Regulation of Kv7 (KCNQ) K+ channel open probability by phosphatidylinositol 4,5-bisphosphate. Li, Y. et al. J. Neurosci. 25, 9825?9835 (2005)
Voltage-gated Kv7 (KCNQ) channels regulate K+ currents, such as the M current. Li et al. used single-cell and whole-cell patch clamp techniques and biochemical analysis to show that Kv7 channel gating is highly sensitive to phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2) concentrations, with low levels being associated with M current suppression. Moreover, distinct Kv7 channels had differential affinities for PtdIns(4,5)P2, which was thought to reflect their different maximal opening probabilities.
Wnt signalling regulates adult hippocampal neurogenesis. Lie, D. -C. et al. Nature 437, 1370?1375 (2005)
In the adult mammalian CNS, new hippocampal neurons can be generated from neural stem cells in the subgranular zone of the hippocampal dentate gyrus. Lie and colleagues investigated the signals that regulate the proliferation and commitment to neuronal fate of adult hippocampal stem/progenitor cells. They found that inhibition of WNT signalling decreased neurogenesis from hippocampal stem/progenitor cells in vitro and abolished it in vivo. Moreover, overexpression of WNT3 enhanced neurogenesis in vitro and in vivo. Their data therefore indicate that WNT has a pivotal role in neurogenesis in the adult hippocampus.
Thinning of the cerebral cortex visualized in HIV/AIDS reflects CD4+ T lymphocyte decline. Thompson, P. M. et al. Proc. Natl Acad. Sci. USA 102, 15647?15652 (2005)
At least 40% of patients with AIDS suffer from neurological symptoms, but the profile of brain damage caused by HIV is poorly understood. Using high-resolution MRI brain scans, Thompson and colleagues created three-dimensional maps and showed that the primary sensory, motor and premotor cortices were 15% thinner in patients with AIDS. Cortical thinning was associated with the degree of immune suppression, as measured by blood levels of CD4+ T lymphocytes, and cognitive and motor deficits.
Retinal ganglion cell degeneration is topological but not cell type specific in DBA/2J mice. Jakobs, T. C. et al. J. Cell Biol. 171, 313?325 (2005)
Glaucoma is usually associated with increased intraocular pressure and results in slow, progressive cell loss in the retina. Jakobs and colleagues studied the neural changes that occurred during elevated intraocular pressure using a mouse model of inherited glaucoma (strain DBA/2J). They found that cell loss was not restricted to a particular type of ganglion cell, and regions of cell death have characteristic topological neuronal atrophy radiating from the optic nerve head in fan-shaped sectors.
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In Brief. Nat Rev Neurosci 6, 917 (2005). https://doi.org/10.1038/nrn1818