Trippin' on Tryptophan

Turkey and its associated essential amino acid L-tryptophan have long been blamed for the inevitable lethargy that follows the Thanksgiving meal. Does turkey really deserve this reputation? Not so much. L-tryptophan can be metabolized into serotonin and melatonin, which would explain the sleepy after-effect. However, the relatively low levels of L-tryptophan in turkey will typically cause drowsiness only when consumed on an empty stomach. When’s the last time you saw a family member sit down to a big plate of turkey (and nothing else) on Thanksgiving?

So what’s really causing ‘the itis?’ More than likely, it’s the carbo load associated with the Turkey Day meal. Stuffing, roles, mashed potatoes, pie...the list goes on. When we consume a ton of carbohydrates, insulin is secreted by the pancreas, forcing amino acids that would typically compete with tryptophan to move from the bloodstream to muscle cells. L-tryptophan can then be synthesized into serotonin and melatonin, inducing that naptime feeling.

Some more possible causes? Any time you eat a large meal, your body’s blood supply will flow away from the brain and towards the digestive system. Your energy reserves will take a serious hit as your body works hard to digest a feast. Let’s not forget booze. In my family, jell-o shots and beer are equally as essential as cranberry sauce or green bean casserole to the traditional meal. Alcohol acts as a sedative, enhancing the effects of the overall meal.

And let’s be honest, some of us are looking for any excuse to catch up on some z’s. Happy napping,
all!

http://chemistry.about.com/od/holidaysseasons/a/tiredturkey.htm

Celebrating Uncertainty

Watch this video! But it’s so long, I know. Do it anyway! Because not only are optical illusions fun, but you’re probably going to learn a thing or two about perception and the human experience.


We've all seen optical illusions before. A typical response is something like "Wow...I guess my senses are tricking me; I guess I know less about my surroundings than I thought." Lotto does something truly profound with optical illusions. He appreciates the gaps between reality and our own perceptions, he sees these inconsistencies as windows into the brain and its functioning. As he explains, “context is everything.” Our awareness of the physical world is limited by our perception, a system that we know can be fooled. According to Lotto, there’s nothing wrong with the inaccuracies in our perception, they’re proof of the patterns in the world on which we base our experience. If humans weren’t able to transform the overwhelming amount of stimuli invading our sensory organs into a concise representation, we wouldn’t be able to function. Lotto explores how our experience-based expectations can be modified and combined. He looks at optical illusions in other species, something I had never considered before. He also explains how one sensory modality can be transformed into another, without a loss of understanding. Fascinating stuff! I don’t know about you, but I’ll be paying a little more attention to my perceptions from now on.

Who Needs Accurate Memories, Anyway?

Last year, Cambridge researchers stumbled across some revealing data on false memories. They were studying the effects of brain damage on memory in rats. Rats were presented with a small, elaborate object and given time to become familiar with its appearance. They were then placed in a normal cage environment, free of wacky objects, for an hour. When presented with the same object as before as well as a new object, rats without brain damage spent significantly more time exploring the new object, ignoring the one they’d seen an hour before. The researchers expected that rats with damage to the perirhinal cortex (involved in visual memory consolidation) would show no preference towards the previously shown object. The brain damaged rats took this hypothesis a step further. They actually spent LESS time investigating the new object than the normal rats, implying they had some sort of familiarity with the object, despite having never seen it before.
 

These findings propelled the research team into a new focus. They wondered if the stimuli in their regular holding environment, coupled with perirhinal damage, resulted in formation of false memories. To test this theory, a similar method was used, but rats were raised in a dark room, devoid of visual input. The visually impaired rats acted as the researchers had initially expected for rats raised in lit cages, supporting their hypothesis.

So what’s going on here? The perirhinal cortex is easily harmed in comparison to other brain areas. Damage to this area is common in diseases classified by memory impairment, such as Alzheimer’s. As it turns out, individuals with these impairments actually perform better on tests of memory if they’ve been in a dark, low-stimulus environment before testing. Connections, connections! According to the Cambridge researcher Lisa Saksida, the perirhinal cortex is responsible for formation of complex visual memories. When the area is damaged, less specialized regions will attempt to recreate memories using generalized environmental stimuli. This disadvantaged form of memory reformation produces what we know as false memories. Could the perirhinal cortex also be involved in sensations of déjà vu? Flashbulb memories? Who knows! I look forward to seeing more research emerge on this subject.

The original article can be found here: http://www.sciencemag.org/content/330/6009/1408.abstract

Cocaine and Cupcakes, One in the Same?

While home in Minneapolis this past weekend, I took some time to catch up on recent Star Tribune articles. I came across the intriguing title, “Some foods as addictive as cocaine?” Apparently, 28 papers on food addiction have been published in this year alone, according to the National Library of Medicine. This is a hot topic, and the food and beverage industry is nervous. Researchers are picking apart the brains of food addicts and obese individuals to understand what makes them addicted to food. It is becoming clearer and clearer that the delicious beverages and foods we love can “hijack the brain in ways that resemble addictions to cocaine, nicotine and other drugs.”

Like me, you may be thinking to yourself “well, duh.” The human body has not evolved for the abundant, sugary, fatty foods common to American culture. The foods we tend to love most are also those that are the worst for us (fries dipped in ice cream, anyone?). Sugars and fats were rare in the hunter-gatherer’s environment, and they taste so great because of evolutionary pressures to search long and hard for them. When you only have access to fats and sugars once in a while, an affinity for them becomes essential for survival. Aside from searching the aisles for the items on our grocery list each week, we don’t do much hunting or gathering these days. The well-liked flavors that once helped us prosper are now killing us. As it turns out, not everyone appreciates this, which is why so many researchers are looking at the mechanisms behind food addiction. They need factual collateral to help the general public understand the ways in which food can modify their brains.

A widespread knowledge that food interacts with the brain in ways similar to that of lethal, illegal drugs could change the way we eat. This idea is frightening for the food and beverage industry, which the Trib article points out, is worth at least one TRILLION dollars. Though there is overwhelming evidence for the addictive nature of certain foods, “food company executives and lobbyists say nothing has been proven.” Ha! We can only hope that one of these days, the CEO of Frito-Lay will wake up in a cold sweat, fiending for his next potato chip fix, and think to himself “What have I done!?” Until then, it’s important to understand that food isn’t just sustenance. It can also be viewed as a delicious, fatty, drug.

Read the original Star Tribune article here: http://www.startribune.com/lifestyle/wellness/133302438.html