Males influence infant's brain before pregnancy

Males may play a positive role in the development of offspring's brain even before pregnancy starts, says a study.

The research found that female mice exposed to male pheromones gave birth to infants with greater mental ability.

"This is the first study to show that pheromone exposure exerts an influence across generations in mammals," said lead researcher Sachiko Koyama from Indiana University in the US.

"We found that male pheromones seem to influence the nutritional environment following birth, resulting in changes to the brain that could extend to future generations," she said.

Pheromones are chemical signals used to communicate between organisms of the same species.

The connection between male pheromones and offspring's brain development seems to stem from the influence of male pheromones on the nursing ability of mother mice.

The scientists measured greater mammary gland development in mice exposed to male pheromones a week after exposure, which may have led to greater volumes or improved quality of milk production.

These mother mice also showed lengthier nursing periods compared to mice not exposed to the male pheromone.

To measure the intelligence of the offspring, the researchers placed mice in a water maze with a hidden platform.

The mice born of mothers exposed to male pheromones learned the location of the hidden platform much faster, suggesting quicker learning and stronger spatial memory compared to the control group.

A synthetic version of the male mouse pheromone called "SBT," was used in the study.

Although humans are not known to detect pheromones, power of scents has also been shown in humans through several studies.

The study was published in the journal Proceedings of the Royal Society of London B: Biological Sciences.