Brain Health What Is the Hippocampus? By Kendra Cherry Kendra Cherry Facebook Twitter Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology. Learn about our editorial process Updated on October 18, 2022 Medically reviewed Verywell Mind articles are reviewed by board-certified physicians and mental healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Shaheen Lakhan, MD, PhD, FAAN Medically reviewed by Shaheen Lakhan, MD, PhD, FAAN Shaheen Lakhan, MD, PhD, is an award-winning physician-scientist and clinical development specialist. Learn about our Medical Review Board Print Sciepro / Getty Images Table of Contents View All Table of Contents Functions of the Hippocampus Risk Factors Impact of Damage Signs of Hippocampus Damage Impact Potential Pitfalls What Is the Hippocampus? The hippocampus is a small, curved formation located deep in the temporal lobe of the brain. As part of the limbic system, the hippocampus has three primary functions: forming new memories, learning, and emotions. It is susceptible to damage from injury, stress, and disease, including psychiatric and neurological conditions such as Alzheimer's, schizophrenia, and depression. The hippocampus plays a critical role in the formation, organization, and storage of new memories and in connecting certain sensations and emotions to these memories. It also plays an important part in the recall of emotional memories. Have you ever noticed how a particular scent might trigger a strong memory? It is the hippocampus that plays a role in this connection. 1:29 Click Play to Learn More About the Hippocampus This video has been medically reviewed by Huma Sheikh, MD. Functions of the Hippocampus Research has also found that different subregions of the hippocampus play important roles in certain types of memory. Spatial Memory The rear part of the hippocampus is involved in the processing of spatial memories. Studies of London cab drivers found that navigating complex mazes of big city streets is linked to the growth of the rear region of the hippocampus. Memory Consolidation The hippocampus also plays a role in consolidating memories during sleep. Studies published in 2004 suggest that greater hippocampal activity during sleep following some sort of training or learning experience leads to better memory of the material the following day. Memory Transfer Memories are not stored in the hippocampus for the long term. Instead, it is believed that the hippocampus acts as something of a shipping center, taking in information, registering it, and temporarily storing it before shipping it off to be filed and stored in long-term memory. Sleep is believed to play a critical role in this process. Location Because the brain is lateralized and symmetrical, you actually have two hippocampi. They are located just above each ear and about an inch-and-a-half inside your head. Risk Factors There are a few different factors that can affect the function of the hippocampus: Age: Age can also have a major impact on the functioning of the hippocampus. MRI scans of human brains have found that the human hippocampus shrinks by around 13% between the ages of 30 and 80. Those who experience such a loss may show significant declines in memory performance. Cell degeneration in the hippocampus has also been linked to the onset of Alzheimer’s disease.Stress: Stress can take a toll on the hippocampus, and may impair memory abilities. Social isolation: Loneliness and social isolation can have a variety of negative health effects, and research shows that they can also affect the functioning of the hippocampus.Lack of exercise: Lack of physical exercise may have detrimental effects on the brain, but research has found that exercise may help enhance hippocampal health and combat age-related cognitive decline.Depression: Research has shown that people with recurring, poorly treated depression experience decreased hippocampal size. The hippocampus may also play a role in contributing to the development of addictions. Because drugs and alcohol affect the brain's reward systems, the hippocampus creates memories of these satisfying experiences. It also may help form memories of environmental cues associated with substance use that can contribute to intense cravings when these cues are encountered again. Effects of Hippocampus Damage There are a number of things that can cause hippocampus damage, including traumatic brain injury, stroke, Alzheimer's disease, seizures, and ischemia. If the hippocampus is damaged by disease or injury, it can influence a person's memories as well as their ability to form new memories. Hippocampus damage can particularly affect spatial memory, or the ability to remember directions, locations, and orientations. Because the hippocampus plays such an important role in the formation of new memories, damage to this part of the brain can have a serious long-term impact on certain types of memory. Damage to the hippocampus has been observed upon post-mortem analysis of the brains of individuals with amnesia. Such damage is linked to problems with forming explicit memories such as names, dates, and events. The exact impact of damage can vary depending on which hippocampus has been affected. Research on mice suggests that damage to the left hippocampus affects the recall of verbal information, while damage to the right hippocampus results in problems with visual information. Signs of Hippocampus Damage Some of the signs of damage or injury to the hippocampus include: Changes in cognitive functioningMood dysfunctionProblems storing memoriesDifficulty recalling long-term memoriesSpatial disorientation and getting lost in familiar placesLosing or misplacing items oftenProblems following directionsProblems with decision-makingDifficulty carrying on conversations In addition to memory problems and other symptoms often linked to Alzheimer's disease, problems with the hippocampus are also linked to mental health conditions such as bipolar disorder, depression, and schizophrenia. How to Keep Your Hippocampus Healthy So what can you do to protect your hippocampus? Some tips that may help protect the health of your hippocampus include: Exercise regularly: Research suggests that exercise may help protect the hippocampus from the detrimental effects of aging. Manage your stress: Long-term stress can also have a negative impact on the hippocampus, so finding ways to manage your stress may help protect this part of your brain. Treat mental health conditions: Conditions such as PTSD and depression are associated with changes to the hippocampus. For example, some research suggests that stress associated with PTSD may also lead to damage to the hippocampus. People with PTSD have smaller hippocampi than people without PTSD. Protect your brain: Head trauma can damage the hippocampus, so it is important to utilize protective equipment, including helmets and seatbelts, in situations where an accident might result in a brain injury. 5 Surprising Ways That Stress Affects Your Brain History of the Hippocampus The term hippocampus is derived from the Greek word hippokampus (hippo meaning "horse" and kampos meaning "sea monster") because the structure resembles the shape of a sea horse. The structure was first described by the anatomist Julius Caesar Aranzi. Because the hippocampus has been known of and observed for centuries, it is one of the most studied areas of the brain. 18 Sources Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Tyng CM, Amin HU, Saad MNM, Malik AS. The influences of emotion on learning and memory. Front Psychol. 2017;8:1454. doi:10.3389/fpsyg.2017.01454 Maguire EA, Gadian DG, Johnsrude IS, et al. Navigation-related structural change in the hippocampi of taxi drivers. Proc Natl Acad Sci U S A. 2000;97(8):4398-4403. doi:10.1073/pnas.070039597 Peigneux P, Laureys S, Fuchs S, et al. Are Spatial Memories Strengthened in the Human Hippocampus During Slow Wave Sleep? Neuron. 2004;44(3):535-545. doi:10.1016/j.neuron.2004.10.007 Sherwood CC, Gordon AD, Allen JS, et al. Aging of the cerebral cortex differs between humans and chimpanzees. Proc Natl Acad Sci USA. 2011;108(32):13029-13034. doi:10.1073/pnas.1016709108 Anand KS, Dhikav V. Hippocampus in health and disease: An overview. Ann Indian Acad Neurol. 2012;15(4):239-246. doi:10.4103/0972-2327.104323 Kim EJ, Pellman B, Kim JJ. Stress effects on the hippocampus: a critical review. Learn Mem. 2015;22(9):411-6. doi:10.1101/lm.037291.114 Rivera DS, Lindsay CB, Oliva CA, Codocedo JF, Bozinovic F, Inestrosa NC. Effects of long-lasting social isolation and re-socialization on cognitive performance and brain activity: a longitudinal study in Octodon degus. Sci Rep. 2020;10(1):18315. doi:10.1038/s41598-020-75026-4 Wilckens KA, Stillman CM, Waiwood AM, et al. Exercise interventions preserve hippocampal volume: A meta‐analysis. Hippocampus. 2021;31(3):335-347. doi:10.1002/hipo.23292 ENIGMA-Major Depressive Disorder Working Group, Schmaal L, Veltman DJ, et al. Subcortical brain alterations in major depressive disorder: findings from the ENIGMA Major Depressive Disorder working group. Mol Psychiatry. 2016;21(6):806-812. doi:10.1038/mp.2015.69 Harvard Health Publishing. What is addiction? 2017. Shetty AK. Hippocampal injury-induced cognitive and mood dysfunction, altered neurogenesis, and epilepsy: Can early neural stem cell grafting intervention provide protection? Epilepsy Behav. 2014;38:117-24. doi:10.1016/j.yebeh.2013.12.001 Clark IA, Maguire EA. Remembering Preservation in Hippocampal Amnesia. Annu Rev Psychol. 2016;67:51-82. doi:10.1146/annurev-psych-122414-033739 Shipton OA, El-Gaby M, Apergis-Schoute J, et al. Left-right dissociation of hippocampal memory processes in mice. Proc Natl Acad Sci U S A. 2014;111(42):15238-15243. doi:10.1073/pnas.1405648111 Shetty AK. Hippocampal injury-induced cognitive and mood dysfunction, altered neurogenesis, and epilepsy: can early neural stem cell grafting intervention provide protection? Epilepsy Behav. 2014;38:117-24. doi:10.1016/j.yebeh.2013.12.001 DeCarolis NA, Eisch AJ. Hippocampal neurogenesis as a target for the treatment of mental illness: a critical evaluation. Neuropharmacology. 2010;58(6):884-93. doi:10.1016/j.neuropharm.2009.12.013 Duzel E, van Praag H, Sendtner M. Can physical exercise in old age improve memory and hippocampal function? Brain. 2016;139(3):662-673. doi:10.1093/brain/awv407 Kim EJ, Pellman B, Kim JJ. Stress effects on the hippocampus: A critical review. Learn Mem. 2015;22(9):411‐416. doi:10.1101/lm.037291.114 Logue MW, van Rooij SJH, Dennis EL, et al. Smaller Hippocampal Volume in Posttraumatic Stress Disorder: A Multisite ENIGMA-PGC Study: Subcortical Volumetry Results From Posttraumatic Stress Disorder Consortia. Biol Psychiatry. 2018;83(3):244-253. doi:10.1016/j.biopsych.2017.09.006 Additional Reading Myers DG. Exploring Psychology. 8th edition. New York: Worth Publishers; 2011. By Kendra Cherry Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology. See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit Speak to a Therapist Online Advertiser Disclosure × The offers that appear in this table are from partnerships from which Verywell Mind receives compensation.