The study suggests that anti-obesity drugs that work by blocking brain molecules similar to those in marijuana could also interfere with mental development in young children.

Marijuana known to be an appetite stimulant is also used in new class of anti-obesity drugs.

Derived from the plant Cannabis sativa, it contains special active compounds collectively known as cannabinoids. But other cannabinoids (endocannabinoids) are generated naturally inside the body.

The study conducted over mice showed that blocking cannabinoid receptors could also suppress the adaptive rewiring of the brain necessary for neural development in children.

"Our finding of a profound disruption of cortical plasticity in juvenile mice suggests caution is advised in the use of such compounds in children," said Mark F. Bear, lead author and director of the Picower Institute and Picower Professor of Neuroscience.

The researchers studied plasticity, the brain's ability to change in response to experience, by temporarily depriving newborn mice of vision in one eye soon after birth.

This experiment induced long-lasting loss of synapses that causes blindness in the covered eye, while synapses shift to the uncovered eye. How and where this synaptic shift occurs in the primary visual cortex has remained controversial.

Bear said that it is necessary to understanding the mechanism behind this phenomenon because the same brain mechanisms are used for normal development and may cause developmental delays in humans.