Video Buzz | Glia Streaming Video You Should be Watching

December 10th

Brain metabolism dictates the polarity of astrocyte control over arterioles : Abstract : Nature: The ability of astrocytes to induce vasodilations over vasoconstricti ons relies on the metabolic state. This seems to turn out to be more complicated to interpret BOLD signals...
Neuroscience: Brain power : Article : Nature: A nice review about Gordon et al. who find that the prevailing oxygen level is a key determinant of whether astrocytes increase or decrease blood flow.

December 5th

December 4th

Astroglial Metabolic Networks Sustain Hippocampal Synaptic Transmission -- Rouach et al. 322 (5907): 1551 -- Science: The gap-junction subunit proteins connexin 43 and 30 allow intercellular trafficking of glucose and its metabolites through astroglial networks. This trafficking is regulated by glutamatergic synaptic activity mediated by AMPA receptors. In the absence of extracellular glucose, the delivery of glucose or lactate to astrocytes sustains glutamatergic synaptic transmission and epileptiform activity only when they are connected by gap junctions. These results indicate that astroglial gap junctions provide an activity-depen dent intercellular pathway for the delivery of energetic metabolites from blood vessels to distal neurons.

November 7th

November 5th

Deric Bownds' MindBlog: Does absolute brain size matter?: "A review by Marino of an article by Sherwood et al. in PNAS suggests that in ignoring absolute brain size we may have thrown out the baby with the bath water. [...] They indeed find that the human frontal cortex displays a higher ratio of glia to neurons than in other primates. However, and importantly, this relative difference is predicted by the allometric scaling inherent in the enlargement of the human brain. In other words, overall or absolute brain size constitutes a key factor in the ratio of glia to neurons. The authors suggest that the greater numbers of glia in the human neocortex may be due to the increased energetic costs of larger dendritic arbors and longer fiber projections within the context of the large human brain. The bottom line is that the human brain conforms to the general mammalian pattern of higher glia?neuron ratios with larger brains."

October 31st

Glia Are Essential for Sensory Organ Function in C. elegans -- Bacaj et al. 322 (5902): 744 -- Science: The researchers found that glia-ablated worms exhibit profound sensory deficits and that glia provide activities that affect neuronal morphology, behavior generation, and neuronal uptake of lipophilic dyes. To understand the molecular bases of these activities, they identified 298 genes whose messenger RNAs are glia-enriched. One gene, fig-1, encodes a labile protein with conserved thrombospondin TSP1 domains. FIG-1 protein functions extracellularl y, is essential for neuronal dye uptake, and also affects behavior.
NEUROSCIENCE: A New Glance at Glia -- Reichenbach and Pannicke 322 (5902): 693 -- Science: Bacaj et al demonstrate that neurons in the major sensory organ of the worms suvive the elimination of glia but display functional deficits.

October 22nd

October 16th

Effect of subchronic treatment of memantine, galan...[J Pharmacol Exp Ther. 2006] - PubMed Result: In Tg2576 mice (mutant APP expressing, APPswe).. nicotine compared to saline reduced guanidinum-sol uable amyloid-beta levels by 46-66%, left intracellular amyloid-beta levels unchanged, reduced glial fibrillary acidic protein immunoreactive astrocytes around the plaques, increased synaptophysin, and increased alpha7 nicotinic acetylcholine receptors in the cortex. Galantamine increased cortical levels of synapsophysin. Memantine reduced the total cortical levels of membrane-bound amyloid precursor protein (45-55%) in transgenic and non-transgenic mice.

September 24th

Neuroscience: An ageing view of myelin repair : Article : Nature: Shen et al in Nature Neuroscience show that, at lease in part, altered epigenetic regulation of gene expression might be reason why , in older animals, myelin repair is far less efficient than in younger mice with the same degree of demyelination.

September 12th