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  • July 14, 2014
  • 02:27 PM
  • 51 views

History of neuroscience: Hodgkin and Huxley

by neurosci in Neuroscientifically Challenged







Hodgkin and Huxley used the large axons of the giant squid to measure voltage changes during an action potential.






By the late 1930s, researchers had come to understand several important things about the conduction of signals within neurons. For example, they knew that signaling within neurons is electrical in nature (as opposed to signaling between neurons, which is usually chemical), and that it occurs in bursts of activity called action potentials. And they knew that action potentials are stimulated by the movement of sodium ions across the neuronal membrane through proteins called ion channels. But the exact details of what is going on during an action potential were not made fully clear until Alan Hodgkin and Andrew Huxley started collaborating on the issue in 1939.What is an action potential?To understand Hodgkin and Huxley's findings, it helps to have some background on what happens during an action potential. When a neuron is at rest, there are a variety of charged particles called ions that are unevenly distributed inside and outside of the cell. Ions are simply atoms that have either gained or lost an electron; this gain or loss of electrons gives the atoms a negative or positive overall charge, respectively. When a neuron isn't excited, positively-charged sodium ions accumulate outside of the neuron, while positively-charged potassium ions accumulate inside. There are also negatively-charged chloride ions and organic ions that accumulate outside and inside the cell, respectively. A number of mechanisms, including both passive (e.g. diffusion) and active (e.g. the Na-K pump) processes, work to create a unequal balance of positively- and negatively-charged particles between the inside and outside of the neuron. This difference in charge is known as the resting membrane potential; typically in neurons it is around -65 to -70 mV, which means that the inside of the neuron is negatively-charged with respect to the outside.During an action potential, the membrane potential rapidly changes. By Hodgkin and Huxley's time it was already suspected that this rapid change was produced by the movement of positively-charged sodium ions from the outside to the inside of a neuron through ion channels. The influx of positively-charged particles was thought to be the basis for the burst of electrical energy that then proceeded to travel down the neuron as an action potential. However, the extent of the change in membrane potential wasn't known, and the exact role of the different types of ions found in the intracellular and extracellular fluid of neurons had yet to be elucidated.Voltage clamps and giant squid axonsOne of the difficulties in understanding action potentials before Hodgkin and Huxley's work was that neurons are incredibly small. (At their largest they are about 100 micrometers, but they can be under 10 micrometers. By comparison, a human hair is about 80 micrometers.) Scientists found that the size of the axons in most species made it difficult or impossible to insert a recording device to measure voltage changes during an action potential.Hodgkin and Huxley got around this problem by studying action potentials in the relatively enormous axons (up to 1 mm in diameter) of the giant squid. They inserted a fine capillary electrode into the giant squid axon and were able to measure electrical changes within the axon during an action potential. They found that the membrane potential of the neuron actually reversed during an action potential, causing the neuron to momentarily have a positive membrane potential. This rapid reversal of membrane potential was the impetus for the generation of the electrical signal underlying the action potential.Hodgkin and Huxley also utilized an innovative tool that allowed them to determine the contribution of different ions to the change in membrane potential seen during an action potential. The device, called a voltage clamp, uses electrical stimulation and feedback to set the membrane potential of a neuron at a particular voltage and keep it there. Previous attempts to gauge the exact contribution of different ions to the action potential were stymied by the voltage-dependency of the ion channels involved. Voltage-dependent ion channels open and close when the membrane potential reaches a particular voltage. Thus, because the action potential involves rapid changes in membrane potential, it also involves rapid fluctuations in the opening and closing of ion channels. This happens so quickly that researchers before Hodgkin and Huxley were unable to slow it down enough to get an understanding of what was going on. By using a voltage clamp, Hodgkin and Huxley essentially were able to "freeze" the neuron at particular voltages, which allowed them to gather details on what was happening in the neuron at each stage in the action potential.Hodgkin and Huxley used the voltage clamp while also manipulating the levels of different ions in the extracellular fluid. In this way they were able to determine the exact contribution of sodium and potassium (and chloride and organic) ions to the action potential. They determined that an influx of sodium ions through voltage-gated sodium ion channels causes a rapid shift in membrane potential, which causes the initiation of the electrical signal that is known as the action potential. Immediately after this change in membrane potential, however, ion channels open that allow potassium ions to flow out of the neuron. This helps the membrane potential to return to its normal level.Hodgkin and Huxley's work for the first time allowed researchers a step-by-step view of the processes involved in an action potential. Their findings caused interest in electrophysiology to skyrocket, eventually inspiring the development of a more precise form of the voltage clamp known as the patch clamp, which allows for the measurement of current across single ion channels. Perhaps most importantly, however, Hodgkin and Huxley's successful efforts at precisely modeling the action potential would lay the groundwork for a more quantitative approach to biology in the twentieth century.Schwiening, C. (2012). A brief historical perspective: Hodgkin and Huxley The Journal of Physiology, 590 (11), 2571-2575 DOI: 10.1113/jphysiol.2012.230458... Read more »

  • July 14, 2014
  • 01:13 PM
  • 78 views

Schizophrenic Noise and Schizophrenic Voices

by Gabriel in Lunatic Laboratories

Hear that voice? What is there more than one? Is this real, or fake? How do you know? That is how schizophrenia works: auditory hallucinations, confusion, inability to tell what […]... Read more »

Teal S. Eich,, Derek Evan Nee,, Catherine Insel,, Chara Malapani,, & Edward E. Smith. (2014) Neural Correlates of Impaired Cognitive Control over Working Memory in Schizophrenia. Biological psychiatry, 76(2). info:/10.1016/j.biopsych.2013.09.032

  • July 14, 2014
  • 01:00 PM
  • 42 views

16 Ancient Clovis Elephant-Hunting Camp Discovered in Mexico

by Blake de Pastino in Western Digs

Archaeologists in Mexico have discovered an ancient camp where members of the Clovis culture hunted an elephant-like animal never before seen in North America's archaeological record. What’s more, the site dates to 13,400 years ago, making it one of the oldest known Clovis sites, and the southernmost evidence yet found of the culture's reach. Read on to find out more!... Read more »

Sanchez, G., Holliday, V., Gaines, E., Arroyo-Cabrales, J., Martinez-Taguena, N., Kowler, A., Lange, T., Hodgins, G., Mentzer, S., & Sanchez-Morales, I. (2014) Human (Clovis)-gomphothere (Cuvieronius sp.) association  13,390 calibrated yBP in Sonora, Mexico. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1404546111  

  • July 14, 2014
  • 05:02 AM
  • 79 views

Joint hypermobility, gait and autism

by Paul Whiteley in Questioning Answers

I have already made mention of the paper by Maya Shetreat-Klein and colleagues [1] on this blog as part of a post on the potential usefulness of kata training for at least some people on the autism spectrum (see here). Based on an analysis of 38 children diagnosed with autism spectrum disorder (ASD) and a similar number of asymptomatic controls (all medication free), researchers set about recording "the characteristics of gait and prevalence of toe walking, the range of passive joint mobility, and age at walking" for their groups. They concluded that: "Children with ASDs had significantly greater joint mobility... more gait abnormalities... and on average walked 1.6 months later than their non-autistic peers". Ergo, much greater research focus should be directed to motor issues in cases of autism.The cliff walk @ Wikipedia A few further details from the study might be useful:The analysis of movement such as gait and mobility is a science which I won't even pretend to understand. You get terms like goniometer fulcrum which probably makes a lot of sense to those in the know, but to me just sounds like a character from Game of Thrones. Suffice to say however that various measures were used to ascertain passive joint mobility - that is suppleness - across fingers, wrist, elbow and ankle. Gait was also analysed based on participants being "videotaped while walking and running barefoot up and down a hallway in the physician's office for 1-2 min".Results: as a group, participants with autism showed significantly greater values for maximum passive joint mobility angles across nearly all measured joints than controls. Taking one example, finger extension (or should that be 'finger metacarpo-phalangeal joint extension angle'), the authors present the very stark differences in angles obtained in histogram form between ASD and control participants. The majority of those with autism able to extend 110 degrees or over; such a feat only noted in 1 of the control participants. I might direct you to a post I wrote a while back on joint hypermobility (see here) which I'll talk about it moment.When it came to gait, the authors observed: "toe-walking was significantly more prevalent in children with autism" than controls (33% vs 3% observed on video only). I've talked about toe walking and autism in a previous post (see here) and what it may or may not mean for autism when present. Several other features of gait were also observed; 33% of children with autism were described as apraxic (an inability to execute learned purposeful movements) and 20% were described as clumsy. Both of these issues were not noted in any of the control group participants.I found the Shetreat-Klein paper to be quite an intriguing read. Not only for the results obtained but because nestled in the paper introduction was reference to some of the original descriptions of autism by Leo Kanner, and how he "commented on the motor deficits in many of his patients". I've talked previously on this blog about how the seminal 1943 paper from Kanner [2] contained so much more than just descriptions of the triad (now dyad) of behaviours which make up the clinical diagnosis of the condition (see here). Aspects which we have perhaps ignored for too long...The word 'hyptonia' - roughly translated as decreased or low muscle tone - is also a discussion point in the paper: "Our findings that passive joint mobility is on average increased in autism corroborates other studies that report a significantly increased proportion of clinically hypotonic children among those with ASD". Once again, I can't profess to be able to offer any great insight into this issue aside from some light reading around this concept and other uses in the research texts with autism in mind. Hypotonia seems to crop up quite a bit in various case reports detailing often rare genetic conditions with autism as part of presentation. Take for example the paper by Belengeanu and colleagues [3] reporting on a young child presenting with developmental delay and among other things, hypotonia. The paper by Shuvarikov and colleagues [4] talking about a potential HERV (human endogenous retrovirus) mediated genetic deletion with hypotonic features is another example; HERVs are another favourite talking point on this blog (see here).That all being said, I'd also like to go back to the previous mention of joint hypermobility. Shetreat-Klein et al do talk about whether the descriptions of hyptonia in cases of ASD, or at least "joints with ligamentous laxity", might suggest "a disorder of elastin or collagen". Collagen issues immediately brought my mind back to the condition called Ehlers-Danlos syndrome (EDS), a heritable disorder of connective tissue. One of the primary features of EDS - accepting that there are various different presentations - is hyper-flexible joints. The literature looking at any overlap between autism and EDS is currently sparse, very sparse. I did happen upon the paper by Takei and colleagues [5] (open-access here) detailing a single case where "autistic disorder and EDS were diagnosed" concurrently. Takei et al describe a family history of EDS and as they note: "We speculate that associations exist between connective tissue diseases and autistic disorders, and that connective tissue abnormalities may contribute to autistic symptoms". I do wonder whether this might be an area requiring a little more scientific inspection.The take home message from this post is that joint mobility and gait issues do seem to be quite apparent across the autism spectrum. Alongside other research in this area, one might start asking further questions about the hows and whys of such findings and whether it may offer further insight into some of the underlying issues potentially associated with at least some of the autisms?To close, football (soccer). Now knowing that Germany are the 2014 World Cup Champions and this is the first lifting of the Jules Rimet trophy in a reunified Germany, I'm sure David Hasselhoff might have something to say...----------[1] Shetreat-Klein M. et al. Abnormalities of joint mobility and gait in children with autism spectrum disorders. Brain Dev. 2014 Feb;36(2)... Read more »

  • July 13, 2014
  • 08:53 PM
  • 61 views

Photosynthesis in action: new technique resolves atomic changes in undamaged photosystems

by Jonathan Trinastic in Goodnight Earth

A new experimental technique allows scientists to see conformational changes in photosynthetic systems without damaging the samples!... Read more »

Kupitz, C., Basu, S., Grotjohann, I., Fromme, R., Zatsepin, N., Rendek, K., Hunter, M., Shoeman, R., White, T., Wang, D.... (2014) Serial time-resolved crystallography of photosystem II using a femtosecond X-ray laser. Nature. DOI: 10.1038/nature13453  

  • July 13, 2014
  • 03:15 PM
  • 87 views

New ways to test for Alzheimers

by Gabriel in Lunatic Laboratories

Accurately diagnosing alzheimer’s is not an easy thing to do. In fact most of the time people aren’t diagnosed until very late in the progression of the disease, long after […]... Read more »

Matthew E Growdon,, Aaron Schultz,, Alexander Dagley,, Rebecca Amariglio,, Trey Hedden,, Dorene M. Rentz,, Keith Johnson,, Reisa Sperling,, Mark W. Albers,, & Gad Marshall,. (2014) Olfactory identification and Alzheimer's disease biomarkers in clinically normal elderly. Nature Neuroscience. info:/

  • July 13, 2014
  • 05:21 AM
  • 6 views

Hotter, Smarter, Better Brains

by Viputheshwar Sitaraman in Draw Science

It is evident that (a) higher body temperature leads to higher brain performance and (b) the sames holds true in an evolutionary context in terms of brain size. So hotter = smarter?... Read more »

James F. Gillooly. (2013) Hotter is Smarter: The temperature-dependence of brain size in vertebrates. PeerJ. info:/10.7287/peerj.preprints.155v1

Wright KP Jr, Hull JT, & Czeisler CA. (2002) Relationship between alertness, performance, and body temperature in humans. American journal of physiology. Regulatory, integrative and comparative physiology, 283(6). PMID: 12388468  

  • July 12, 2014
  • 01:59 PM
  • 116 views

Infant once thought Cured of HIV tests Positive

by Gabriel in Lunatic Laboratories

I hate doing sad posts, it’s not my thing. But this is a big deal so I thought I would share it, the child known as the “Mississippi baby” – whom for […]... Read more »

Persaud, D., Gay, H., Ziemniak, C., Chen, Y., Piatak, M., Chun, T., Strain, M., Richman, D., & Luzuriaga, K. (2013) Absence of Detectable HIV-1 Viremia after Treatment Cessation in an Infant. New England Journal of Medicine, 369(19), 1828-1835. DOI: 10.1056/NEJMoa1302976  

  • July 12, 2014
  • 01:42 PM
  • 121 views

Media and the Mind: Emotional Contagion

by JBSheppard in Antisense Science

Facebook recently carried out an experiment to change the emotions of over 600,000 users through a known psychological process called "emotional contagion". ... Read more »

  • July 12, 2014
  • 11:36 AM
  • 103 views

Organic food: meta-analysed

by Paul Whiteley in Questioning Answers

A very quick post to direct you to the paper by Barański and colleagues [1] which is currently making a few headlines and sparking some debate (see here and see here) with their assertions: "the concentrations of a range of antioxidants such as polyphenolics were found to be substantially higher in organic crops/crop-based foods" and "the frequency of occurrence of pesticide residues was found to be four times higher in conventional crops, which also contained significantly higher concentrations of the toxic metal Cd [cadmium]".Lead by researchers based at Nafferton Farm affiliated to Newcastle University, the literature review and meta-analysis looked at over 300 studies looking at "the composition of crops and foods". According to the BBC website, Carlo Leifert who headed the review said: "This study demonstrates that choosing food produced according to organic standards can lead to increased intake of nutritionally desirable antioxidants and reduced exposure to toxic heavy metals".I've had the pleasure of visiting Nafferton Farm once or twice and chatting to Carlo and his team about some of the work going on. It is a lovely part of the world and some great science is being done and reported in the peer-reviewed press [2]. Appreciating that there are still some significant gaps in the science about organic vs. conventional farming methods and their impact on food in terms of yields and nutritional quality, I do think that this latest (and largest) review is something which should not be ignored...-----------[1] Barański M. et al. Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses. Br J Nutr. 2014 Jun 26:1-18.[2] Stergiadis S. et al. Improving the fatty acid profile of winter milk from housed cows with contrasting feeding regimes by oilseed supplementation. Food Chem. 2014 Dec 1;164:293-300.----------Barański M, Srednicka-Tober D, Volakakis N, Seal C, Sanderson R, Stewart GB, Benbrook C, Biavati B, Markellou E, Giotis C, Gromadzka-Ostrowska J, Rembiałkowska E, Skwarło-Sońta K, Tahvonen R, Janovská D, Niggli U, Nicot P, & Leifert C (2014). Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses. The British journal of nutrition, 1-18 PMID: 24968103... Read more »

  • July 11, 2014
  • 04:11 PM
  • 128 views

Antioxidants can accelerate Cancer, ya really!

by Gabriel in Lunatic Laboratories

Oxidative stress on the body caused by free radicals, billed as a bad thing. Fruits, veggies and just about anything with the word healthy in the title is “jam packed” […]... Read more »

Phimister, E., Chandel, N., & Tuveson, D. (2014) The Promise and Perils of Antioxidants for Cancer Patients. New England Journal of Medicine, 371(2), 177-178. DOI: 10.1056/NEJMcibr1405701  

  • July 11, 2014
  • 01:45 PM
  • 132 views

Change your Genes with Stem Cells!

by Gabriel in Lunatic Laboratories

So researchers for the first time were evaluating the safety and reliability of the existing targeted gene correction technologies and in the process they successfully developed a new method of gene […]... Read more »

  • July 11, 2014
  • 10:22 AM
  • 122 views

Ye Old Science Journal. Interesting articles from the premiere journal of 1880.

by The Lab Hippo in The Lab Hippo

One of the perks to my job is that I can get access to just about any journal article I want for free. I know, it sounds like a dream life, but hey you go to college for 10 years and you get some favors thrown your way. A few years ago Science scanned all their historical archives put them online, so I begun to peruse a few and was pleasantly amused. In what may become a recurring theme to the LabHippo, I now present to you some of the more entertaining articles. We begin with the first year Science was published, 1880, Volume 1, Issues 1-28.... Read more »

  • July 11, 2014
  • 10:21 AM
  • 109 views

Part 2. Epigenetics. Rat Tounges & Ham Sandwiches Can Influence Children

by The Lab Hippo in The Lab Hippo

Picture your parents having sex. No..no good, too weird? OK then, picture your grandparents having sex. Even weirder? Fine, picture your great-grandparents having sex. That one might not be as bad. Chances are you never met your great-grandparents, which makes them somewhat strangers to you. You had eight great-grandparents and though you might not even know their names, about 12.5 percent of your DNA was inherited from them. Now imagine your great-grandmother eating a ham sandwich while having sex with your great-grandfather. Could that ham sandwich somehow affect your great-grandmother’s DNA? Crazier still, could that ‘ham sandwich tainted DNA’ be passed down to the 12.5 percent that is now in you?... Read more »

Pembrey, M., Bygren, L., Kaati, G., Edvinsson, S., Northstone, K., Sjöström, M., & Golding, J. (2005) Sex-specific, male-line transgenerational responses in humans. European Journal of Human Genetics, 14(2), 159-166. DOI: 10.1038/sj.ejhg.5201538  

  • July 11, 2014
  • 10:19 AM
  • 112 views

Epigenetics. Rat Tounges & Ham Sandwiches Can Influence Children (Part 1)

by The Lab Hippo in The Lab Hippo

There’s a concept in biology that has begun to break into mainstream culture that makes the mishmosh of genetics even more complicated. It’s called ‘epigenetics’, and it can explain how our environment, such as what we eat and breath, can influence our DNA. Biologists have known about epigenetics for some time, but it seems to have gained widespread traction lately largely due to findings that a mother can influence her unborn child’s DNA during pregnancy. This is called ‘intergenerational epigenetics’, and again, scientists have known about it for a while. What’s an even newer and more controversial aspect to epigenetics is ‘transgenerational epigenetics’. This is the idea that our environment can influence our children’s and even our grandchildren’s DNA before they are even conceived. How can that be possible?... Read more »

Rönn T, Volkov P, Davegårdh C, Dayeh T, Hall E, Olsson AH, Nilsson E, Tornberg A, Dekker Nitert M, Eriksson KF.... (2013) A six months exercise intervention influences the genome-wide DNA methylation pattern in human adipose tissue. PLoS genetics, 9(6). PMID: 23825961  

Weaver, I., Cervoni, N., Champagne, F., D'Alessio, A., Sharma, S., Seckl, J., Dymov, S., Szyf, M., & Meaney, M. (2004) Epigenetic programming by maternal behavior. Nature Neuroscience, 7(8), 847-854. DOI: 10.1038/nn1276  

  • July 11, 2014
  • 10:15 AM
  • 91 views

Can antioxidants accelerate cancer growth? Why you shouldn’t smoke and drink Vitamin Water

by The Lab Hippo in The Lab Hippo

Recently a paper was published that showed adding antioxidants, such as vitamin E, to the diet of mice accelerated the growth of lung tumors. This finding contradicts the commonly held belief that antioxidants act to protect us from cancer and other diseases.... Read more »

Sayin VI, Ibrahim MX, Larsson E, Nilsson JA, Lindahl P, & Bergo MO. (2014) Antioxidants accelerate lung cancer progression in mice. Science translational medicine, 6(221). PMID: 24477002  

  • July 11, 2014
  • 04:53 AM
  • 75 views

FLCN is important for cardiomyocyte development

by Lizzie Perdeaux in BHD Research Blog

Cardiac hypertrophy is an adaptive response that occurs following increased stress on the heart wall, and can be caused by strenuous exercise, hypertension, heart attack or heart valve disease. In some cases, this can lead to heart failure. Although the … Continue reading →... Read more »

Hasumi Y, Baba M, Hasumi H, Huang Y, Lang M, Reindorf R, Oh HB, Sciarretta S, Nagashima K, Haines DC.... (2014) Folliculin (Flcn) inactivation leads to murine cardiac hypertrophy through mTORC1 deregulation. Human molecular genetics. PMID: 24908670  

  • July 11, 2014
  • 04:48 AM
  • 72 views

Maternal C-Reactive Protein (CRP) and offspring schizophrenia

by Paul Whiteley in Questioning Answers

A big quote to start this post: "This finding provides the most robust evidence to date that maternal inflammation may play a significant role in schizophrenia, with possible implications for identifying preventive strategies and pathogenic mechanisms in schizophrenia and other neurodevelopmental disorders".Ophelia @ Wikipedia The source for this quote was the paper by Sarah Canetta and colleagues [1] based on an analysis of serum samples from mums for C-reactive protein (CRP) as part of the Finnish Prenatal Study of Schizophrenia cohort under the leadership (well, grant holding) of Prof. Alan Brown. Some media interest in this paper can be seen here.Regular readers of this blog might have heard me talk about some of Prof. Brown's previous research, again with CRP in mind but with an autism research slant (see here). I'll come back to some of that work shortly alongside some more recent research [2] in that area.In this latest paper, archived maternal serum samples related to nearly 800 people (offspring) diagnosed with schizophrenia or schizo-affective disorder were assayed for CRP and results compared with maternal CRP levels related to a similarly sized asymptomatic control group. "Increasing maternal C-reactive protein levels, classified as a continuous variable, were significantly associated with schizophrenia in offspring (adjusted odds ratio=1.31, 95% confidence interval=1.10-1.56)". Even after controlling for confounders including a parental "history of psychiatric disorders" results remained significant. Ergo, one marker of inflammation present and elevated in spot sera samples of mums may have some implications for subsequent development of offspring.Having recently heard the sad news about the death of Paul Patterson (see his obituary here) my first thoughts turned to his valuable contributions to this area and the proposed maternal immune activation hypothesis of schizophrenia and autism [3] (open-access here). You'll note that Prof. Brown was the co-author on that last citation with Prof. Patterson, giving you a feel for how such research connections might fit together.My second thought was slightly more of a critical one with the realisation that CRP whilst a good marker of the acute-phase response linked to inflammation [4] may not necessarily present the whole picture when measured in a spot sample fashion or without reference to the multitude of other compounds reactive to an inflammatory status. Think cytokines for example (see here). I note also in the latest paper that maternal levels of CRP were the focus, and not specifically CRP levels in offspring with and without a diagnosis of schizophrenia. It would be interesting to see how the two measurements might correlate (or not). That being said, and as I've reported before, there is quite a body of evidence suggestive of on-going issues with CRP in at least a proportion of people on the schizophrenia spectrum. Inflammation and psychiatry seem to have some common ground (see here).Going back to the CRP work with autism in mind, I do think there is a pattern emerging from the available peer-reviewed evidence suggestive that inflammation (excess inflammation or elevated markers of inflammation?) during critical periods of pregnancy might have some connection with later offspring outcomes. The processes potentially relevant to any association are still the source of some speculation, as are the various ways that inflammation might come about: air pollution (see here), maternal obesity (see here), etc. Take yer pick, accepting that genetics and/or epigenetics are probably also going to play a role. What remains to be seen is how the idea of mitigating inflammation - however one goes about doing this - during those critical periods of pregnancy may impact on offspring risk of developmental or psychiatric outcomes. Indeed, as the paper from Patterson and Brown [3] concluded: "It has been suggested that the overall decline in bacterial illnesses due to antibiotic therapy and the initiation of immunization programs may be at least partially responsible for the reduction in the incidence of schizophrenia in certain countries in the last several decades". Does this mean such strategies have already impacted on some of the prevalence figures?---------- [1] Canetta S. et al. Elevated Maternal C-Reactive Protein and Increased Risk of Schizophrenia in a National Birth Cohort. Am J Psychiatry. 2014 Jun 27. doi: 10.1176/appi.ajp.2014.13121579.[2] Brown AS. et al. Elevated maternal C-reactive protein and autism in a national birth cohort. Mol Psychiatry. 2014 Feb;19(2):259-64.[3] Brown AS. & Patterson PH. Maternal infection and schizophrenia: implications for prevention. Schizophr Bull. 2011 Mar;37(2):284-90.----------Canetta, S., Sourander, A., Surcel, H., Hinkka-Yli-Salomäki, S., Leiviskä, J., Kellendonk, C., McKeague, I., & Brown, A. (2014). Elevated Maternal C-Reactive Protein and Increased Risk of Schizophrenia in a National Birth Cohort American Journal of Psychiatry DOI: 10.1176/appi.ajp.2014.13121579... Read more »

Canetta, S., Sourander, A., Surcel, H., Hinkka-Yli-Salomäki, S., Leiviskä, J., Kellendonk, C., McKeague, I., & Brown, A. (2014) Elevated Maternal C-Reactive Protein and Increased Risk of Schizophrenia in a National Birth Cohort. American Journal of Psychiatry. DOI: 10.1176/appi.ajp.2014.13121579  

  • July 10, 2014
  • 03:32 PM
  • 80 views

July 10, 2014

by Erin Campbell in HighMag Blog

Do your thoughts and feelings have colors? Do you feel red with rage during traffic, or green with envy when your lady swoons over Ryan Gosling? A recent methods paper introduces a very cool technique that allows the visualization and measurement of voltage within an excited neuron. Biologists build tools that are ideally accurate, fast, and non-damaging to the cells and organisms on which they are used. In a recent paper in Nature Methods, Hochbaum and colleagues describe the improved technique for simultaneous imaging of neuron stimulation and the resulting action potentials. Hochbaum and colleagues engineered a vector, called Optopatch, that uses their actuator (CheRiff) to induce action potentials and their voltage indicators (QuasAr1 and QuasAr2) to visualize and measure membrane voltage. Optopatch allows the measurement of action potentials on a microsecond timescale, without the need for electrodes. In the images above, a neuron expressing Optopatch shows action potential propagation (left to right, arrow is site of action potential initiation).Hochbaum, D., Zhao, Y., Farhi, S., Klapoetke, N., Werley, C., Kapoor, V., Zou, P., Kralj, J., Maclaurin, D., Smedemark-Margulies, N., Saulnier, J., Boulting, G., Straub, C., Cho, Y., Melkonian, M., Wong, G., Harrison, D., Murthy, V., Sabatini, B., Boyden, E., Campbell, R., & Cohen, A. (2014). All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins Nature Methods DOI: 10.1038/nmeth.3000Adapted by permission from Macmillan Publishers Ltd, copyright ©2014... Read more »

Hochbaum, D., Zhao, Y., Farhi, S., Klapoetke, N., Werley, C., Kapoor, V., Zou, P., Kralj, J., Maclaurin, D., Smedemark-Margulies, N.... (2014) All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins. Nature Methods. DOI: 10.1038/nmeth.3000  

  • July 10, 2014
  • 01:59 PM
  • 108 views

Don’t Listen to the Voices: Understanding Consciousness

by Gabriel in Lunatic Laboratories

There is a voice in my head. Don't worry it's mine... I think [a story for another time I'm sure], but why is my voice inside my head? What causes me to hear myself while I type these very words, or even better you to hear them in your voice as you read them? Consciousness is a complex and very confusing thing. I think therefore I am? Science has had trouble cracking that nut and philosophy just won't cut it in the realm of neuroscience. [...]... Read more »

Paller, K., & Suzuki, S. (2014) The source of consciousness. Trends in Cognitive Sciences. DOI: 10.1016/j.tics.2014.05.012  

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