Certain gene mutations associated with autism interfere with nervous-system signals that activate the same pathways as cannabis.

Some people with autism have a mutation or deletion in the neuronal gene neuroligin-3. But, although mice carrying a gene with the human mutation show autism-like behaviours, mice that lack the gene do not. Csaba Földy, Robert Malenka and Thomas Südhof at Stanford University in California have found that mutation, as well as deletion, of the gene changes how certain groups of neurons in the brain transmit signals. Signalling of a neuronal receptor that responds to cannabis and to endocannibinoids (which are made by the brain) is impaired in mice in which neuroligin-3 is mutated or missing. This suggests that disrupted endocannibinoid signalling contributes to autism, a mechanism that could suggest new strategies for treatment.

Neuron http://dx.doi.org/10.1016/j.neuron.2013.02.036 (2013)