hip·​po·​cam·​pus | \ ˌhi-pə-ˈkam-pəs How to pronounce hippocampus (audio) \
plural hippocampi\ ˌhi-​pə-​ˈkam-​ˌpī How to pronounce hippocampi (audio) , -​(ˌ)pē \

Definition of hippocampus

: a curved elongated ridge that extends over the floor of the descending horn of each lateral ventricle of the brain, that consists of gray matter covered on the ventricular surface with white matter, and that is involved in forming, storing, and processing memory

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Other Words from hippocampus

hippocampal \ ˌhi-​pə-​ˈkam-​pəl How to pronounce hippocampal (audio) \ adjective

Examples of hippocampus in a Sentence

Recent Examples on the Web Quietude, though, has been shown to promote the regeneration of brain cells in the hippocampus, which is key for learning, memory and emotion. Pete Mcbride, Smithsonian Magazine, "The Last Quiet Places," 18 Sep. 2020 Scientists trained subjects to exercise control over a single neuron, linked the hippocampus to regret, and concluded that humans smell in stereo. Rafil Kroll-zaidi, Harper's Magazine, "Findings," 18 Aug. 2020 The hippocampus generated a representation of the left-turning choice during one cycle, then switched to the right-turning choice for the next one. Quanta Magazine, "In Brain Waves, Scientists See Neurons Juggle Possible Futures," 24 Feb. 2020 These findings suggest that the hippocampus generates longer ripples during memory-intensive activities, and that these longer-duration signals improve performance. Simon Makin, Scientific American, "Better Memory Through Electrical Brain Ripples," 14 June 2019 In studies using animals (five rats in the initial one), Dr. McEwen and his colleagues demonstrated that toxic stress atrophied neurons near the hippocampus, the brain’s memory and learning center. Randi Hutter Epstein, BostonGlobe.com, "Bruce McEwen, 81, found stress can alter the brain," 12 Feb. 2020 Scientists aren’t sure exactly why that is, but one theory is that high levels of the stress hormone cortisol, which can occur with depression, is toxic to the hippocampus, a part of the brain that is critical for storing long-term memories. Andrea Petersen, New York Times, "New Therapies Help Patients With Dementia Cope With Depression," 8 Dec. 2019 Spurred by the realization that these cells interfere with the hippocampus, a brain region needed to consolidate memories, the team decided to conduct a series of tests. Meilan Solly, Smithsonian, "Dreaming May Help the Brain Forget Excess Memories, a Study of Mice Shows," 21 Sep. 2019 Activity in the hippocampus tracked the angle of the characters to the participant. Matthew Schafer, Scientific American, "In Search of the Brain’s Social Road Maps," 1 Feb. 2020

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

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First Known Use of hippocampus

1695, in the meaning defined above

History and Etymology for hippocampus

New Latin, from Greek hippokampos seahorse, from hippos horse + kampos sea monster — more at equine

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Time Traveler for hippocampus

Time Traveler

The first known use of hippocampus was in 1695

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Statistics for hippocampus

Last Updated

23 Sep 2020

Cite this Entry

“Hippocampus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hippocampus. Accessed 30 Sep. 2020.

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More Definitions for hippocampus


hip·​po·​cam·​pus | \ ˌhip-ə-ˈkam-pəs How to pronounce hippocampus (audio) \
plural hippocampi\ -​ˌpī How to pronounce hippocampi (audio) , -​(ˌ)pē How to pronounce hippocampi (audio) \

Medical Definition of hippocampus

: a curved elongated ridge that is an important part of the limbic system, extends over the floor of the descending horn of each lateral ventricle of the brain, consists of gray matter covered on the ventricular surface with white matter, and is involved in forming, storing, and processing memory — see pes hippocampi

More from Merriam-Webster on hippocampus

Nglish: Translation of hippocampus for Spanish Speakers

Britannica.com: Encyclopedia article about hippocampus

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