"The Science of Appetite" By Jeffrey Klugger

Jeffrey Klugger's 2007 article examines how the human appetite develops and why humans overeat. Hunger is a natural feeling for us as human beings because we need food for survival, but we are not born already having cravings for specific foods. In the article Klugger uses a cupcake as an example, he explains that somewhere in your brain there is a cupcake circuit but that circuit is not something you came out of the womb already having. It was formed when you had our first cupcake and at that moment sensory, metabolic and neurochemical signals went off, your stomach began to release digestive acids, your pancreas began to secrete insulin, your liver began to work to take in the sugar, fat, starch, and the mesolimbic region in your brain that processes pleasure developed the idea that cupcakes are good. Klugger describes human being's relationship with food as complicated because even though food is essential for our bodies to function, we overeat and it it has caused for 67% of the american population to become either overweight or obese. 

Like all other animals, humans are creatures of dietary habit and when we continuously eat at certain times of the day, our body learns to get hungry at those times. Our cravings for food are caused by a hormone called ghrelin. It is also known as the hunger hormone, it is produced in the gut when we get hungry. Ghrelin travels to three parts of the brain, the part the controls unconscious processes, the part the controls metabolism, and the part that controls our feelings of pleasure and satisfaction. Ghrelin is released when it is mealtime and afterwards, cholecystokinin CCK is a peptide released by the upper intestine to let the brain know it is time to stop eating. CCk, however, does not last until the body really needs more fuel which is why people will eat again even thought they are not hungry.  GLP-1 and PPY are hormones that actually stop the hunger feeling, and are the reasons why one can eat at 8:30 and feel full for the rest of the night; they send signals to the brain and to the stomach telling it to stop what it's doing and not move anymore food along the intestines. Another hormone, leptin is produced by body fat. Those with a lot of body fat produce so much that their body grows a restraint to the hormone and it no longer suppresses the appetite. Other causes of overeating in humans are malfunctions in receptors in the brain that are pathways for the hormones.

The reason people overeat is sometimes mental making it really hard to create a drug to control the appetite so humans have to learn to eat foods that are not empty of nutrients and satisfy their appetites to the fullest. Humans must also learn to balance the foods they eat so they do not have such strong cravings for certain foods, causing them to overeat. People need to become more health conscious when it is mealtime.

TONE

Objective

Application

How do you think society has contributed to the creation of humans' habit to overeat?

"A New Approach to Correcting Autism" By Claudia Wallis

Claudia Wallis's 2007 article explains how researchers are making efforts to find medication to treat autism. The cause of autism is still a mystery, but it has been discovered that the disorder has something to do with genetic defects. One specific genetic defect is a malfunction in the X chromosome which results in a condition known as the Fragile X Syndrome. A paper published in the journal "Neuron" showed that symptoms of Fragile X--epilepsy, impaired metal functioning, aberrant brain structure and other abnormalities of the brain--could be reversed, thus providing hope for those with Fragile X and autism. 

Fragile X is a cause of the brain's failure to produce regular quantities of a chemical called the Fragile metal retardation protein FMRP. FMRP hinders the production of other proteins in the brain and without the proper amount of FMRP protein production becomes chaotic causing the brain to develop a large number of connections and a variety of behavioral, physical, and mental problems. FMRP is able to stop excess protein production by attaching to receptors on the surface of brain cells known as mGluR5 receptors, however the excess Fragile X blocks the receptors, accelerating protein production. After conducting an experiment on a special breed of mice with Fragile X researchers concluded that Fragile X could be treated by providing a drug that inhibited mGluR5 receptors. Fenobam, an already existing mGluR5 inhibiting drug, will be tested for human safety starting this year. 

TONE

Objective

Application

Have you ever knew anyone with autism? Do you think this disorder can be completely reversed? How do you think other people will respond to the development of this medication?