Stress is an interesting body response that is stimulated by our brain due to incoming auditory, visual and/or somatosensory signals. It is how we feel and how our body reacts when we encounter an imbalance in the normal rhythm of life. Watching a horror movie, coming face to face with a deadly creature or simply feeling overwhelmed due to daily tasks may all evoke stress. How does our brain respond to a stimulus that elicits fear and anxiety?
The key areas of the brain that are involved in stress are the thalamus, hippocampus, amygdala, and the prefrontal cortex. The thalamus located in the forebrain processes the incoming visual and auditory signals and relays them to the prefrontal cortex and the amygdala. The prefrontal cortex is the hub for executive function. With respect to stress, it gives meaning to the relayed signals and makes us conscious of what we see and hear. This part of the brain is also critical for ‘turning off’ the stress response once the condition is passed.
The amygdala is the emotional center of the brain and is responsible for triggering the stressful response. It is a part of the limbic system and is located deep within the temporal lobes of the brain. The amygdala also drives the body’s sympathetic nervous system to initiate anxiety that is associated with stress. This includes increasing the heart rate, blood pressure, hyperventilation of the lungs and increasing perspiration.
Finally, the hippocampus located in the medial temporal lobe stores the memory linked to a particular stress response and allows the brain to access these memories when the same visual and auditory triggers of stress are encountered later on.
It is also essential to mention the role of the hypothalamus and the linked pituitary gland that pumps out high levels of cortisol – “the stress hormone”. Recent studies suggest that cortisol can damage and kill brain cells, especially that in the hippocampus. (The hormonal response of stress is in fact a huge area of study with lots of factors involved.)
A critical question in this area of study that interests me is, “How much stress is bad for us? Can a little stress actually be helpful?” It turns out that acute stress (short-lived, unlike chronic stress) may actually be good for us. New research suggests that it conditions the brain for improved performance by inducing an increased level of alertness, behavioural and cognitive performance. This may explain why we get most of work done when we’re under pressure!
I am excited to have successfully completed my first ever massive online open course, “Understanding the Brain: The Neurobiology of Everyday Life” with distinction. Taught by Professor Peggy Mason at The University of Chicago, this 10 week course was one of the most interesting and engaging classes that I’ve been a part of. The best aspect of the course was how involved everyone was, including Dr. Mason and her student assistants. The lectures were well organized with weekly quizzes and corresponding lab videos (which included sheep brain dissection among many other things) and discussions related to current news revolving around neurobiology.
It is motivating to be a part of a community that takes time out to learn something new. E-learning is an awesome platform to explore diverse subjects along with people from all over the world. It is also a great opportunity to learn from some of the best minds in the respective fields. I am already looking forward to my next course!
McDonald Observatory – located in the middle of a vast desert.
The Smith Telescope has a 2.7-meter (107-inch) mirror, which was the third largest in the world when built.
Last month, I visited McDonald Observatory, a research unit of The University of Texas at Austin. The observatory of situated in West Texas, an area that experiences some of the darkest night skies in the continent. The location thus makes it perfect for astronomical research and star gazing during night times (along with experiencing the least white pollution due to its location). I attended three events at the observatory – solar viewing, twilight program and star party. The solar viewing program in the afternoon consisted of watching the majestic sun on a huge screen in real time. It was an informatory session that introduced the audience to the concepts of sunspot formation and solar flares. The session concluded with a tour of the 107 inch and the 82 inch telescopes. The twilight program in the evening was about “Modelling the Night Sky”, and was followed by a star party in the night. Many telescopes were set up for the public to view saturn, binary star systems, nebula, moon craters, and other celestial objects up close. It was magical treat for the eyes.
From the wild desert of the south, I travelled up north to the land of the midnight sun – Alaska! For the first time in my life, I saw – caribou, a wolf, moose, grizzly bears, dall sheep, orcas, humpback whales, puffins, murres, sea otters, bald eagles and many other animal species. The abundant and diverse wildlife of Alaska has left me stunned and speechless. Also, during the journey, I developed a deep admiration for the field of Geology. It was interesting to witness all the geographical occurrences that I once briefly learnt back in high school (and so easily forgot). Walking on glaciers and observing braided rivers triggered a sense of appreciation for all the geologists who battle extreme weather conditions to understand our planet better and discover its glorious history.
The last month has been a roller coaster ride across amateur astronomy, ecology, geography and surely lots of biology. I’m now back at school and ready to do some awesome science in the lab with a whole new perspective on the world. Photographs from my Alaskan adventure can be viewed on my photoblog, here.