By REGINA PALATINI
Senior Staff Writer
For some individuals, a meal is not complete unless they consume some type of sweet, be it a cookie, cake, a doughnut or a candy bar. A recent study has shown that eating those sweets imprints a memory of that meal in our brains.
The hippocampus, that part of our brain whose job it is to form memories and then organize and store that information, connects emotions and senses like smell, taste and sound to memories. It transmits memories to the appropriate location in the cerebral hemisphere for long-term storage and subsequent retrieval, when necessary. Damage to the hippocampus can result in an inability to retain new memories.
The findings of the study, published in the journal Hippocampus, show that consuming sweets activates neurons in the dorsal hippocampus, the region vital for episodic memory. Episodic memory includes first-person events or past personal experiences that occurred at a particular place and time.
Interestingly, the “sweet” can consist of a natural sweetener such as sucrose or an artificial sweetener like saccharin. No difference was found when the results of using each of these sweets were compared.
The study found that when a meal of a sweetened solution was consumed, the expression of the synaptic plasticity marker, the activity-regulated cytoskeleton-associated protein, increased dramatically. The making of memories in our brains necessitates the process of synaptic plasticity.
“We think that episodic memory can be used to control eating behavior,” Marise Parent, professor in the Neuroscience Institute at Georgia State, said in a press release. “We make decisions like ‘I probably won’t eat now. I had a big breakfast.’ We make decisions based on our memory of what and when we ate.”
The possibility of controlling eating behavior using the hippocampus is based on the findings of the researchers’ previous studies, which illustrate that the temporary inactivation of the dorsal hippocampal neurons after a sucrose meal accelerates the onset of the next meal and causes the rat to eat more food.
In order to have a healthy diet, it is necessary for one’s brain to form a memory of one’s meals.
Research by a group of scientists in London revealed that the interruption of the encoding of the memory of a meal in humans, which could result from watching television or reading, for example, increases the amount of food consumption at the next meal.
People suffering from amnesia will eat again right after they are offered food, despite the fact that they have already consumed a meal, because they have no memory of the meal.
“To understand energy regulation and the causes of obesity, scientists must consider how the brain controls meal onset and frequency,” Parent said.
Other studies have found relations between obesity and increased snacking. Also, during the past 30 years, children and adults have been consuming more snacks on a daily basis, and they are consuming more of their daily caloric intake from those snacks.
Research by food scientists at Cornell University has found that a person’s emotional state affects his or her perception of taste. Sweets are the craving of choice for people in negative emotional states.
The Georgia State researchers plan to continue their research to determine whether a diet that is nutritionally balanced — one that contains protein, fat and carbohydrates — has a similar effect on Arc expression and whether this is required for the memory of sweet foods.
With findings like this, along with other studies in this area, we are beginning to understand how the brain controls the timing of meals and how memory influences energy intake.