By giving mice access to sex, drugs, and their favorite foods, researchers say they've found a way around the need for daily medications.
In a remarkable experiment published today in Proceedings of the National Academy of Sciences, scientists injected mice with a cell containing a synthetic medication that lowers blood pressure. When the mice had sex or were given amphetamines or good food, their brains released dopamine, prompting the cell to release the anti-hypertensive peptide.
Martin Fussenegger, of the department of biosystems and engineering at the Swiss Federal Institute of Technology, explained that the designer cells housed in a seaweed gelatin were implanted into the guts of mice suffering from high blood pressure. Their natural dopamine systems did the rest.
“Certain activities, such as great food and sex, make us feel happy. This is the way our brain tells us and the rest of the body to repeat these activities over and over again since they are important for the individual and the entire species,” Fussenegger told Healthline.
Even though sex and certain drugs can elevate a person's blood pressure, mice with the cell implant had normal blood pressure levels during these activities.
“Amphetamines and sex may increase blood pressure. However, our circuit is so powerful that it even levels these blood pressure peaks that become dangerous for these patients,” Fussenegger said. “What it will feel like having sex with lower blood pressure, I do not know. In any case, blood pressure is just a model disease, and a very challenging one to treat. That is why we chose it. But the dopamine sensor and happiness could be used to treat other metabolic disorders.”
'Completely Novel' Treatment for Chronic Conditions
“Having [cell implants] controlled by the unconscious is a completely novel treatment strategy,” Fussenegger said. “We are looking for a joint venture with partners that will drive this technology into the clinics.”
John Salamone, a psychology professor at the University of Connecticut who has also researched the brain's dopamine system, said the techniques used in the recent study were "truly fascinating." Still, the authors present a limited view of the functions of dopamine neurons, he told Healthline.
"For example, [dopamine] neurons also respond to stressful or aversive conditions," Salamone said. "In addition, in the context of motivated behavior, there are experiments showing that [dopamine] neurons are more active during the anticipatory or instrumental phase of the task. One cannot simply assume that every time dopamine neurons respond, it is because of the impact of a primary reinforcing stimulus such as food or sex."
He said that while his observations complicate the interpretation of Fussenegger's experiments, they also open up new possibilities for the impact of his work. Replacing daily medications with a one-time implant may be years away, but would undoubtedly change the lives of patients for the better.
Image courtesy of freedigitalphotos.net.