A small number of individuals with autism harbor mutations in genes encoding neuroligins and neurexins, cell adhesion proteins that facilitate neuronal communication across synapses. Tabuchi et al. (see the Perspective by Crawley) studied the functional consequences of one of these mutations, an R451C substitution in neuroligin-3, by introducing the mutant protein into mice. The mice displayed enhanced spatial learning skills but impaired social interactions, and these behavioral changes were accompanied by a selective increase in inhibitory synaptic transmission. Thus, alterations in the balance of excitatory and inhibitory synapses can affect learning, and such alterations may be a contributing factor in the pathogenesis of autism.
K. Tabuchi, J. Blundell, M. R. Etherton, R. E. Hammer, X. Liu, C. M. Powell, T. C. Südhof, A neuroligin-3 mutation implicated in autism increases inhibitory synaptic transmission in mice. Science 318, 71-76 (2007). [Abstract] [Full Text]