Because autism is such a diverse condition, researchers have long sought to identify common ground — including shared mechanistic routes to multiple forms of it. This year, scientists plotted several new points of convergence on that map, several of which involve shared functions among autism-linked genes: Some genes play a role in the early development of neurons, according to a study of frog embryos, whereas others seem to be important for the function of the brain’s glial cells, an analysis of gene expression in single brain cells showed.
A few autism-linked genes converge on the same cellular neighborhoods, with high activity levels in the brain’s anterodorsal thalamus; diminishing the genes’ activity there led to neuronal hyperexcitability and memory problems in mice, one study showed. And six mouse models of autism became more sociable after drug treatments that boost levels of the neurotransmitter serotonin, according to work that flags part of the brain’s social-reward system, the nucleus accumbens, as another point of convergence.
Zooming out further revealed that distinct forms of autism may share distinct activity signatures across the brain, according to scans from 16 mouse models. One signature — marked by a pattern of brain overconnectivity — arises from a surplus of synapses, mouse work suggests.
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