MedWorm provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest medical blog items that have been tagged with 'ion channels'. Sat, 03 Sep 2011 02:36:33 +0100 http://www.medworm.com/index.php?rid=2920353&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fwww.almaden.ibm.com%2Finstitute%2Fresources%2F2006%2FDisk2.avi We had read that Dr. Henry Markram of the Blue Brain project had given a talk at TED (technology, entertainment, design), but the video wasn’t released until this month.  This talk is geared towards a general audience, rather than getting into the specific details of the Blue Brain project, as he has before.  It is engaging and includes many suggestions towards the future of neuroscience and AI. Watch it online at the TED website. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=2920353 Thu, 22 Oct 2009 17:20:25 +0100 2920353 http://www.medworm.com/index.php?rid=2886207&cid=t_104637_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2009%2F10%2Finfluenza-m2-channel.html Viral ion channels have minimalist architecture. Despite their relatively simple structure, viral channels can achieve highly specific gating and selection of ions, and the particular mechanisms appear to be different from those of prokaryotes and eukaryotes. The unique structural and functional properties of viral channels make them ideal targets for antiviral therapy because the molecules that inhibit viral ion channels may not interact with human ion channels. The M2 proton channel of influenza A virus is a model viral ion channel. This small channel, whose pore is formed by four equivalent transmembrane helices, is the target of two widely used anti-influenza A drugs, amantadine and rimantadine, both belonging to the adamantane class of compounds. However, resistance of influenza A to ... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=2886207 Mon, 12 Oct 2009 15:42:00 +0100 2886207 http://www.medworm.com/index.php?rid=2667549&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F08%2F03%2Finert-designer-ligand-receptor-for-genetically-targeted-activation%2F Recently, Alexander et al. published Remote Control of Neuronal Activity in Transgenic Mice Expressing Evolved G Protein-Coupled Receptors [Neuron Neurotechniques], in which they use directed evolution techniques to modify a muscarinic GPCR to selectively bind an orally-deliverable small molecule that is otherwise inert. Apparently, this is the first time a channel has been engineered such that is selective for a biologically inert molecule, providing specificity of action. (They compare their technology with the hyperpolarizing allatostatin receptor which can have off-target effects.) Because the channel is specified genetically and the drug circulates systemically, it is easier to activate large populations of neurons (viz. optogenetic methods which are constrained to neurons in the ligh... neurodudes blogs http://www.medworm.com/rss/comments.php?id=2667549 Tue, 04 Aug 2009 01:44:51 +0100 2667549 http://www.medworm.com/index.php?rid=2405720&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F05%2F10%2Fsunday-afternoon-reading-genetic-tools-primer%2F I came across this fantastic review of tools for the Genetic Dissection of Neural Circuits in Neuron a few days ago. It’s by Liqun Luo, Ed Callaway, and Karel Svoboda. I highly recommend it, as it spans the gamut from genetic targeting (recombination, binary logic, viral delivery) to circuit reconstruction (super resolution LM, EM, brainbow) to activity modulation and functional mapping (uncaging, artificial GPCRs, light-gated channels, MIST). I don’t think I’ve ever seen quite a review of so many cutting edge neurotechnologies in one place. I can’t recommend this piece enough really. For me, with my lack of molecular expertise, the first sections on combinatorial gene targeting/expression techniques were great, pulling together Gal4, Cre/Flp, and Tet systems into a... neurodudes blogs http://www.medworm.com/rss/comments.php?id=2405720 Sun, 10 May 2009 22:04:56 +0100 2405720 http://www.medworm.com/index.php?rid=2232622&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F03%2F03%2Fneuroengineering-in-wired%2F Rewiring the Brain: Inside the New Science of Neuroengineering. Interviews Boyden and Deisseroth. Follow the link a video of an optogenetically controlled mouse. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=2232622 Tue, 03 Mar 2009 04:27:15 +0100 2232622 http://www.medworm.com/index.php?rid=2210494&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F02%2F24%2Fdeisseroth-on-new-step-chr2%2F Nature methods has a small piece interviewing Karl Deisseroth on properties of the new step ChR2. Some shortcomings of step ChR2 and future research directions: Deisseroth expects ongoing efforts to improve key features of these channels. “One disadvantage is that some of the mutants have reduced current compared to wild type, so multiple mutations may help to bring those current levels back up to wild-type levels,” he says. Projects designed to improve membrane targeting and to apply a composite of opsins, including the red light–responsive channelrhodopsin from Volvox carteri, are also in the works in his laboratory. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=2210494 Tue, 24 Feb 2009 17:01:18 +0100 2210494 http://www.medworm.com/index.php?rid=2149626&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F01%2F31%2Fscracm-chr2-circuit-mapping%2F As has become a hallmark of the Svoboda lab, this new paper in Nature (advance online publication) combines several cutting edge technologies (rAAV-delivered ChR2, most prominently, and 2-photon stimulation) to do some interesting synaptic physiology. The subcellular organization of neocortical excitatory connections : Article : Nature. They used ChR2 (with TTX and 4-AP to block action potentials) to find where on the dendritic tree particular inputs synapsed onto L3 and L5 cells and to measure the strength of those inputs. ChR2 depolarizes the input axon locally (60um spot diameter) at points of (potential) axodendritic contact. If you’ve heard the term “potential synapse” before, then think of this technique as a way of checking potential synapses and seeing if there re... neurodudes blogs http://www.medworm.com/rss/comments.php?id=2149626 Sun, 01 Feb 2009 02:40:17 +0100 2149626 http://www.medworm.com/index.php?rid=2095863&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F01%2F12%2Fbistable-current-photoswitches-in-neurons%2F Bi-stable neural state switches : Article : Nature Neuroscience Another channelrhodopsin breakthrough from Deisseroth’s lab. This time light is not required to keep the channel open. Light merely triggers opening and closing behavior. Blue-shifted light opens channels and red-shifted light closes them. This looks like another potentially powerful neurotechnology for interrogating circuits and systems. Relevant fig: (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=2095863 Mon, 12 Jan 2009 05:01:13 +0100 2095863 http://www.medworm.com/index.php?rid=1856044&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2008%2F10%2F06%2Fadaptive-binning-in-the-retina%2F The Circadian Clock in the Retina Controls Rod-Cone Coupling (Christophe Ribelayga, Yu Cao, and Stuart C. Mangel) An amazing paper from Neuron demonstrating adaptive (circadian clock-governed) binning in the retina, based on dopamine modulation of gap junction (electrical) synapses between retinal photodetectors. During the day, abundant dopamine release weakens gap junctions coupling rods and cones together so that visual acuity is high. When light is scarce (at night), there is less dopamine and the electrical coupling between rods and cones is increased. This is analogous to on-chip binning in CCD (digital) cameras. Binning increases signal (in light-limited systems, eg. seeing at night) by increasing optical input area and by reducing single element noise (ie. noise at different pho... neurodudes blogs http://www.medworm.com/rss/comments.php?id=1856044 Mon, 06 Oct 2008 21:00:15 +0100 1856044 http://www.medworm.com/index.php?rid=1713933&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2008%2F08%2F18%2Fneuroengineering-mosquito-repellents%2F There has been a few articles recently in the NYT about the neural mechanisms used by mosquito repellents. What a wonderful idea: Do some ephys recordings to find which neurons are sensitive to DEET (the current standard for mosquito repellents, which I can attest both doesn’t work very well and eats holes in synthetic clothing) and then build targeted compounds for those receptors/neurons/pathways. I always like this type of simple and practical neuroengineering. Right now, it appears that there’s a bit of controversy in the field. Earlier this year, in Science, a group from Rockefeller found that DEET masked sensitivity to human odors by interfering with a particular odorant receptor. This impressive result was recently question by entomologists from UC-Davis in a PNAS paper ... neurodudes blogs http://www.medworm.com/rss/comments.php?id=1713933 Tue, 19 Aug 2008 03:05:07 +0100 1713933 http://www.medworm.com/index.php?rid=1340808&cid=t_104637_111_f&fid=36048&url=http%3A%2F%2Ffeeds.b5media.com%2F%7Er%2Fb5media%2FAHeartyLife%2F%7E3%2F261962624%2F As many as 1000 deaths each year are associated with long QT syndrome. This very scary cardiac arrhythmia puts teen and young persons at risk for sudden cardiac arrest, usually ending in death. These same young ladies and gents have healthy hearts otherwise. Researchers have found that a drug that is used in cases of angina can safely help to treat QT syndrome… In the current, pilot study, researchers found that a drug, ranolazine (brand name Ranexa, CV Therapeutics) shortens the QT interval by about 5 percent; just enough to reduce symptoms and risks associated with one form of LQTS (LQT3-deltaKPQ) What happens in long QT syndrome? Changes to ion channels cause channel proteins to leak charged particles which alters the timing of the heartbeat. Isn’t it really crazy how our b... A Hearty Life blogs http://www.medworm.com/rss/comments.php?id=1340808 Tue, 01 Apr 2008 13:36:17 +0100 1340808 http://www.medworm.com/index.php?rid=1090451&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2007%2F12%2F12%2Fwhere-are-we-with-this-whole-free-will-thing%2F Haim Sompolinsky has written an excellent book chapter on the scientific view of free will and choice, pulling in good ideas from physics and neuroscience along with contemporary philosophical commentary. I think this chapter might be helpful for neuroscientists outside of the lab. Often a dinner table discussion has moved to the idea of “quantum consciousness” or “quantum free will”. Often, someone will mention Roger Penrose, who has become something of a poster boy for this idea that quantum indeterminacy (eg. Heisenberg’s uncertainty principle) is one possible way that free will is really free. And then, people look around and say, “Well, you’re a neuroscientist. Do we have free will?” (And that’s when I take another big drink or bi... neurodudes blogs http://www.medworm.com/rss/comments.php?id=1090451 Wed, 12 Dec 2007 14:31:43 +0100 1090451 http://www.medworm.com/index.php?rid=1027083&cid=t_104637_122_f&fid=34755&url=http%3A%2F%2Fneuropsychological.blogspot.com%2F2007%2F11%2Fnews-about-ion-channels.html A press release from the NIH:Scientists Zero in on the Cellular Machinery that Enables Neurons to FireIf you ever had a set of Micronauts — toy robots with removable body parts — you probably had fun swapping their heads, imagining how it would affect their behavior. Scientists supported by the National Institutes of Health have been performing similar experiments on ion channels — pores in our nerve cells — to sort out the channels' key functional parts.In the November 15 issue of Nature, one group of researchers shows that a part of ion channels called the paddle is uniquely transplantable between different channels. Writing in the same issue, another group exploited this property to probe the three-dimensional structure of ion channels on an atomic scale."The effects of many tox... BrainBlog blogs http://www.medworm.com/rss/comments.php?id=1027083 Wed, 14 Nov 2007 20:18:00 +0100 1027083 http://www.medworm.com/index.php?rid=522932&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2007%2F04%2F05%2Fmore-halorhodopsin%2F This week’s Nature has quite a few additional halorhodopsin articles for photochannel fans. Halorhodopsin article from Deisseroth’s lab: Multimodal fast optical interrogation of neural circuitry [News & Views] Also, there is an intriguing article on both the general excitement in the neuroscience community with this new technology and a possible intellectual property dispute over it. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=522932 Thu, 05 Apr 2007 05:48:47 +0100 522932 http://www.medworm.com/index.php?rid=486192&cid=t_104637_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2007%2F03%2F09%2Foptical-silencing-cl-channel%2F Ed strikes again! Two-Color, Bi-Directional Optical Voltage Control of Genetically-Targeted Neurons Having found a powerful method for activating neurons with blue light in the protein Channelrhodopsin-2 (ChR2) [1], we sought to augment the toolbox by finding a single-component system capable of mediating light-elicited neuronal inhibition. We identified a powerful tool, the mammalian codon-optimized version of the light-driven chloride pump halorhodopsin, from the archaebacterium Natronobacterium pharaonis (here abbreviated Halo) [2]. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=486192 Sat, 10 Mar 2007 04:40:56 +0100 486192