Mice bearing the genetic defect that causes Timothy syndrome show many autism-like behaviors, and may also have enhanced cognitive abilities like those seen in a small number of people with autism, suggests a poster presented Sunday at the Society for Neuroscience annual meeting in San Diego.

Infection early in pregnancy is more harmful to the fetus than at later stages, triggering brain and behavioral changes in the offspring similar to those seen in people with schizophrenia, according to two mouse studies published in October. A third study suggests that exercise can mitigate some of these effects.

Mice missing a large protein at the junction between neurons show motor impairments, anxiety and increased social behaviors, according to a study in the American Journal of Psychiatry. The protein, postsynaptic density-95 or PSD-95, is part of a key molecular bridge connecting other proteins linked to autism.

Chemicals produced by their mother’s immune system in utero alter the size of several key brain regions in people with schizophrenia, enlarging chambers that store cerebrospinal fluids, and shrinking parts of the cortex involved in processing emotion and memory.

Genes responsible for Alzheimer’s disease and fragile X syndrome — a form of mental retardation linked to autism — may operate through the same pathway, according to a study published in The Journal of Neuroscience.

Individuals with autism have trouble perceiving the passage of time, and pairing sights and sounds that happen simultaneously, according to two new studies.

The protein missing in fragile X syndrome is necessary for the proper development of neural stem cells — self-renewing cells that can differentiate into more specialized types, including neurons — according to a paper published in the August issue of Human Molecular Genetics.

An imaging study widely interpreted as heralding a diagnostic brain scan for autism is more preliminary than popular media reports would indicate, according to experts familiar with the work.

Autism and intellectual disability often occur together, but in most cases that overlap is not genetic, according to a study of twin pairs published in the American Journal of Medical Genetics. Unraveling this link might help researchers pinpoint brain circuits involved in both conditions, and better understand the diversity of symptoms in the autism spectrum, experts say.

A decade of research on the biology of autism, combined with a steady rise in diagnoses, has finally piqued the pharmaceutical industry’s interest in developing drugs for the disorder. Preliminary data from one small clinical trial already show positive results, and results from several others are expected early this summer.