How regions of the brain get their specificity

The cortex is divided into functionally distinct regions, and the layers of the visual cortex are a classic example. But how much do the intrinsic electrical properties of a particular neuron type vary from region to region? In a recent paper in J. Neurosci., Brandeis Neuroscience graduate students Mark Miller and Ben Okaty together with Prof. Sacha Nelson found a new region-specific firing type in Layer 5 pyramidal neurons. They argue that features as basic as membrane properties can be region-specific, and that this regional specialization of circuitry contributes to the determination of the region’s functional specialization.

Cell cycle checkpoint from the stringent response

E.coli cells exiting the stringent response

E.coli cells exiting the stringent response

The stringent response in E.coli is a response to nutrient (typically amino acid) starvation and is characterized by the accumulation of the small molecular regulator ppGpp, and a global response in transcriptional regulation.  In a new paper in PLoS Genetics, Daniel Ferullo and Susan Lovett examine chromosome segregation during the stringent respons and discuss what appears to be a novel G1-like cell cycle checkpoint in bacteria that occurs as the result.

Structural diversity of amyloid fibrils

Amyloid fibrils are associated with Alzheimer’s disease. In a recent study published in J. Mol. Biol., Nikolaus Grigorieff and coworkers used electron cyro-microscopy to study these structures and show that these fibrils coexisting in solution can be extremely polymorphic.

Rise and shine, little fly

Most animals sleep, but why they sleep and how the brain generates sleep is mysterious. In a recent study published in Neuron, postdoc Katherine Parisky and colleagues use genetic tools to manipulate the activity of neurons that control sleep in flies. Their results demonstrate that in the fly sleep is generated by GABAergic inhibition of a small cluster of peptidergic neurons within the circadian clock. Flies carrying mutations in this peptide, PDF, or its receptor, are hypersomnolent, similar to human narcoleptics who have defective signaling by the peptide hypocretin/orexin. These results suggest that the circuit architecture used to control arousal is ancient.

See also:

Multiple loops in DNA-protein binding complexes

Recent results from the Gelles lab published in PLoS Biology show that lac repressor bound to DNA can form different loop structures and that there are rapid transitions between the structures.

Protected by Akismet
Blog with WordPress

Welcome Guest | Login (Brandeis Members Only)