What happens when we sleep?

In 2017, an article was published in the New York Times titled, “The Purpose of Sleep? To Forget, Scientists Say”. In this article, Carl Zimmer summarizes the work of multiple scientists and their findings on the purpose of sleep. He presented previous theories on why humans sleep, including to save energy, hide from predators, and clear away the brain’s cellular waste. He then discussed the work of Giulio Tononi and Chiara Cirelli, biologists from the University of Wisconsin-Madison. These two scientists proposed that while sleeping, human brains prune synapses to get rid of the noise and only keep what is important. While these two researchers found indirect evidence to support their hypothesis, they were unable to find a direct link between sleep and synapse pruning, what they called the synaptic homeostasis hypothesis.

It was Graham H. Diering, a postdoctoral researcher at Johns Hopkins University, who was able to find some more definitive evidence. He, along with his team, studied the synaptic homeostasis hypothesis by studying proteins in the brains of mice. In one of his studies, he was able to create a window that allowed for researchers to see what was happening in live mice brains. They found that the number of surface proteins in mice brains dropped while they slept, and this was correlated with shrinking synapses. He was able to isolate a protein, Homer1A, as the pruning mechanism while mice slept.

Diering and his team also looked at how Homer1A affected learning. He tested two groups of mice, one with Homer1A and one without, by shocking them in a specific chamber. The next day, he brought both of the groups back to the chamber and both groups froze, remembering the shock they received earlier. He then moved the groups to different chambers and the mice without Homer1A froze again, while the normal mice explored the chamber. This suggests that the mice without Homer1A were unable to narrow down their memories to the particular chamber where they had received the shock.

Synaptic homeostasis hypothesis is still not definitively proven, however there seems to be some promising research on this topic. I am excited to see where this research goes in the future and what this synaptic pruning means for humans and what we remember after sleep.

https://www.nytimes.com/2017/02/02/science/sleep-memory-brain-forgetting.html

https://science.sciencemag.org/content/355/6324/511

PTSD and Alcohol

On October 22^nd, Dr. Michael Fanselow presented on stress enhanced fear learning (SEFL). This is used in a rodent model to demonstrate the effects of PTSD on a person’s response to mild stressors. Due to past trauma, the fear response to these stressors is triggered easily even in cases of little threat. Fanselow also went into how this impacted the lives of those who suffer from PTSD and how it impacts their everyday life.

I was curious to see how PTSD impacted one’s relationship with not only adverse stimuli but with positive stimuli as well. I found an article on the effects of alcohol and how the brain associates alcohol consumption after the trauma that occurred during intoxication. The article, published in Clinical Psychology: Science & Practice, Debra Kaysen discusses the effects that alcohol has on the development, severity, and recovery of PTSD.

Though there are many varying factors that play into the way alcohol consumption and PTSD in person who has experienced trauma one interesting point that was brought up was the motivational process that might be impacted by PTSD. First, they discuss that alcohol, though raising one’s risk for traumatic experiences, may actually help to prevent the formation of PTSD. When one consumes alcohol, it reduces one’s response and arousal to trauma exposure. In doing so the low levels of fear may impact the way a person processes trauma. Kaysen discusses the work of J. K. Langdon and who the level of alcohol consumption completely changes the way a woman develops fear conditioning. Those who had consumed low levels of alcohol before an assault showed a higher level of fear conditioning than those who had consumed high levels of alcohol. It is also discussed that alcohol may have an impact on the recovery rate of a person from a traumatic experience. Those who were intoxicated during a traumatic event had a slower rate of recovery.

 Though it could be argued that alcohol, if involved in the traumatic event/ events, may be seen as a trigger it was highlighted that it may also have a satiating effect of the anxiety that one experiences. PTSD, which is seen mostly for its negative effects on reward and motivation, may actually have motivational effects on coping mechanisms such as substance abuse and disassociation. I think that this is very interesting seeing as 70 percent of the population experiences trauma in their lifetime and the substance abuse problem in our country. Finding the connection between these may open a new door to recovery seeing as if one is using drugs or alcohol to cope with trauma then recovery is that much harder. By taking Fanselow’s research a step further and looking into the state of the person while the trauma occurred it may also impact how it is treated.

Kaysen, Debra, et al. “PTSD and Alcohol Associations Among Trauma-Exposed Women: Critical Questions for the Field.” Clinical Psychology: Science & Practice, vol. 24, no. 1, Mar. 2017, pp. 23–26. EBSCOhost, doi:10.1111/cpsp.12168.

Fanselow, M.S. (2016). “Induction and expression of fear and sensitization caused by acute traumatic stress.” Neuropsychopharmacology, 41, 45-57. PMC4677128.

PTSD and nursing

The first image that many have when they hear the word PTSD, an acronym referring to post traumatic stress disorder, is of one associated with the military. While those who have served, do make up a large portion of those who have PTSD, PTSD is not exclusive to just members of the military and can be a result of any kind of severe trauma and can affect anyone. By increasing awareness of PTSD as a disorder that can affect anyone and it’s prevalence in other fields besides the military, not only can more people find access to diagnosis and treatment, but better and more directed research can occur in order to find more effective treatment options. 

One of the professions  in which PTSD is especially prevalent is nursing. Since PTSD can arise after exposure to a traumatic event, which is most commonly involves death, injury, and sexual violence. This exposure can be both first hand as well as seeing  or hearing about it happen to someone else. Nurses repeatedly hear upsetting and stressful details regarding their patients as well as repeatedly being exposed to death and violence. Up to one in four nurses experience PTSD at some point.  Nurses are also involved in a variety of different stressful environments providing care to vulnerable and high risk patients, and as environments and patients become more challenging and distressing, incidence of PTSD also increases. A recent study found that nearly 48 percent of nurses who work in critical care met the criteria for PTSD symptoms. This not only presents problems for the nurses and medical staff, but high rates of PTSD result in high rates of turnover creating fewer more experienced professionals as well as nursing shortages. Since nurses will often have the most patient contact, this can affect medical care across the board.

While there is increasing awareness of PTSD affecting medical providers and as a result there has been a push for better working environments, this is often not enough due to the inherent nature of the job. One of the ways that many have hoped to reduce and alleviate PTSD in this field is through directed research focusing on mechanisms causing PTSD and more effective treatment options. 

On October 22^nd, one of the leading researchers in the field, Dr. Michael Fanselow of UCLA, hosted a seminar at Loyola University Chicago presenting his research on PTSD. While current research and treatment options are primarily focusing on behavioral responses and exposure therapy, Dr. Fanselow’ s research looks at non-associative model called stress enhanced fear learning or SEFL. This model theorizes that a large number of symptoms of PTSD are a form of sensitization rate her than the context or environmental cues surrounding the trauma. As a result of this Dr. Fanselow’s research looks at how the mechanisms of this sensitization behavioral response can be used to treat PTSD. One of the ways he believes is by blocking receptors in the amygdala. This type of revolutionary research may be used to help treat many of those who suffer from PTSD and help better the quality of healthcare provided as a result. 

Perusini, J.N., Meyer, E.M., Long, V.A., Rau, V., Nocera N., Avershal, J., Maksymetz, J., Spigelman, I., & Fanselow, M.S. (2016) Induction and Expression of Fear Sensitization Caused by Acure Traumatic Stress. Neuropsychopharmacology, 41, 45-57.

https://www.nytimes.com/2019/05/07/well/live/for-nurses-trauma-can-come-with-the-job.html

The Growing Popularity in the Research of Sleep-Learning & Memory Consolidation During Sleep

A fairly recent article on The Wall Street Journal explains a study that showed successful results in memory consolidation during sleep. The article, “Can a Person Learn While Sleeping?,” researches the effect of cementing memories, but also the ability to learn something new while sleeping.

A study on hypnopedia, also known as “sleep-learning”, was published back in 1965. This study utilized electroencephalograms (EEGs) to show that hypnopedia was a real thing that could occur. Later studies found out that the hippocampus was activated during non-dreaming parts of the sleep cycle. This is possible through “neural oscillatory activity,” which is the “up-and-down of wakefulness that occurs during Stage 2 non-REM sleep.” During Stage 2 non-REM sleep, one’s heart rate slows down and their body temperature decreases. Sleep spindles, known as the “up-down” moments, play a key role in sensory processing and long-term consolidation of memory, lasting only half a second to two seconds maximum. These spindles help the brain communicate across different areas of the brain, helping it to transfer data to the proper location.

The article then explains a study performed at the University of Zurich, where 68 German students who participated were asked to learn some words in Dutch before 11p.m. each night. Half of the students had the words played to them while they were asleep while the other half stayed awake while listening to the words. After three hours of sleep, all students were tested at 2 a.m. on their memory of the new words they had learned. Results showed  that the students who listened to the words while asleep were able to recall more of the vocabulary and had a better memory of them than those who did not sleep. EEGs were used to prove that sleep deprivation was not the reason as to why those who stayed awake had poorer memory. The results of the EEG tests showed significant findings, indicating that the “up” phase of spindles played a key role in sleep learning. Two other studies used cues, such as smells or sounds, paired with new information on participants. Participants were able to retrieve the information learned while asleep, having no recollection of how or when they learned this information.

I found that this article closely resembled the topic presented in our last seminar lecture by Dr. Eitan Schechtman-Drayman. His work was based on the use of cues to help in memory consolidation during slow-wave sleep. To study this, he used TMR, targeted memory reactivation, which helps in the formation of memories through cues during sleep. Tests which were performed include spatial-memory tasks. His findings showed that  TMR greatly helped in memory consolidation and modification of knowledge through processes of integration, reorganization, and generalization. Lastly, Dr. Eitan Schechtman-Drayman found that sleep spindles do play a key role in his findings.

Both the article and Dr. Eitan Schechtman-Drayman showed the importance of memory consolidation during sleep. The findings presented give the reader a clear view of what is being presented but also how it all works. Personally, I believe that sleep is important, and even more crucial than we thought it was, especially in the consolidation of memory. All in all, sleep-learning is a new interest in the field of memory consolidation and is becoming more popular among researchers and the everyday person.

Article link:
https://www.wsj.com/articles/can-a-person-learn-while-sleeping-11552744800?mod=search results page=1&pos=7

The complications & consequences of Neuroethics around the world

           The importance of neuroethics has been gaining attention for the last 50 years or so. When a discussion of this sorts comes up it usually has to do with scientists trying to experiment and research on humans or animals. One of the guests that I had the privilege to listen to the talks of was Dr. Joe Vukov. During his talk, he explained the significance of neuroethics. Most of his lecture was focused on the research done by Molly J. Crockett on the topic of neuroethics. She explains in her work how our judgments and decisions that we make on a daily basis can be affected by the neurochemicals in our brain. She states that “our moral views are influenced by neuromodulators”. This can mean that every person can potentially have a different set of neurochemicals in their body that can react differently thus creating the varying differences in morality and ethics all across the human population. Hence when the topic of ethic comes up not just in neuroscience but in general life, everyone must be cautious of these differences when doing research or experiments involving ethical practices. The main two researches that can be subject to this is ones with the use of humans or animals. For example, with humans the issue of consent is very prevalent. Consent is needed for any type of human that is being involved in a study, so if there is an imbalance of neurochemicals in a person due to some underlying disease this can cause an issue. A person needs to be of sound mind and body in order to approve anything or give their own consent. These are the types of problems that arise when dealing with these delicate issues.

            A real-life example of neuroethics not being used in the right way is found in a neuroscience article talking about the ban that is currently placed on immigrants coming into the United States. It states that neuroscience the field itself was fully coined around the 1960s. Once the Society of Neuroscience was founded, the idea was able to be shared globally with other researchers and scientists around the world. They stated that the first annual meeting of this society was in 1971 and had drew in about 1,500 researchers and scientists. This year they had an attendance of about 30,000 people. Now that is a very dramatic change but that is also because the field is growing rapidly. All these attendees are coming from different countries all around the world to share and portray their knowledge of the field they all are exploring. This is very important when it comes to global unity in the understanding of some topics. With the closing of the national borders by the Trump administration, it was very hard to accomplish this. Many members were unable to get visas to enter the U.S. because of this travel ban which has restrictions on people entering the U.S. from specific countries. This creates problems for many people across the world. The new research and knowledge that is being gained should be shared with everyone.

            Is banning researchers and scientists from entering the country an ethical way for conducting research? The talks of neuroethics doesn’t necessarily have to be confined in the actual study but can also include the ethics of the way things are done. Some may argue that the travel ban is necessary for keeping our country safe from people that are trying to cause harm, but I don’t think it should be applied in this case. When it comes to science in general, everything should be an open book because topics like neuroscience that are relatively new need to be sought through and figured out. By limiting the potential research from excellent scientists across the world is being negligent. Politics does play a major role in the rules and regulations of many things across the globe, but science and research should be widely shared. Gaining new perspectives from different people is very educational and gives a holistic approach to any problem. Should there be limitations on people entering the country? Maybe. There should also be additional resources that can verify the identity of many of these people in order to allow them to showcase their findings with the rest of the world.

Works cited:

Crockett, M.J. (2016). Morphing Morals. Moral Brains, 237-245. doi: 10.1093/acprof:oso/9780199357666.003.0011

Stix, Gary. “Society for Neuroscience at 50 Delves into Mini Brains, Gene Therapy, Prosthetics and All Else Related to Our Three-Pound Wonder.” Scientific American Blog Network, Scientific American, 28 Oct. 2019, blogs.scientificamerican.com/talking-back/neuro-society-at-50-delves-into-mini-brains-gene-therapy-prosthetics-and-all-else-related-to-our-three-pound-wonders/.