Can It Ever Be Too Much? The effects of epinephrine on the brain
Why seek to scale Mount Everest,
Queen of the Air,
Why strive to crown that cruel crest
And deathward dare?
Said Mallory of dauntless quest
`Because it's there.'
-Robert William Service
Inspired by George Mallory, a British mountaineer, Robert William Service’s poem, “Dauntless Quest”, poses a very interesting question (1). Why risk everything to climb one of the most dangerous mountains in the world for no tangible benefit? Or for that matter why risk losing your life for fifteen minutes of an adrenaline rush? For many years, extreme sports such as bungee jumping and skydiving, have appealed to many people despite the threat they pose to a person’s life. Personally, I have not partaken in many forms of extreme activity, but as strange as it sounds, I would very much like to satisfy my desire to jump thousands of feet out of a moving plane.
Epinephrine, also known as adrenaline, is a hormone released by the adrenal medulla through the sympathetic nervous system during an individual’s fight or flight response (2). If a person is in danger, the body’s endocrine system interacts with the nervous system to give the individual the ability to attack the threat or to take flight and run away. Epinephrine is a person’s natural boost of energy, and it is the hormone that gives college students the ability to write their ten page papers the night before the deadline, or for a mother to lift up a car in order to save her children. The secretion of epinephrine is controlled by the adrenal medulla, located near the abdomen, and the release is stimulated by a relative increase of either physical or mental stress. The hormone travels through the bloodstream and increases heart rate, blood sugar, and it increases an individual’s metabolic rate in order to produce the most amount of energy for the individual to utilize. As with other hormones, there is a normal level of epinephrine that is naturally in the brain and there are regulatory proteins that maintain a healthy balance. If the brain is under constant stress, more adrenaline is secreted through the adrenal medulla in order to satisfy the body’s needs. This is where the problem begins.
We live in an ever-changing and very fast paced society, where people must be constantly active and busy in order to keep up with the competition. Yes, there are energy drinks and pills that artificially provide the body with energy to get through the day, but adrenaline is the body’s all-natural energy boost. Living in a constant state of energy is not a healthy lifestyle because the brain is already continuously exposed to a plethora of stimuli, half of which are not consciously processed and by adding more stimuli for the brain to process the brain to fatigue much more quickly. An exhausted brain will not be much help when you are trying to perform trivial every day tasks. As with most addictions, the necessity to satiate a desire become overwhelming, and consumes the individual’s thoughts and actions. Adrenaline junkies are people who have a constant craving for the next high. The more times they achieve the adrenaline high, the more adrenaline they need to feel the same effect and the levels of adrenaline in their bloodstream eventually become very imbalanced. Adrenaline junkies mentally process everyday activities into emergencies in order to find ways to fulfill their quota of adrenaline. Without the constant secretion of the hormone in the bloodstream, an addicted individual can experience adrenaline withdrawal. Symptoms such as panic attacks, exhaustion, irritability, and restlessness are common to those who are incessantly on the move (3). Although there are no obvious physical symptoms, the mental symptoms that an individual experience are strong enough to alter moods and personalities.
Tests performed on rats have shown that an increased exposure to epinephrine increases the sensitivity of the sensory neurons (4). This means that when there are increased levels of epinephrine rats are more excitatory and capable of doing much more work. Although this experiment did not describe the after effects of the epinephrine exposure, I would predict that the rats would undergo a period of withdrawal because their hormones would need to return to their standard levels. Also, epinephrine injections are used to treat severe forms of allergic reactions (5). Commonly, the injections are administered incorrectly and the result is abnormally low blood pressure, which is a serious side effect to an overdose of epinephrine.
The consequences of persistent physical and mental stress prove to have negative effects on the body as the levels of epinephrine in the bloodstream become distorted. However, despite all the information that is available, people will still jump off the side of a bridge, in order to get that one-of-a-kind high. I have willingly sat in the third seat of a roller coaster that dropped 150-foot at 120 miles per hour, and I can say, it was one of the greatest experiences of my life.
1) http://www.askoxford.com/worldofwords/quotations/quotefrom/mallory/; World of Worlds
2) http://stress.about.com/od/stressmanagementglossary/g/Epinephrine.htm; The Definition of Epinephrine
3) http://www.newhopenow.com/notes/archive/adrenaline_dependence.html; Hurry Up and be Still: Freedom from Adrenaline Dependence
4) http://jap.physiology.org/cgi/content/abstract/102/4/1545; Epinephrine enhances the sensitivity of rat vagal chemosensitive neurons: role of B3-adrenorecpetor
5) http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16861845&query_hl=7&itool=pubmed_docsum; Too much of a good thing, is it bad? Adrenaline on trial