conditioned for constructive and creative, rather than destructive, responses. Rajni Bakshi, Quartz India, 1 Oct. 2019 The study found that the players had lower measures of fractional anisotropy in their right midbrains, which is a part of the brain stem. Fox News, 13 Aug. 2019 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'midbrain.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of midbrain

1864, in the meaning defined above

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The first known use of midbrain was in 1864

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Cite this Entry

“Midbrain.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/midbrain. Accessed 27 Jun. 2022.

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More Definitions for midbrain


mid·​brain | \ ˈmid-ˌbrān How to pronounce midbrain (audio) \

Medical Definition of midbrain

: the middle division of the three primary divisions of the developing vertebrate brain or the corresponding part of the adult brain that includes a ventral part containing the cerebral peduncles and a dorsal tectum containing the corpora quadrigemina and that surrounds the aqueduct of Sylvius connecting the third and fourth ventricles

called also mesencephalon

More from Merriam-Webster on midbrain

Britannica.com: Encyclopedia article about midbrain


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