Saturday, 24 March 2012

Mike the Headless Rooster and The Brainstem


Mike the Headless Rooster
The brains of humans and other animals are divided into different areas responsible for different functions. In humans and other mammals, the three basic areas of the brain are
·         The cerebrum, the large upper part of the brain that is responsible for all voluntary and conscious activities, such as voluntary movement, sensations such as sight, hearing and touch, intellect and logic, memory, the voluntary portion of emotions, language and so on. The cerebrum is particularly large in humans and other primates.
·         The cerebellum, a smaller highly folded lump of brain at the back of the cranium, which is responsible for involuntary control of balance and coordination.
·         The brainstem, which is responsible for the control of life processes such as heartbeat, breathing and digestion.
Only the brainstem is absolutely essential for life. Destruction of the brainstem removes the brain’s ability to control heartbeat and its ability to stimulate breathing. On the other hand, damage to the cerebrum, for instance due to trauma or a stroke, may interfere with memory, movement or sensation, but does not have to be lethal. Similarly, damage to the cerebellum, be it from trauma, alcoholism or other, may interfere with the ability to walk, run or ride a bicycle, but again is not fatal.
The fact that a body can survive with only the brainstem intact is witnessed by the tragic condition called anencephaly. A fetus that develops with anencephaly develops without a cerebrum. Many of these fetuses miscarry before term, and of those that survive pregnancy most are stillborn, but some survive to full term and are born alive. These children, missing the part of the brain responsible for conscious thought, can never be considered fully alive, but in a technical sense they are living, because their hearts beat and they breathe, all because their brainstem is intact. These children, if they can correctly be called children, eventually succumb, although anencephalic infants have survived for up to several years. It is interesting to note that these children can also breast feed, indicating that these functions are also unconscious activities controlled by the brainstem.
This leads us to Mike the Headless Rooster. Mike, the property of farmer Lloyd Olsen from Colorado in the USA, was chosen to be the centerpiece of the dinner table on September 10, 1945. Lloyd’s mother-in-law was visiting and Lloyd, knowing that his mother-in-law was partial to the neck of the bird, chose to sever Mike’s neck as close to Mike’s head as possible. Inadvertently, the axe severed Mike between the brainstem and the rest of the brain, leaving the brainstem still attached to the spinal cord within the headless body. Although it is not recorded exactly what happened in the minutes that followed, what we can infer is that Mike’s body did not “die”. Of course, Mike’s body was no longer capable of conscious thought, but having a brainstem, breathing continued, albeit through the newly-severed trachea opening in the neck.
It is remarkable what Mike’s body was capable of doing, even when the upper parts of the brain were no longer present. Mike could walk (having no eyes, he walked aimlessly), flap his wings and even peck blindly at the ground. Mike could even be seen to ‘sleep’ by tucking his phantom head under his wing. All these functions are controlled by the brainstem and spinal cord, and removal of the head poses no barrier.
Decapitated roosters are known to run around the farmyard for several minutes before succumbing to blood loss. The reason that Mike did not bleed to death can only be guessed at. Perhaps blood clots in the major arteries of the neck prevented exsanguination.
When it became apparent to Lloyd that Mike’s headless body would not die, Mike was taken on tour. He toured the United States for 18 months. Lloyd fed Mike by using a syringe to squirt liquid food into his open oesophagus in his neck. It was also necessary for his owner to periodically clear Mike’s trachea, to prevent the buildup of mucus. Unfortunately one day this was not done and Mike asphyxiated, ending Mike’s career as a celebrity.
Others have tried since then to replicate the Mike experience, but without success.

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