Welcome to a new semester! In the next few months, we will be writing a series of blog posts to help you understand the biology and neurobiology of stress and ways to alleviate, to help you study and live healthier! First up - what is stress, anyway?
There’s no doubt about it – being a student can be stressful. From scheduling classes and waitlists, to taking exams, to waiting on grades, to lining up a summer job, to managing roommate drama, to making sure you on are track to graduation, to deciding what you will “do with your life” when you finish school, stressful events lurk in every corner. No matter how prepared you are, there’s always going to be a failed grade, a missed deadline or a miscommunication with a professor here and there.
But what is stress? Stress can be defined as a behavior or physiological change in an individual in response to a real or perceived stressor. Not all of us perceive the same stressors in the same way, however, meaning that one person may deal with a stressful event and remain happy and healthy, while another may become anxious and ill as a result.
“Stress is complex, fascinating and important,” Christine Lattin says. Christine is a new assistant professor in the LSU Department of Biological Sciences. She is studying the changes in physiology, behavior and immune function when birds are chronically stressed, both in the lab and in the field. She is most interested in identifying the differences in neurobiology and physiology that determine how stress resilient or stress vulnerable individual animals are, even within a single species. It’s important to study stress in birds and other animals to determine the potential impacts of environmental changes like habitat destruction and climate change. We can also learn from how animals respond to stress, to better respond to stressful events ourselves.
“Fortunately, there’s a lot that we know helps alleviate stress,” Christine said.
When Christine was an undergraduate student, she was a linguistics major and a biology minor. After college, she worked at a wildlife rehabilitation center for birds of prey that had been injured through car collisions, through infectious diseases and other trauma. Christine became intrigued by how different birds would handle the stress of being brought into captivity very differently. Some birds would eat well and appeared calm, while others were obviously stressed, jumping around their cages and hardly eating.
“I started getting really interested in this individual variation, both within a species and across a species, in stress response,” Christine said. “What is it that makes some animals and some individuals resilient to stress, while others are vulnerable to stress?”
When Christine went back to graduate school to study biology, she started to explore her questions about stress in the context of birdsong in the blue grosbeak. She discovered through studying these birds that males change their song based on different environmental factors, from the presence of female birds to the presence of competing males. But one spring during her fieldwork in eastern Kentucky, she was surprised to find that following a particularly early, harsh freeze, none of the Blue Grosbeaks were singing.
“I was like wow, look at this! This big environmental stressor came, and there was nothing for these birds to eat, and they are responding with a huge change in their behavior that is perfectly appropriate. Things aren’t good for them right now, so they are going to put a pause on their breeding until conditions improve,” Christine said. “This is an example of how stress responses can be good for animals, improving their survival and reproductive success through behavioral change.”
The lesson that we can learn from blue grosbeak is that stress can actually be a very good thing for us, even physiologically. It’s when stressful events and our responses to them last for too long that our mental and physiological reactions to stress can turn into a bad thing and harm our health.
“Stress is evolutionarily ancient,” Christine said. “Stress responses are found across all vertebrates, from fish, to reptiles, to birds, to people. The physiology of the stress response is really similar across many of these animals, including us, because it helps boost survival. Short-term stress helps you live to fight another day.”
Learning about Stress from Fish
Karen Maruska, an associate professor in the LSU Department of Biological Sciences, also studies stress responses – in fish.
In fishes, there are physical and environmental stressors like variations in water quality, excess noise and predation pressure, as well as social stressors such as territorial and reproductive interactions between individuals within the population.
“The cichlid fish we study in the lab is very social, and they do show behavioral and physiological signs of stress,” Karen says. “Similar to many social species, they typically show signs of stress when they’re isolated and not interacting with other individuals. There are coloration changes, reduced social behaviors and many physiological changes ranging from circulating hormone levels to cell proliferation in the brain.”
In the fish that Karen studies, defending one’s territory can be a significant source of stress.
“The males of our cichlid fish are either dominant and territorial or subordinate and non-territorial,” Karen says. “The subordinate males frequently get chased and beat up by the dominant males, which can be a source of chronic social stress. To protect themselves, the subordinate males often fade their body coloration and assume more submissive-like behaviors rather than fight back. By doing this, they become less of a target for the attacks from aggressive dominant males, protecting themselves from injury and the repeated stress of constant bullying. This is a common problem for many animal species that live in dominance hierarchies.”
Fish also show signs of stress when introduced to a novel environment – just like you might be feeling uneasy after just moving to a new apartment or starting a new course with classmates and a professor you don’t know.
“Broadly speaking, some of the stress responses in the fish are similar to that experienced by humans; for example, multiple overall effects on behavior and physiology,” Karen says. “It’s also important to recognize, however, that stress responses can be very species-specific as well as context-specific, and we don’t yet know how similar or different stress responses might be between different fish species and humans.”
Good Stress, Bad Stress
Stress in small doses can be healthy and helpful to your survival. It can help you study harder for an exam, prepare for a public speech, jump out of the way of a moving vehicle on campus, and lock your doors at night. But when acute stress becomes chronic, or when your body continues to respond to stress once the stressful event is over (have you ever gotten sick several days after a difficult exam?), stress can become very harmful.
“Once the stressful event is over, there has to be a way for your body to shut down the stress response. Your body needs to know that it is safe and to get out of that stress mode,” Christine said.
There are two main types of stress responses that take place in your body. The first and faster one is commonly known as the fight or flight response. This response involves your sympathetic nervous system and release of the hormone and neurotransmitter (brain signaling molecule) epinephrine, otherwise known as adrenaline. Seconds after a stressful exposure, this response increases your heart rate, diverts blood from your digestive system to your muscles and heightens your perception.
Other animals experience fight or flight responses to stress – even fish.
“There is evidence that changes in social behavior are used by fishes to cope with social stress,” Karen Maruska says. “In a recent study from our lab, for example, we found that under conditions of repeated social defeat – a resident male being aggressive towards an intruder – males often started using both “reactive” (fleeing or hiding) and “proactive” (trying to escape) behaviors. They then simultaneously increased their proactive and reduced their reactive behaviors over several days. Once they reached a threshold proactive behavior level, if the social defeats continued, they then switched to more reactive behaviors. These changes in behavioral coping were also associated with distinct neural activation patterns in the brain, revealing links between the behaviors and brain function. This study also revealed that different individuals respond and cope differently to the same stressors, and that the coping behaviors within one individual can also change over time. Both of these scenarios are also quite common in people.”
The slower stress response is the glucocorticoid response. Your brain sends signals to your adrenal glands to secrete glucocorticoids like cortisol, hormones that signal to the rest of your body to respond to the stressful event that caused your brain to send the “react” signals in the first place. This hormonal cascade starts just a few minutes after a stressful event. The glucocorticoid response helps mobilize energy for you to fight the cause of your stress (or run away) and shuts down some non-essential functions of your body, including the immune system and reproductive function. You can see where this would be a bad thing, if your stress hormone levels stay elevated for too long, or if you never really recover your normal stress hormone levels from one day to another due to a string of stressful events during the semester. When your cortisol levels get too high, your body has negative feedback systems that normally help bring these levels back down after a short period of time. However, chronic stress can lead to stably elevated cortisol levels that can be harmful to your health.
“This is why people who suffer from chronic stress can have digestive problems and get sick more easily,” Christine said. Chronic stress can cause gut health problems, heart problems and immune system problems. People who suffer from chronic stress can even respond poorly to vaccines, due to a depressed immune response to the virus fragments used in a vaccine to help create immunity.
If you get the flu shot this year, you could still get the flu if you get vaccinated during a period of high, chronic stress levels.
Keep Your Stress Responses Short and Sweet
Yes, college can be a stressful time. But the good news is that there are things you can do to alleviate your stress levels and physiological responses to stress.
First of all, if you are in an extremely stressful situation, a dangerous situation or one in which you don’t feel safe, seek help and distance from this situation. Whether it’s a health issue, a financial issue, or a home, sexual assault or other physical safety issue, seek help from a family member, a friend or an appropriate LSU professional. The LSU Student Health Center can help you with various physical and mental health needs.
There are other stresses that as students, you can’t and probably shouldn’t get away from, like exams, essays, job interviews, public speeches and quizzes.
“In these situations, students can help manage their stress with various coping mechanisms, like exercise,” Christine said. “There’s really good research showing that exercise is amazing for managing stress. It’s interesting because exercise actually raises your cortisol levels temporarily. But having a routine where you regularly exercise brings down your cortisol levels overall and helps manage stress. This is true for cardiovascular, vigorous exercise, as well as more gentle and mindful exercise like yoga. There’s research showing that mindful breathing and mindful, moving meditation helps control sympathetic nervous system activation and bring down cortisol levels.”
Other interventions that can reduce physiological stress responses and stress hormone levels include adequate sleep and social support.
“The benefit of social support for stress has been seen in animal studies as well as in human studies,” Christine said. “Animals that live in social groups help manage stress through what’s been called a tend-and-befriend response, referring to protecting offspring and seeking out social groups for support. You can help manage your stress by talking to loved ones, friends and roommates. It’s important to feel part of a connected community and not isolated. This is incredibly important for both social animals and humans to alleviate stress. The strength and size of your social network are actually some of the strongest predictors of human lifespan and health in older age (in animals, too).”
Another more harmful way to alleviate stress, seen in both animals and humans, Christine says, is beating up on others. Christine sometimes sees this response in the sparrows that she studies – these birds sometimes peck at each other when they are stressed.
“This is something students should look out for in their own behavior,” Christine says. “If you feel like lashing out when you are stressed, it might make you feel better temporarily, but it is destructive to others.”
You, On Stress
Christine is also interested in how individuals, whether birds or animals, respond to stress in different ways based on personality. For example, a balanced diet full of anti-inflammatory fruits and vegetables can help alleviate the negative impacts of stress and lack of sleep (the impacts of those late-night study sessions) on your body, including oxidative stress and inflammation. However, we tend to seek out sweet or fatty foods when we are stressed, which can lead to weight gain as well as elevated levels of inflammation in your body that can lead to health issues.
To help yourself stay healthy during high-stress periods in the semester, try to plan ahead in order to eat healthy. Bring balanced meals with you to campus, with lots of whole grains, fibers, vegetables and raw fruits, or plan your schedule out so that you can stop by the LSU union for a veggie bowl or fruit cup between classes. Avoid vending machines full of chips and candy bars.
Karen Maruska copes with stress with relaxing activities like walking outside, listening to music, exercising, drawing, painting, taking photographs, watching movies or reading.
“Basically I just take a break and focus on something other than what might be causing the stress,” Karen says. “I think one of the keys to de-stressing for everyone is being able to recognize what the sources of stress are for you, notice when you’re experiencing it, and then find a way to take a break and alleviate it as often as needed so it doesn’t become a chronic thing.”
Christine's favorite ways of de-stressing are cuddling with her baby, going for a swim in the LSU UREC outdoor pool, talking a walk in the woods or a natural area, and calling her mom (even professors call their moms!).
Stay tuned for future blog posts in this series to learn more about interventions for stress, including eating a balanced diet, sleeping at least 7-8 hours every night and maintaining a good circadian rhythm, and practicing mindfulness activities like yoga!