Most of us have been prescribed antibiotics at some point in our lives. The simple reality of communal species, such as humans, is that bacteria will thrive on our need for social interaction, and thus antibiotics are a common occurrence in modern life. The growing problem of antibiotic resistant bacteria has gained a lot of attention, and rightly so, since widespread use of antibiotics has given rise to deadly strains like MRSA. Scientists across the globe are focusing on the interactions between bacteria and antibiotics to figure out how drugs are causing bacterial genomes to evolve.
But how does antibiotic use affect the people taking them? A study out of Japan made an interesting connection between antibiotic use and human behavior. Minocycline, a tetracycline, was shown to alter male behavior by reducing their risk to fall into the “honey trap” The “honey trap” is when males tend to trust a physically attractive female without evaluating her trustworthiness. Males who were not taking minocycline were found to be increasingly trusting of women as attractiveness of the women increased. Males on minocycline seemed to be immune to the females’ attractiveness; they did not become more trusting of more attractive women.
Since minocycline inhibits microglial activities, the role of these cells in behavior has been given further weight, but the reason for the behavioral effects of minocycline are not yet clear. The drug may be interacting with glutamate and dopamine neurotransmission, for example, or the suppression of microglial cells may reduce stress response. It may have effects on the amygdala, which is activated during judgments of trustworthiness in human faces and also appears to be one of the most affect regions during minocycline use.
It’s amazing how commonly prescribed drugs can have side effects that we are only now discovering. You can’t help but wonder how many decisions or actions or any type of behavior has been affected by antibiotics or some other commonly used drug, without the knowledge of the user!
Posted by Joseph Starrett(3)
All images used under creative commons license:
Antibiotics: Flickr user michaelll (http://www.flickr.com/photos/-mic-/754962309/Z)
Honey: Wikimedia (Commons http://commons.wikimedia.org/wiki/File:Runny_hunny.jpg)