Science Today

Although many mental illnesses are uniquely human, animals sometimes exhibit abnormal behaviors similar to those seen in humans with psychological disorders. Such behaviors are called endophenotypes. Now, researchers at the California Institute of Technology (Caltech) have found that mice lacking a gene that encodes a particular protein found in the synapses of the brain display a number of endophenotypes associated with schizophrenia and autism spectrum disorders. The new findings appear in a recent issue of The Journal of Neuroscience, with Mary Kennedy, the Allen and Lenabelle Davis Professor of Biology at Caltech, as the senior author. The team created mutations in mice so that they were missing the gene for a protein called densin-180, which is abundant in the synapses of the brain, those electro-chemical connections between one neuron and another that enable the formation of networks between the brain's neurons. This protein sticks to and binds together several other protei...

Johns Hopkins researchers have found a likely explanation for the slow growth of the most common childhood brain tumor, pilocytic astrocytoma. Using tests on a new cell-based model of the tumor, they concluded that the initial process of tumor formation switches on a growth-braking tumor-suppressor gene, in a process similar to that seen in skin moles. The findings, published in the June 1 issue of Clinical Cancer Research, could lead to better ways of evaluating and treating pilocytic astrocytomas. "These tumors are slow-growing to start with, and sometimes stop growing, and now we have a pretty good idea of why that happens," says Charles G. Eberhart, M.D., Ph.D., associate professor of Pathology, Ophthalmology and Oncology at Johns Hopkins. "These tumors also can suddenly become more aggressive, which we now think represents an inactivation of this tumor-suppressor gene, and this inactivity could be used as a marker to determine which patients need more therapy....