Women who smoke cannabis during pregnancy may be putting their developing foetus in danger, revealed an experimental study involving mice.
The study conducted by the research team at the University of Aberdeen also stressed that some of the prescribed drugs, including some to treat obesity, could also have detrimental effects in the womb.
Focusing on the importance of molecules produced naturally in the brain and how certain nerve cells recognise and connect with each other, the research claimed that anything that disrupts this process, like cannabis smoking, could affect brain function.
The researchers said that the brain molecules called endocannabinoids behave in the same way as tetrahydrocannabinol (THC) from cannabis, and affect the same receptors and signalling systems in the brain.
However, they stressed that this signalling process should occur unhindered, so that the brain can develop normally.
"Our findings highlight that the integrity of this signalling system should be maintained and not disrupted if the brain is to develop normally," BBc quoted Prof Tibor Harkany, recruited to the University of Aberdeen as part of the Scottish Universities Life Sciences Alliance (Sulsa), as saying.
He added: "Anything that disrupts this process such as cannabis smoking or certain drugs that interfere with this signalling system could ultimately affect the brain's functionality."
"Our initial findings showed the importance of these naturally occurring molecules in guiding the growth and connections of nerve cells in the developing brain," said Jan Mulder, first author of the study and Alzheimer's Research Trust fellow at the University of Aberdeen's Institute of Medical Sciences.
He added: "Now we demonstrate the extent of this signalling system and that complex network of neurons - the backbones of higher cognitive functions - do not develop normally when endocannabinoid signalling is disturbed."
Cannabis is considered to be one of the most widely used drugs by women at reproductive age, and earlier studies have pointed out that babies born to mothers who took cannabis while they were pregnant, experienced problems with physical activity.
The new study is published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).