Nearly a decade ago, our lab created a genetic mouse model of Dravet Syndrome by mutating the same gene that causes the disorder in humans. And just like humans, mice have spontaneous seizures and exhibit autism-like behaviours. My colleagues and I used these mice to test whether CBD could treat not only seizures, but autism as well.
Autism is a human disorder, so how do you test autism in mice? Of course, there’ s no perfect test, but scientists can model certain common aspects of autistic behaviour such as preference to engage in social interaction along with the quality of that interaction. In one test, a mouse chooses between interacting with another mouse or an inanimate object. Generally, mice prefer spending time with the other mouse over the object. But autistic-like mice, such as our Dravet Syndrome mouse, are indifferent, and spend an equal amount of time interacting with the mouse as the object. We gave these mice CBD and the amount of time they spent interacting with the other mouse shot way up( notably, we only needed to give them 10-20 % of the anti-epileptic dose to achieve this effect). Looking at the quality of the social interactions, we found that our autistic-like mice tended to dart away from a social interaction and huddle in the corner of their testing box.
This escape can be thought of as social anxiety, perhaps because they’ re overcome by socially-related sensory stimuli. However, CBD reduced the frequency of these escapes and improved the quality of their social interaction. So in both of our measures of autistic-like social behaviour in mice, CBD improved performance.
To understand how CBD was treating autistic-like behaviour in our mice, we recorded the electrical signals in individual brain cells. We found that CBD increased brain inhibition and restored balance by blocking a brain receptor called GPR55, which affects how brain cells communicate with one another. GPR55 is one of CBD’ s many brain targets which makes it such a diverse therapeutic tool for treating everything from pain to autism.
Social behaviour in mice remains an imperfect model of ASD in humans. But as long as the federal government classifies cannabis alongside heroin as a Schedule I drug— a classification reserved for dangerous substances that have no accepted medical use— then it’ s unlikely that we ' ll see large-scale human trials of CBD and ASD in the United States anytime soon. So for now, we hold our breath as we await the results of Israel’ s clinical trial, but can sleep easier knowing that we’ re finding success … at least in mice.
https:// www. civilized. life / articles / cannabidioltreatment-for-autism-scientific-support /