Memories and Mental Health

There has been a lot of research on how the memories we make in our life have an impact on our mental health. The severity or amount of times that certain memories are activated in the brain can affect someone’s short-term and/or long-term emotional and mental state. This idea holds true for many kinds of memories, including positive and negative ones. With negative memories, in particular, having them stored and recalled in the brain a number of times can lead to forming or worsening of certain mental health conditions, including phobias, anxiety disorders, and PTSD (post-traumatic stress disorder). To improve current methods of mediating these disorders based on traumatic memories, and possibly find new methods to do so, it is crucial to learn more about the mechanism of how traumatic/negative memories affect the brain and how this effect can be reduced.

Fearful memories are usually encoded to help us identify a threat to survive, but if those memories are no longer needed and continue to be recalled even when no threat is present, it can lead to the development of certain disorders such as PTSD. To learn about the mechanisms that explain how fearful memories are kept in our brain or how they are suppressed, a group of researchers from NIH’s National Institute on Alcohol Abuse and Alcoholism and Institute for Biomedical Research tried to see what cells in the brain are responsible for suppressing or preserving negative memories and how they interact. They used in vivo calcium imaging in mice and tracked cell activity in the brain after putting the mice through fear conditioning. The researchers found that groups of neurons in the amygdala called intercalated cells compete with each other to either repress or preserve the fear-based memory and saw that after the unconditioned stimulus was taken away (a shock administered to the mice’s feet), the mice also showed less of a fearful response (Hagihara et. al., 2021). The results of this study gave more insight into the neural mechanisms that underlie the sustentation and/or extinction of fear in the brain.

  Currently, there are various methods people use to mediate the impact that negative memories have on their mental health, such as counseling or taking medication, but recent studies have introduced a new possible method to minimize negative memories, particularly those based on fear. A recent study led by Dr. Grella and her team introduced a way that negative fear-based memories can be disrupted by using optogenetics. During the reconsolidation of fear-based memories in mice after fear conditioning, positive memories were reactivated in the hippocampus. The results were that reactivating positive memories actually helped in disrupting the fear and reducing the impact they had on the mice (Grella et. al., 2021). Although the idea of using the same method on humans appears difficult, studies such as this show that in the near future, we may have more options to help people who suffer from mental health conditions such as PTSD.

Works Cited: 

Hagihara, K. M., Bukalo, O., Zeller, M., Aksoy-Aksel, A., Karalis, N., Limoges, A., Rigg, T., Campbell, T., Mendez, A., Weinholtz, C., Mahn, M., Zweifel, L. S., Palmiter, R. D., Ehrlich, I., Lüthi, A., & Holmes, A. (2021). Intercalated amygdala clusters orchestrate a switch in Fear State. Nature, 594(7863), 403–407. https://doi.org/10.1038/s41586-021-03593-1 

Grella, S. L., Fortin, A. H., Ruesch, E., Bladon, J. H., Reynolds, L. F., Gross, A., Shpokayte, M., Cincotta, C., Zaki, Y., & Ramirez, S. (2022). Reactivating hippocampal-mediated memories during reconsolidation to disrupt fear. Nature Communications, 13(1). https://doi.org/10.1038/s41467-022-32246-8

Sleep, Mental Health, and the Gut Microbiome

Within each of our bodies, thousands of species of microorganisms— bacteria, fungi, parasites, and viruses—coinhabit our organs, particularly abundant in the small and large intestines. This microscopic community of organisms, known as the gut microbiome, functions as a support system for the body, heavily contributing to the health of an individual and playing a crucial role in various physiological processes. One such process is sleep, which can be understood by looking into Dr. Martha Vitaterna’s research studying the link between the gut microbiome and the regulation of sleep. 

Dr. Vitaterna’s paper, “A Prebiotic Diet Alters the Fecal Microbiome and Improves Sleep in Response to Sleep Disruption in Rats”, investigates how administering a prebiotic diet affects recovery after sleep disruption in rodents. This prebiotic diet stimulates growth of beneficial bacteria in the gut microbiome, and this study demonstrates that its effects include a heightened resilience to circadian disruption. Mice on this prebiotic diet exhibit increased sleep during the sleep disruption protocol and longer bouts of sleep during the sleep recovery period. This research highlights the prospect of therapies that target the gut microbiome, and circadian disruption is just one among many physiological complications that could be treated through the gut microbiome. 

On December 12, Medical News Today published an article delving into the relationship between the gut microbiome and depression. According to the World Health Organization, depression is a leading cause of disability worldwide. Though the causes of depression are not fully understood, scientists agree that multiple types of environmental and biological factors contribute to the development of the disease. One likely contributor is the levels of neurotransmitters in the brain. The MNT article “Do gut bacteria play a role in depression?” discusses recent research that found a link between the gut microbiome and the production of the neurotransmitters serotonin and glutamate, which are thought to influence depression. A study involving 1,133 human participants found an association between symptoms of depression and 13 types of gut bacteria. This association could be the discovery of a potential biomarker for depression, which would improve the accuracy of diagnosing depression in patients, and it could even lead to potential treatments of depression. 

On the clinical implications of this research, Dr. Najaf Amin was quoted, “Since gut microbiome is primarily determined by the lifestyle factors, diet in particular, once causality is established, the therapy would be as simple as modification of diet or the use of probiotics.” If a prebiotic diet can effectively improve sleep impediments in rodents as shown by Dr. Vitaterna’s research, then perhaps it is possible that such a diet could help alleviate symptoms of depression in humans. 

Works Cited 

Bowers, Samuel J., et al. “A Prebiotic Diet Alters the Fecal Microbiome and Improves Sleep 

in Response to Sleep Disruption in Rats.” Frontiers in Neuroscience, vol. 16, 2022,    https://doi.org/10.3389/fnins.2022.889211. 

Cross, Paul Ian. “Do Gut Bacteria Play a Role in Depression?” Medical News Today, 12 Dec. 

2022,  https://www.medicalnewstoday.com/articles/do-gut-bacteria-play-a-role-in-depression. Accessed 14 Dec. 2022. 

Waking Up on the (B)right Side of the Bed

    Moving to a new place can be exciting however, it can also come with unforeseen challenges as well. When I moved from Rogers Park to live in a more central area of Chicago I knew that I would have to wake up earlier in order to be on time for my commute. This sounded incredibly easy to me because it seems like one can simply go to sleep earlier and feel like a fresh spring chicken when their alarm sounds. When I was met with the opposite feeling in the morning this was an incredible surprise. For weeks I could not understand exactly why I was so fatigued as if I barely slept throughout the night until I realized that it was the result of waking up in the darkness. 

    For years, Seasonal Depression / Seasonal Affective Disorder (SAD) has been extremely talked about on social media with influencers providing the masses with the latest tips and tricks to keep yourself motivated through the gloomy months. The main draw of SAD is the desire to stay in bed all day because of the gloomy winter weather. This disorder can be treated with light therapy according to the Mayo Clinic, “It's thought that this type of light may cause a chemical change in the brain that lifts your mood and eases other symptoms of SAD, such as being tired most of the time and sleeping too much”(2022). This is exactly where I found myself at the beginning of the school year before I decided to take action. First, knowing that I was getting quality sleep was important before I threw money at a device to fix all of my problems. Getting a sunrise alarm clock has brought the best of both worlds to my morning routine as well as quality of sleep. This alarm clock has a light sequence that mimics that of an actual sunrise. The gradual increase of light as well as the alarm sound chosen (mine is chirping birds) makes you really feel like you are waking up alongside the sun. This consistent part of my morning routine is crucial in my sleep and actually feeling rejuvenated.

    Dr Allada and colleagues were able to show how different aspects that influence your sleep and wake cycles affect your quality of sleep along with functioning during wake times. While their study relied heavily on altering the sleep schedules of fruit flies and observing the effects on their “body clocks” this is something we can apply to humans. This model organism was able to represent the neurological effects of different disruptions in sleep and in turn, how this affects the organism throughout daily function. They were able to find that different neurons have different reactions to varied stimuli in the morning as well as at night. This is representative of the importance of sunlight in the morning for us humans and how it allows our brains to power up. When we see light we know that it is time for action and productivity where when we are exposed to the opposite we are more sluggish. Sunlight lamps or alarms can reinforce this neurological morning activity through the seasons that may not naturally offer as much. 

    While sleep may be seen as a luxury lately in our culture, it is the first step of a healthy lifestyle. Being able to recharge your body can lead it to do amazing things and make a huge difference in our day to day. It’s never too late to take control of your sleep and bring a little light into your life. 

Resources

Mayo Clinic (2022) Seasonal Affective Disorder Treatment: Choosing a Light Box. Mayo Foundation for Medical Education and Research https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/in-depth/seasonal-affective-disorder-treatment/art-20048298. 

Tomas Andreani, Clark Rosensweig, Shiju Sisobhan, Emmanuel Ogunlana, William Kath, Ravi Allada (2022) Circadian programming of the ellipsoid body sleep homeostat in Drosophila eLife 11:e74327 https://doi.org/10.7554/eLife.74327

Teenagers Sleeping In Late and Getting Up Early: Problematic

We have all had those days in high school when we pulled all-nighters, slept in till noon, or stayed up on a school night to play video games or just have fun with friends. That's just the high school experience right? That scenario may have been a normal occurrence to us all, however, there were many repercussions going unnoticed due to those choices. Sleep deprivation in adolescents is found to be very common internationally, up to 73% of high schoolers report getting less than 8 hours of sleep, yet those years are the most crucial for growth and brain development. A teenager should be getting an average of 8-10 hours of sleep per day, however, the reality of it is that most teenagers only get an average of 7 - 7.25 hours of sleep each day (Paruthi 1560). The serious repercussions of sleep deprivation in teenagers are mainly found to affect focus and learning and cause depression and mood changes when prolonged. Schools have looked at some ways to help adolescents get more quality sleep by pushing back some of their start times and found that students are much more active and aware with just an hour or two hours delay. Unfortunately, not enough research has been done on a teenager's schedule to determine why there is such a prevalence of a lack of quality sleep. 

An abundance of previous research has been done looking at light exposure before sleep and concludes that blue light exposure is detrimental to the sleep onset of adolescent teens. A study was done by Dr. Ieva Misiunaite et al., looking at the effects of sleep deprivation on teenagers when they stay up late during school nights and sleep in on the weekends. In their paper titled “Circadian Phase Advances in Response to Weekend Morning Light in Adolescents With Short Sleep and Late Bedtimes on School Nights”, they found that the circadian rhythms of these teenagers tend to have a phase advance meaning they naturally go to sleep and wake up earlier than they used to. This causes adolescents to fall asleep in class or nap after school much more than they should (Misiunaite 99). They concluded this by having 41 adolescents (19 of these being males) do a Sleep Habit Study and a pre-study sleep log. After the surveys, they had the participants sleep at home for 15 days with their normal sleep schedule. Then they had them go through a constant routine before exposing them to bright lights in the morning on the weekend. The researchers looked at how the amount of light shone onto the teenagers on the weekend affected what time they went to sleep. Through this, they concluded that bright lights in the morning would stimulate waking up late which in turn made the teenagers go to bed early to fix their sleep schedule (Misiunaite 99). This means that the cost of staying up late on school days, averaging about 5 hours of sleep in the study population, is reflected on the weekends when the bright lights cause an advance in sleep onset. 

This conclusion ties in with the conclusion found in Dr. Tomas Andreani et al., a research paper titled “Circadian programming of the ellipsoid body sleep homeostat in Drosophila” which proves that sleep is dependent on the molecular proteins clock (clk) and period (per). By manipulating sleep by sleep-depriving drosophila flies they found that more sleep delay caused increased sleep rebound or increased time sleeping. Specifically, the neurons that mediate morning and evening sleep rebound, glutamatergic ND1p circadian neurons, are what also regulate body sleep homeostasis of the r5 ellipsoid. Overall in this study, they concluded that the necessary neurons, in this case, the r5 ellipsoid neurons, show increased levels of gene expression in activity/wake-dependent genes in the morning rather than the evening (Andreani 7). 

These research findings are a major stepping stone for Dr. Misiunaite and their investigation into the reason behind a high schooler's lack of quality sleep as the light manipulations are done caused the clock and period proteins to advance in deterioration. These findings can help teenagers get the quality sleep they need to grow and develop into adulthood. Implicating a better schedule both at school and at home for teens would be vital for their sleep health, especially when limiting light intake before bed and as they are waking up. Just this small change can be the small boost they need to succeed in their high school experience and onward. 

Citations:

Misiunaite, Eastman, C. I., & Crowley, S. J. (2020). Circadian Phase Advances in Response to Weekend Morning Light in Adolescents With Short Sleep and Late Bedtimes on School Nights. Frontiers in Neuroscience, 14, 99–99. https://doi.org/10.3389/fnins.2020.00099

Andreani, Rosensweig, C., Sisobhan, S., Ogunlana, E., Kath, W., & Allada, R. (2022). Circadian programming of the ellipsoid body sleep homeostat in Drosophila. eLife, 11. https://doi.org/10.7554/eLife.74327

Paruthi S, Brooks LJ, D’Ambrosio C, et al. Consensus statement of the American Academy of Sleep Medicine on the recommended amount of sleep for healthy children: methodology and discussion. J Clin Sleep Med 2016;12:1549–61.

A Day in the Life: College Student Edition

 

We’ve all heard someone once in our life tells us to make sure we get our rest or that sleep is important to us. Have you ever stopped to think of the science behind this? Why is sleep important to us? What does sleep do to our brain? Sleep is important to many of our brain functions like how our neurons communicate with one another through synapses. Even while we’re asleep, our brains are continuously staying active. In fact, “recent findings suggest that sleep plays a housekeeping role that removes toxins in your brain that build up while you’re awake” (NIH, 2022). One such toxin is beta-amyloid, a waste product associated with Alzheimer’s disease. Sleep is also known to improve memory recall, regulate metabolism and reduce mental fatigue (Eugene, 2015).  

Today, sleep is something a lot of people tend to struggle with. Lack of sleep or sleep deprivation has become a common issue, especially in college students. With stress in the lead for reasons for difficulties with academic performance, sleep problems are a close second (Emerson, 2022). According to this article, more than 70% of college students reported that they get less than the normal 8 hours of sleep. This lack of sleep follows alcohol use, caffeine and energy dependence and stimulant dependence which in return causes more problems along the lines of health. Sleep deprivation weakens the immune system, has a higher risk for diabetes, high blood pressure, and heart disease, and it can affect learning. 

In his article "Circadian programming of the ellipsoid body sleep homeostat in Drosophila", Ravi Allada and his colleagues researched on how homeostatic and circadian processes come together to explain sleep and wake patterns in fruit flies. Their experiment consisted of taking sleep away from Drosophila during specific times of the day and the results showed a greater bounce back in the morning than in the evening. With these results, they found that the lack of sleep in the morning increases calcium levels and gene expression whereas this isn't the case in the evening. In other words, waking up earlier in the day rather than staying awake late at night, results in better health (Allada, 2022).  

Bringing the two articles together, we can take the information gained from Allada et. al's article and apply it to humans as well. Going back to what I mentioned earlier about college students, getting enough sleep is critical to our health so it might be a good thing for our nights to consist of sleeping but mornings for productivity. In this way, we not only get any toxins cleared up through our sleep, but we get critical vitamins for our body by being up early in the morning. A takeaway we can get from these articles is to prioritize our sleep. A lot of us want to enjoy college while we’re there but our health should be a top priority. 

 

 

 

 

Resources:

U.S. Department of Health and Human Services. (n.d.). Brain basics: Understanding sleep. National Institute of Neurological Disorders and Stroke. Retrieved December 14, 2022, from https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep 

 

 
 

Eugene, A. R., & Masiak, J. (2015, March). The neuroprotective aspects of sleep. MEDtube science. Retrieved December 14, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651462/ 

 

 

About Joe Emerson Joe Emerson spent 30 years as a magazine and newspaper reporter. (n.d.). The importance of sleep for college students. Office of Admissions. Retrieved December 14, 2022, from https://admissions.usf.edu/blog/the-importance-of-sleep-for-college-students#:~:text=More%20than%2070%20percent%20of,negatively%20affects%20their%20academic%20performance. 

 

 

Andreani, T., Rosensweig, C., Sisobhan, S., Ogunlana, E., Kath, W., & Allada, R. (2022, June 23). Circadian programming of the ellipsoid body sleep homeostat in drosophila. eLife. Retrieved December 14, 2022, from https://elifesciences.org/articles/74327