December 2, 2005

NEUROBIOLOGY: Dendritic Spines Don’t Go with the Flow
Neurons receive incoming signals through synapses at hundreds of lollipop-shaped dendritic spines. The strength of synaptic signals can change, which allows the brain to adapt in response to experience. A study led by Bernardo Sabatini and Brenda Bloodgood found that the thin necks of dendritic spines constrict or widen in response to different inputs, regulating the ability of molecules to flow from the spine into the cell body. This action, detailed in the Nov. 4 Science, could be a way that the spines control synaptic strength and give synapses some independence from the cell.

GENETICS: Lab Moves Genomic Testing into the Clinic
The fruits of genetics are moving into the clinic as diagnostic tools even before researchers have worked out the underlying biology of the disease. Based in part on findings by HMS researchers, the Laboratory for Molecular Medicine (LMM) has developed clinical genetic tests to help doctors identify people who are at risk for sudden cardiac death and to detect the few lung cancers responsive to new target therapies. In the clinic, these and other genetic tools may help give physicians and their patients early opportunities to intervene and attenuate disease, while researchers follow the genetic knowledge toward better understanding of disease processes and new therapies. Pictured here are Peter Verlander and Heidi Rehm of the LMM.

CELL BIOLOGY: Early Steps Discovered in Protein-making Process
Though cell division has traditionally been linked to the transcriptional apparatus, a growing body of research shows that translational regulation is also important for cell proliferation. Unfortunately, the molecular pathways linking growth stimuli and translation remain sketchy. In the Nov. 18 Cell, John Blenis and colleagues, including graduate student Marina Holz, fill in some of the details. They show that a spatial and temporal reorganization of proteins around eukaryotic initiation factor 3 (eIF3), a major component of the translation initiation complex, is triggered by mammalian target of rapamycin (mTOR), a protein that is activated by growth stimuli. The findings not only provide much better insight into the mechanism of translation regulation, but they could also help identify and treat some cancers, particularly those that seem responsive to mTOR inhibitors such as the anti-proliferative agent rapamycin.