Blocking the expression of the MeCP2 gene decreases the number of synapses, the junctions between neurons. It also prevents synapses from scaling up their activity to make up for the loss, according to unpublished data shown yesterday at the Society for Neuroscience annual meeting in San Diego.

UBE3A, a protein mutated in Angelman syndrome and autism, regulates communication between neurons in the brain, according to a study published 29 October in Cell.

A new mouse model for Rett syndrome shows that disrupting a single brain messenger can produce nearly all of the characteristic features of the syndrome, researchers report today in Nature.

Most inhibitory neurons respond in the same way to a range of visual stimulation, but a subset of them may be tuned in to specific signals, suggest two reports published in September in Neuron.

The amygdala, a brain region that regulates fear and anxiety, shows abnormal neuronal signaling in a mouse model of fragile X syndrome, according to two studies published this summer. These are the first to explore cellular defects in the region in fragile X.

Researchers have uncovered an important molecular piece of a learning mechanism that occurs at the junction between neurons. The findings, which may help understand how the brain is disrupted in disorders such as autism, appear in the 24 June issue of Neuron.

Scientists have discovered that neurexins — proteins linked to autism — bind to a wide variety of molecules at the junction between neurons. In this complicated system, the breakdown of any one of the parts could lead to improper cell signaling, ultimately giving rise to disease.

Researchers are tinkering with mouse models to investigate the function of a protein that helps wire neurons together and that has repeatedly been linked to autism. Three such reports of the protein, neuroligin-1, have appeared this year.

Two independent teams have discovered key molecular steps in the way a single gene disrupts the connections between neurons in individuals with Angelman syndrome. Because the gene, UBE3A, has also been linked to autism, the findings could help scientists understand and treat a range of neurodevelopmental disorders.

Researchers have found a higher density of several types of interneurons — nerve cells that connect sensory and motor neurons in the brain— in postmortem brain tissue from individuals with autism, compared with healthy controls. The findings appear in the February issue of Acta Neurologica Scandinavica.