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An analysis of four mouse models negates certain assumptions underlying the “signaling imbalance theory,” a popular hypothesis about autism’s origins in the brain. The findings suggest that the imbalance is a compensatory response to other problems in the brain, rather than the underlying cause of autism.
The signaling imbalance theory holds that the brains of autistic people have too much excitatory brain activity and not enough inhibitory signals to counteract it. This imbalance then causes neurons to fire too often, the theory goes, and contributes to motor problems, sensory hypersensitivity and other autism traits.
This hypothesis, first suggested in 2003, is so popular that it is often cited as fact.
The new study questions its underlying assumptions, however. The researchers did find a skewed signaling balance but not the unusually high rate of neuronal firing, or “spikes.”
“It’s not as straightforward as the classic hypothesis is ...
