The hippocampus is a word taken from Greek, meaning “seahorse” because of its shape. It describes a major component of the brain in humans and other vertebrates. Humans and other mammals have two hippocampi, one on each side of the brain. The hippocampus plays an important part in the limbic system, while having a primary role in directing and organizing information from short-term to long-term memory as well as spatial memory that involves navigation.

The hippocampus is located in the most inner folds of the bottom of the temporal lobe of the brain. The hippocampus was first described in 1587 by Julius Caesar Arantius which led scientists to help understand how human memory works.

Functions of the Hippocampus

The two main functions of the hippocampus involve learning and memory. It also is part of the limbic system which manages feelings, emotions and reactions to stress.

The limbic system also involves the hypothalamus and amygdala, which control the endocrine system to regulate the “fight or flight “ response during stressful events.

Memory

The hippocampus coordinates humans ability to process memories in two ways: declarative or episodic and spatially.

Declarative or episodic memories have to do with those that are related to specific events or involve facts. An example would be how one learns a poem or can retrieve information from an article they’ve read.

Spatial memories have to do with finding or remembering how to get somewhere when you drive or navigate your way through your property or city.

Short-term memories are converted to long-term ones in the hippocampus and then stored in other areas of the brain for future use.

Damage and Diseases Involving the Hippocampus

Alzheimer’s disease or a brain injury (TBI) can have harmful effects in one or both areas of the hippocampus which can have an impact on ones ability to remember certain details. Since the long-term memory is stored in another brain region the experience of an accident can result in someone not remembering the event which just happened but still remember something that happened a long time ago.

Other types of damage that involve the hippocampus could be transient global amnesia, which is a specific form of memory loss which comes on suddenly and then can go away in a short amount of time.

Transient global amnesia may be a result from damage that occurs in the hippocampus region of the brain.

Those with hippocampus deficits can find it more difficult to navigate new surroundings but will still remember the neighborhood they grew up in.

There are also studies which show how the size of the hippocampus can effect its ability to function properly. For instance, according to a 2021 meta-analysis and a 2017 study indicate that a smaller hippocampus volume correlates to conditions like schizophrenia, PTSD and severe depression.

Alzheimer’s Disease can affect the hippocampus in its early stages when forgetfulness starts to become noticeable. As the disease progresses, the hippocampus can reduce in size resulting in a greater loss of memory and function.

Long-term stress and depression has been associated with having negative consequence that may lead to a smaller hippocampus over time. Scientists are not certain if the stress or depression leads to the lack of volume in the hippocampus or if the smaller hippocampus is a cause of the conditions.

Cushing’s syndrome is a condition where the body over produces the stress hormone cortisol over long periods of time due to a stressful life. One of the symptoms of Cushing’s syndrome is a smaller hippocampus. However, doctors are unsure if having a smaller volume hippocampus is an underlying cause or a result of the condition.

Epilepsy has been believed to make changes in the hippocampus region of the brain. The relationship in how the hippocampus makes neurons is different than in normal healthy populations. But doctors are unsure if these differences are a result or part of the cause of the condition.

Early Indicators

It should be stated that a reduction in functional memory is a natural result of aging. Mild forgetfulness is quite normal but there are other signs that will point to hippocampus damage that will result in an inability to create new memories and remember old ones.

The National Institute on Aging says some indicators of hippocampus damage may include:

• poor decision making

• showing signs of lack of personal care

• ability to hold a coherent conversation

• getting lost in normal or familiar surroundings

• difficulty understanding directions

• repeatedly asking the same questions

Hippocampus Health

Brain health in general begins with diet and activity. Protective measures may include:

• adhering to a balanced diet containing fruits and vegetables, whole grains, nuts and seeds.

• staying on top of any chronic health conditions such as: diabetes, high blood pressure and cholesterol levels.

• getting enough physical exercise

• managing daily stress levels

• getting enough sleep

• quit smoking and alcohol

• maintaining a healthy body weight and BMI

Risk Factors

The most common risk factor in brain health and cognition in general has to do with reducing stress in ones life. Hippocampus damage as a result of dementia increases as we age. Risk factors include:

• older age

• genetics

• social isolation

• lack of physical exercise

• being less education

• severe depression that goes untreated

  Exercise and Hippocampus Health

A review of research done in 2021, indicates how exercise can make positive affects on the aging population who’s most at risk in developing dementia. The authors of the study concluded that exercise and an increase of physical activity, especially in older people may preserve the hippocampus volume. The mechanisms in play are not conclusive, but the science community believes that exercise brings greater volumes of blood supply and oxygen improving circulation to the brain and hippocampus areas.

A 2021 review published in Frontiers in Human Neuroscience, says exercise may help the brain’s ability to remove the amyloid plaque and generate new nerve cells which is known to be a problem for those with Alzheimer’s disease.

Science is always learning more about the involvement of hippocampus in our day to day activities. In fact, a 2019 study which involved brain MRI scans showed low level activity in the hippocampus that may signal other areas of the brain is active in giving details to help identify ones environment which could help predict future events.

This means that the hippocampus could be involved not only in the formation and storage of short and long-term memories but also integrated in the functional connectivity having to do with sensations like, vision, hearing and touch. It appears that the hippocampus is more integrated with brain structures having to do with learning than what was previously believed.

The hippocampus is quite a special region of the human brain with all its capabilities dealing with memory formation and learning. It is the hippocampus that gives us our ability to remember facts about our world and environment from the most broad expansive concepts to the most infinitely detailed bits of information. Taking care of our brain through proper diet, exercise and a reduction of stress will give the best chance for a healthy and productive life as we age.

-A Balanced Brain is a Better Brain-