New findings by the scientists have raised the possibility of designing a cannabis drug in the future that can treat pain and seizures without causing memory loss.
Marijuana is commonly used for pain relief in many US states, but has regrettable side-effects such as making you forgetful.
Now scientists have pinpointed the part of the brain where the drug hinders working memory and discovered it is a separate area to where it has a medicinal effect.
They say the findings raise the possibility that they could design a cannabis drug that is able to treat pain and seizures without hurting the memory.
The team, led by Giovanni Marsciano from the French biomedical institution INSERM, found that marijuana eased pain via the neurons in the brain.
In a study on mice, the researchers looked at how their brain cell receptors reacted to the main psychoactive ingredient (THC), found in marijuana.