The strange name of that all-important little part of our brain comes from the Greek words for "horse" and "monster." Hippocampus roughly translates back to our word "seahorse" because of its shape. We have two hippocampi, one resting on either side of the brain, a few inches above the ears. So what is the purpose of this small but vital part of the brain known as the hippocampus?
The hippocampus is of vital importance in the brain's limbic system, which controls our emotions and reactions. The hippocampus helps people process and recall two types of memory: spatial relationship memories and declarative memories. It also transforms our short-term memories into long-term ones.
The hippocampus is one of the most explored areas of the brain, with scientists knowing about this structure for more than 400 years. This research gave us tremendous insight into how people learn and remember and what the brain does with the newly created memories.
The Functions Of The Hippocampus
Each hemisphere of the brain comprises four lobes; frontal, parietal, temporal, and occipital. The temporal lobe is responsible for language comprehension, memory, hearing, and the sequencing and organization of information. (1)
The hippocampus is a section of the brain seated deep inside the temporal lobes of each cerebral cortex. It's an essential part of the brain's limbic system, which is an area that controls learning, memory, emotions, and motivations.
Previously, people falsely believed that the hippocampus was only involved in receiving information directly from the olfactory bulb. But today, people are still fascinated with the hippocampus' memory of smells. Have you ever smelled an odor that took you straight back to an event in your memory?
Hippocampus And Memory Formation
Memory is a complicated process that involves three stages: encoding, or the selection of important information, storing it, and recalling the memories.
The hippocampus organizes and stores new memories, especially the declarative type. It also strengthens memories by connecting them to sensations and emotions. Declarative memories are those regarding events and facts. (3)
The hippocampus is connected to a neighboring brain structure called the amygdala, which controls emotions, especially fear. The amygdala and hippocampus often work together to strengthen new memories by associating emotions with them. If a recent memory has a tad of fear attached to it, the person will remember it more easily. (2)
Evidence from a famous 1953 case study shows that removing the hippocampus allowed a patient nicknamed HM to retain his cognitive abilities. Still, he lost the ability to make new memories. This condition is called retrograde amnesia. This side effect of the surgery strengthened the theory that the hippocampus is crucial to making new memories.
The hippocampus also plays a crucial role in spatial navigation. The back end of the hippocampus is responsible for our ability to process spatial memories. This allows us to encode our environments to remember where everything is. Our brain stores our spatial relationship memories in the right hippocampus.
Our spatial memories contain cognitive maps with information regarding relative locations within particular environments. Using mental maps enables us to code, decode, store, or recall information about the current place that we can use when navigating familiar areas. Cognitive maps help us navigate a space with what we already know about the place. (4)
Taxi drivers are good examples. We would expect that they have detailed and extensive cognitive maps to prevent them from getting lost. A study done with 16 taxi drivers in 2000 revealed that they had more grey matter at the back of their hippocampi than a control group. This proves that the hippocampus is essential in short-term memory and spatial navigation.
Hippocampus Transfers Long-Term Memories
Although the hippocampus is central to memory, it does not store the long-term memories there. Instead, scientists believe that it acts as a transfer center for them. The hippocampus takes in the memory information, registers it, and holds on to it briefly before sending it to the long-term memory stores. (5)
Scientists believe that sleep plays a central role in transferring long-term memories. Information floats around the hippocampus area while neurons encode the data through the process of long-term potentiation. Long-term potentiation is necessary for memory storage. (2)
When long-term potentiation happens in the hippocampus, the strongest circulating data returns to the part of the brain where it came from to transform the short-term memo into long-term ones.
While a person sleeps, brain activity helps the brain assimilate and store information, improving your memory. Lack of sleep lessens the brain's ability to consolidate new information. If you skimp on sleep, you will impair your memory. (10)
Hippocampus Influences Behavior
The hippocampus influences goal-directed and flexible behavior. We need a healthy hippocampus to form and reconstruct relational memory. We need this to make connections between arbitrary events or objects. A damaged hippocampus can prevent somebody from using flexible information correctly, leading to inappropriate or maladaptive behavior. (4)
In addition, evidence shows that hippocampus damage can cause hyperactivity in the patient. Literature also proves that it can reduce the ability of a person to inhibit a previously learned response.
What Happens When The Hippocampus Gets Damaged?
If a person suffers damage to their hippocampus or experiences hippocampus dysfunction, they may display some of the following symptoms: (2)
- Mild to severe memory loss.
- Disorientation
- Unable to form new memories while long-term memories remain intact.
- Unable to remember directions
- Unable to find places that should be familiar.
- Inability to remember words.
- Unable to memorize new information.
Diseases And Disorders That Impair Hippocampus Function
The hippocampus is a sensitive and delicate part of the brain. Certain conditions, including high levels of stress, can impair its functioning.
Alzheimer's Disease Can Affect The Hippocampus
The hippocampus will be one of the initial areas of the brain to be affected by Alzheimer's Disease. Early symptoms of this disease are when a person starts losing their short-term memory and struggles to follow directions. As the condition gathers momentum, the hippocampus shrinks, and it becomes more challenging to live a normal daily life.
Epilepsy And The Hippocampus
Scientists estimate that 50-75% of people who have epilepsy have damaged hippocampi. Still, doctors are uncertain whether epilepsy causes damage to the hippocampus or the damaged hippocampus causes epilepsy. (7) Experts believe that many of these patients also struggle with short-term memory loss.
Depression And The Hippocampus
Research shows that people with depression have smaller hippocampi. The hippocampus can shrink by up to 20% in some cases. Evidence reveals that the hippocampus of people with severe depression can be 10% smaller than those without depression. Hippocampus atrophy also correlates with the length of time a person has struggled with depression.
Schizophrenia, Bipolar Disorder, And Hippocampus
People with Schizophrenia and other cognitive disorders often also present with hippocampal volume reduction.
Ageing Can Weaken Hippocampus Function
Sometimes the hippocampus functioning in older adults weakens due to age, and they begin to struggle with short-term memory, etc.
Transient Global Amnesia
Transient Global Amnesia is a sudden-onset memory loss where most of the short-term memory is lost. It is usually temporary. Various conditions could cause this dramatic amnesia, such as epilepsy, ischemia, migraines, and cerebral venous blood flow disturbances. (6)
Post-Traumatic Stress Disorder Affects The Hippocampus
PTSD is closely linked to the person's memory and experience of a stressful event. People living with PTSD could have forgotten some of the traumatic experiences or that their memories are with them all the time.
Stress triggers the body to release cortisol, our "flight or fight" hormone that indicates that we are in danger. Too much cortisol is detrimental to the health of the hippocampus.
How Stress Impacts The Hippocampus
Stress makes the hippocampus area vulnerable to hormones that can cause abnormal connections in the brain and change a person's behavior. High cortisol levels cause the body to secrete inflammatory chemicals, resulting in decreased serotonin production and increased glutamate production. These chemicals contribute to brain cell degradation. (7)
How To Improve Your Hippocampus Function
If you're losing your memory or struggling with some of the conditions associated with hippocampus decline, we can improve its functioning. Making changes in our lifestyles will help prevent memory loss and cell degradation.
Exercise To Improve Hippocampus Function
According to the Alzheimer's Research and Prevention Society, we can reduce our chances of getting Alzheimer's by 50% if we exercise regularly. Any exercise is beneficial to the brain, but aerobic activities, such as running, walking, cycling, swimming, dancing, and boxing, are especially effective in preventing the disease.
Exercising releases powerful endorphins into the system, which helps to lift heavy moods and fights depression and stress.
Change Your Diet To Improve Your Hippocampus Function
Diet plays a massive role in improving your memory. That means you have to get rid of fast food and substitute it with healthier options.
Fish, especially the oily type, is excellent for brain function. The Omega-3 fatty acids improve brain signaling and cellular structure. Salmon, mackerel, and sardines are rich in Omega-3.
Blueberries are good for the body and brain. They help prevent DNA damage and fight against disease-causing free radicals. Blueberries are also great for improving memory.
Coffee has some great benefits for the brain. It bumps up our serotonin level, which improves our mood. The caffeine helps us focus and blocks the chemical adenosine that causes drowsiness. Coffee also contains antioxidants and helps improve your memory. It's a good one all around!
Dark chocolate is rich in antioxidants, which fight free radicals. It also releases dopamine into your system, which aids learning and memory retention.
Stimulate Your Brain With Mental Activities
By the time we get older, our brain contains millions of neural pathways, which makes it easier to solve problems that you have solved before. It's important to keep your brain on point by creating as many new neural pathways as possible.
Crossword puzzles build up plasticity in the brain and make new connections between nerve cells. At the same time, you will be enjoying yourself, which will help to reduce stress.
Take a different route home. Driving the same route every day shifts your brain to autopilot mode. Taking another way home will stimulate the cortex to process the new information and wake the hippocampus up.
There are thousands of brain-training apps and online games designed to stimulate your brain. They work on your problem-solving abilities, memory, attention span, and processing speed.
Getting Rid Of The Smartphone Improves Hippocampus Function
Phones can be addictive, but we also rely so heavily on them for remembering and researching everything and allow our brains to become lazy. Phones are also hugely distracting. Although phones may not cause cognitive decline, spending more time thinking for ourselves and using our brains will undoubtedly help prevent it. (9)
Getting Enough Sleep Is Essential For The Hippocampus
Research shows that Chronic Sleep Deprivation is connected to various health issues, such as heart disease, high blood pressure, obesity, depression, diabetes, and Alzheimer's disease. Lack of sleep also aids memory loss. Adults require 7 hours of sleep per night or more for a happy body and brain.
Meditation Improves Well-being
Spending time alone in a quiet space is good for the soul. Meditation can transform how your brain sees fear, which is usually related to stress and anxiety. Meditating for fifteen minutes a day can positively influence your general well-being.
It relieves the symptoms of stress and anxiety and gives you more capacity to empathize and be more compassionate towards others. When we decrease our stress levels, our hippocampus functions better. We make better choices, and our brains respond accordingly.
Conclusion
The hippocampus is a vital part of our brain responsible for our memory processes, which we might underestimate sometimes. The hippocampus is involved in our ability to create new memories, store them, and help transform them into long-term memories before sending them off to their new homes. The hippocampus also facilitates our spatial navigation and influences our behavior.
Several disorders and diseases can negatively impact the functioning of the hippocampus, which could lead to memory loss. Still, there are several actions we can take to ensure our well-being and prevent hippocampus decline. Memories and mental health are crucial for our quality of life, so we should make better lifestyle choices to this end. Don't forget to remember all these pointers!
References
- https://www.medicalnewstoday.com/articles/313295
- https://www.news-medical.net/health/Hippocampus-Functions.aspx
- https://www.masterclass.com/articles/hippocampus-explained
- https://www.simplypsychology.org/hippocampus.html
- https://en.wikipedia.org/wiki/Hippocampus
- https://www.verywellmind.com/what-is-the-hippocampus-2795231
- https://www.growthengineering.co.uk/train-your-hippocampus-function/
- https://achs.edu/blog/2015/06/08/memories-matter-6-easy-tips-for-a-healthy-brain/
- https://mayfieldclinic.com/pe-anatbrain.htm
- https://eachnight.com/sleep/sleep-and-memory/#:~:text=Lack%20of%20sleep%20affects%20your,get%20compromised%2C%20impairing%20your%20memory
