Scientists Detect Pleasure Sensors Which Release Dopamine Neurotransmitters in Your Eyes

Scientists actually believe that the pleasure sensed when consuming good food, such as a decadent dish of chocolate ice cream, can be seen and even measured through the consumer's eyes with a low-cost ophthalmological tool.

Study researcher Dr. Jennifer Nasser, an associate professor in the department of Nutrition Sciences in Drexel University's College of Nursing and Health Profession's, lead a study by testing the use of electroretinography (ERG) to examine the number of increases in dopamine neurotransmitters found in retinas.

Background information regarding the study shows that dopamine is released when the optical nerve activates in response to light exposure through the eye's retina.

Nasser and colleagues used electrical signals in the retina that spiked high in response to a flash of light when a food stimulus was eaten by a participant. Nine participants were involved in the study and most of them were overweight, according to researchers. They were also all requested to fast for four hours prior to the test.

The results showed that each time a participant was given food, the drug stimuli were significantly greater than when a control substance (water) was ingested.

"What makes this so exciting is that the eye's dopamine system was considered separate from the rest of the brain's dopamine system," Nasser said, according to a press release. "So most people- and indeed many retinography experts told me this- would say that tasting a food that stimulates the brain's dopamine system wouldn't have an effect on the eye's dopamine system."

The validation of this tecnique through this and additional studies could help address new treatment for food addiction and food science, according to Nasser. 

"My research takes a pharmacology approach to the brain's response to food," Nasser said, according to the study. "Food is both a nutrient delivery system and a pleasure delivery system, and a 'side effect' is excess calories. I want to maximize the pleasure and nutritional value of food but minimize the side effects. We need more user-friendly tools to do that."

Further findings for the study can be found in the journal Obesity.