The guppy or million fish is an ovoviviparous freshwater fish from South America that lives in low-flow areas of rivers, lakes and ponds. It is well known in the aquarium world since its care does not offer great difficulties and it reproduces very easily.
New research now suggests that the active ingredient in two drugs used to treat attention deficit hyperactivity disorder (ADHD), such as Ritalin and Concerta, can be passed on to several generations of offspring .
From one month of age through adolescence and into adulthood, first-generation guppies were exposed to methylphenidate hydrochloride (MPH) through the water in which they lived. The researchers then compared their behavior with that of a control population exposed to untreated water and found that the males exposed to Ritalin were less cautious when placed in a new environment, compared to those who did not receive the drug.
The effect of the drug on fish behavior was only seen in males. The findings add to growing knowledge about paternal effects on offspring, as well as the ability of those effects to span multiple generations, of which even less is known.
Researchers say that the paternal effect of behavior change can be passed on to offspring through non-genetic modifications in the sperm of male ancestors exposed to Ritalin. These molecular changes that do not affect DNA are a potential mechanism for males to transmit information about their environment, including exposure to drugs or contaminants, to their future offspring.
According to Helen Rodd, a professor in the department of ecology and evolutionary biology:
In many species, including guppies, males do not interact with offspring beyond the contribution of sperm, so it was traditionally thought that paternal effects would be limited to species in which the parents provide some form of care to the offspring or other resources to mothers. As of now, most of the known animal examples of paternal effects and transgenerational effects (effects spanning multiple generations) come from rodents, so our findings add to the handful of studies that have found paternal and transgenerational effects in others. species, although the current mechanism remains unclear.
It has been suggested that Ritalin could cause transgenerational effects because MPH has been shown to affect the sperm of male rodents. Furthermore, paternal effects have been observed in descendants of rats exposed to drugs with a similar mode of action. Despite these concerns, the transgenerational effects of paternal MPH exposure in humans are unknown .