Neuroscience

A recent review finds that over 97% of scientists believe that human activity is contributing to climate change. That is a very solid consensus of scientific opinion. This, of course, does not mean that the consensus must be correct, but (along with other data) it makes it unreasonable to claim that there is no consensus, or that there is significant scientific controversy on this topic. In fact, the 97% figure exactly matches prior surveys. Many scientific organizations have also officially endorsed this consensus. One of the common methods of deniers is to pretend as if there is a raging scientific controversy when in fact there is a solid consensus. Creationists, for example are constantly trying to portray evolution as a “theory in crisis,” when in fact it is doing quit well, thank you. The study employed an interesting methods. They reviewed 12,000 peer-reviewed published papers on topics relevant to climate change. They then tabulated, for those papers in which the researchers expressed a clear opinion about climate change, whether or not they supported the conclusion of anthropogenic global warming. In over 97% of cases they did. From the abstract: We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11?944 climate abstracts from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming. No survey is ever perfect – whenever you evaluate a subset of people in order to draw conclusions about the larger group, there is the possibility of selection bias. In this case one might argue that scientists who reject anthropogenic global warming are less likely to express those views in a peer-reviewed paper, or to have such views published. This method, however, is reasonable. They also backed this up with another phase of the study in which they invited authors to rate their own research and opinions, and 97.2% endorsed the consensus of global warming. While it’s possible to quibble about this number, given the strong agreements among various methods around the 97% figure, it’s difficult to argue that the true figure is significantly different. Why do we care about the consensus? Isn’t this just an argument from authority? Well, yes and no. It seems reasonable, especially for those who consider themselves skeptics, to argue that facts and logic should determine a scientific question, not authority. Or that we should “let the fact speak for themselves.” Unfortunately, facts cannot speak for themselves. Scientific evidence needs to be examined, rated for quality, interpreted, and put into a broader context. There is often no simple connect from facts to conclusions in science – background knowledge, knowledge of the processes of science, familiarity with critical thinking, logical pitfalls, and the effects of bias on interpretation are all necessary to come to a reliable conclusion about what those facts are telling us. Different individuals are likely to have different biases and knowledge bases, and therefore may come to different conclusions about the same set of data. No individual, therefore, can be the ultimate authority on any scientific question. The power of consensus is that individual quirks and biases will tend to average out. The consensus of scientific opinion, therefore, is a way to gauge the agreement and power of the scientific evidence. The only other alternative is to evaluate all the scientific evidence first hand and come to your own conclusion. The potential pitfall here, however, is that individuals who are not experts in the relevant field believe

The U.S. Centers for Disease Control has published a comprehensive summary of the epidemiology of childhood brain disorders in the most recent Morbidity and Mortality Weekly Report.This report produced some sensationalized headlines that up to 20% of children suffer from a mental disorder. However, I was more interested in looking at the prevalence estimates for some of the individual disorders from the report.The report collates data collected from a variety of surveys and data sets including the NHANES, NHIS and the National Survey of Children's Health (NSCH). These surveys typically use parental report to estimate prevalence ratesFor the purposes of this post, I will focus on two childhood brain disorders: attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).The key findings from the report in ADHD include:7.6% of parents reported their child between 3-17 years had received a diagnosis of ADHD in the NHIS8.9% of parents reported their child received a diagnosis of ADHD in the NSCH study9.6% to 12.3% of boys had received a diagnosis of ADHD3.8% to 5.4% of girls had received a diagnosis of ADHDA diagnosis of ADHD was more with older age, in children with health insurance and higher income groupsA diagnosis of ADHD was not related to parental education level The key findings from the report for autism and autism spectrum disorder include:.8% to 1.1% of parents reported their child between 3-17 years had received a diagnosis of autism1.8% of parents reported their child had received a diagnosis of ASDSurveys consisted noted a male predominance with boys having an estimated 3.5 to 4.5 times higher rate of autism and ASD diagnosisAgain having health insurance increased the rate of autism or ASD diagnosis by around two foldAutism and ASD prevalence rates were somewhat higher in the Northeast region of the U.S. and in white, non-Hispanic childrenIn contrast to ADHD, ASD rates were similar across parental income categoriesThe report notes in the discussion section: "Substantial but not insurmountable challenges to surveillance of mental disorders in children exists." They note current methods focus on parental reports and are biased by variability in access to health and mental health providers. The also note the imperfect diagnostic approach to childhood mental disorders and the need for more consistent diagnostic approaches.This report is a good comprehensive summary of what we know about these childhood brain disorders in the United States. Readers with more interest in this topic can access the free full text report in the citation below. In the next two posts, I will summarize key findings in the conduct disorder and affective disorder categories.Photo of clown fish from the Oklahoma Aquarium is from the author's files.Perou R, Bitsko RH, Blumberg SJ, Pastor P, Ghandour RM, Gfroerer JC, Hedden SL, Crosby AE, Visser SN, Schieve LA, Parks SE, Hall JE, Brody D, Simile CM, Thompson WW, Baio J, Avenevoli S, Kogan MD, Huang LN, & Division of Human Development and Disability, National Center on Birth Defects and Developmental Disabilities, CDC, Atlanta, Georgia (2013). Mental health surveillance among children - United States, 2005-2011. Morbidity and mortality weekly report. Surveillance summaries (Washington, D.C. : 2002), 62 (2), 1-35 PMID: 23677130... Perou R, Bitsko RH, Blumberg SJ, Pastor P, Ghandour RM, Gfroerer JC, Hedden SL, Crosby AE, Visser SN, Schieve LA.... (2013) Mental health surveillance among children - United States, 2005-2011. Morbidity and mortality weekly report. Surveillance summaries (Washington, D.C. : 2002), 62(2), 1-35. PMID: 23677130 Mental health surveillance among children - United States, 2005-2011.

“Our ancient countess was refused her desires will To bathe in pure fresh blood She’d peasant virgins killed Elizabeth, in the chasm where was my soul Forever young, Elizabeth Bathorii in the castle of your death You’re still alive, Elizabeth”                                                                         -“Elizabeth”, Ghost  As folklore has it, Elizabeth Bathorii, Countess of Hungary, often bathed in […]... Villeda SA, Luo J, Mosher KI, Zou B, Britschgi M, Bieri G, Stan TM, Fainberg N, Ding Z, Eggel A.... (2011) The ageing systemic milieu negatively regulates neurogenesis and cognitive function. Nature, 477(7362), 90-4. PMID: 21886162 The ageing systemic milieu negatively regulates neurogenesis and cognitive function. Loffredo FS, Steinhauser ML, Jay SM, Gannon J, Pancoast JR, Yalamanchi P, Sinha M, Dall'osso C, Khong D, Shadrach JL.... (2013) Growth Differentiation Factor 11 Is a Circulating Factor that Reverses Age-Related Cardiac Hypertrophy. Cell, 153(4), 828-39. PMID: 23663781 Growth Differentiation Factor 11 Is a Circulating Factor that Reverses Age-Related Cardiac Hypertrophy. Zhang G, Li J, Purkayastha S, Tang Y, Zhang H, Yin Y, Li B, Liu G, & Cai D. (2013) Hypothalamic programming of systemic ageing involving IKK-?, NF-?B and GnRH. Nature, 497(7448), 211-6. PMID: 23636330 Hypothalamic programming of systemic ageing involving IKK-?, NF-?B and GnRH.

Synapses, the connections between neurons can strengthen and weaken depending on the specific activity at that synapse. This is called synaptic plasticity, and we've talked about it a lot on this blog (here, here, here and here).the strengthening and weakening of synaptic connections corresponds to the spine growing or shrinking (Matsuzaki 2007)However, there is another kind of plasticity that can occur at synapses. This is called homeostatic plasticity. And instead of the synapse strengthening or weakening depending on the specific activity at that synapse, the synapses strengthen and weaken in homeostatic plasticity depending on the activity of the whole cell. To drastically simplify, each cell 'wants' to fire about a certain amount, if it suddenly starts to fire a lot less, it will take steps to strengthen its connections or make itself more 'excitable' so it can get back to its preferred amount of firing. Similarly if the cell starts to fire a lot more than normal, it will take steps to make itself less excitable and to weaken its connections until it reaches the right amount of firing. Thorny Excrescences from Lee et al., (2013)A recent paper from the Pak lab explains how in some specific neurons in the hippocampus (CA3 pyramidal cells), the activity of the whole cell is strongly controlled by a some very peculiar synapses. These synapses are close to the cell body, and are on these HUGE weirdly shaped spines (see above) called "Thorny Excrescences". For comparison 'normal' spines look more like this:Spines from Lee et al. (2013)The Thorny Excrescences (TEs) are massive spines that contain many separate synapses on them, but connect to the dendrite through 1 neck. 'Normal' spines, on the other hand, usually have 1 synapse at the spine head, and connect to the dendrite through 1 neck.The size of the TEs, and their proximity to the soma makes them an extremely powerful way to control the signals that the soma receives. Lee et al (2013) shows that when you drastically reduce activity by blocking action potentials (using TTX), you get massive growth of these TEs, but the normal spines further away from the soma stay the same.They test 3 things to determine whether the TEs have undergone homeostatic plasticity. They look at the morphology (they are bigger), the activity (the electrical signals from them are bigger) and the molecular signatures (the molecules indicative of new synapses are more plentiful). The paper is a really nice complete story showing that these TEs have a lot of control over the general activity of the cell.It also solves an important problem with homeostatic plasticity. That is, how can the general activity of the cell be modulated without the specific differences between synapses being erased, and consequently the memories or pieces of information they encode? If homeostatic plasticity occurs at spines dedicated to it, then the other spines can still encode specific signals while the activity of the cell as a whole changes. © TheCellularScaleLee KJ, Queenan BN, Rozeboom AM, Bellmore R, Lim ST, Vicini S, & Pak DT (2013). Mossy fiber-CA3 synapses mediate homeostatic plasticity in mature hippocampal neurons. Neuron, 77 (1), 99-114 PMID: 23312519... Lee KJ, Queenan BN, Rozeboom AM, Bellmore R, Lim ST, Vicini S, & Pak DT. (2013) Mossy fiber-CA3 synapses mediate homeostatic plasticity in mature hippocampal neurons. Neuron, 77(1), 99-114. PMID: 23312519 Mossy fiber-CA3 synapses mediate homeostatic plasticity in mature hippocampal neurons.

by Max C. Liebau, Fabian Braun, Katja Höpker, Claudia Weitbrecht, Valerie Bartels, Roman-Ulrich Müller, Susanne Brodesser, Moin A. Saleem, Thomas Benzing, Bernhard Schermer, Markus Cybulla, Christine E. Kurschat Fabry’s disease results from an inborn error of glycosphingolipid metabolism that is due to deficiency of the lysosomal hydrolase ?-galactosidase A. This X-linked defect results in the accumulation of enzyme substrates with terminally ?-glycosidically bound galactose, mainly the neutral glycosphingolipid Globotriaosylceramide (Gb3) in various tissues, including the kidneys. Although end-stage renal disease is one of the most common causes of death in hemizygous males with Fabry’s disease, the pathophysiology leading to proteinuria, hematuria, hypertension, and kidney failure is not well understood. Histological studies suggest that the accumulation of Gb3 in podocytes plays an important role in the pathogenesis of glomerular damage. However, due to the lack of appropriate animal or cellular models, podocyte damage in Fabry’s disease could not be directly studied yet. As murine models are insufficient, a human model is needed. Here, we developed a human podocyte model of Fabry’s disease by combining RNA interference technology with lentiviral transduction of human podocytes. Knockdown of ?-galactosidase A expression resulted in diminished enzymatic activity and slowly progressive accumulation of intracellular Gb3. Interestingly, these changes were accompanied by an increase in autophagosomes as indicated by an increased abundance of LC3-II and a loss of mTOR kinase activity, a negative regulator of the autophagic machinery. These data suggest that dysregulated autophagy in ?-galactosidase A-deficient podocytes may be the result of deficient mTOR kinase activity. This finding links the lysosomal enzymatic defect in Fabry’s disease to deregulated autophagy pathways and provides a promising new direction for further studies on the pathomechanism of glomerular injury in Fabry patients.

by Janice D. Boyd, Donald J. Brightsmith Study of animal movements is key for understanding their ecology and facilitating their conservation. The Argos satellite system is a valuable tool for tracking species which move long distances, inhabit remote areas, and are otherwise difficult to track with traditional VHF telemetry and are not suitable for GPS systems. Previous research has raised doubts about the magnitude of position errors quoted by the satellite service provider CLS. In addition, no peer-reviewed publications have evaluated the usefulness of the CLS supplied error ellipses nor the accuracy of the new Kalman filtering (KF) processing method. Using transmitters hung from towers and trees in southeastern Peru, we show the Argos error ellipses generally contain

by Samantha Bui, Frode Oppedal, Øyvind J. Korsøen, Damien Sonny, Tim Dempster Understanding species-specific flight behaviours is essential in developing methods of guiding fish spatially, and requires knowledge on how groups of fish respond to aversive stimuli. By harnessing their natural behaviours, the use of physical manipulation or other potentially harmful procedures can be minimised. We examined the reactions of sea-caged groups of 50 salmon (1331±364 g) to short-term exposure to visual or acoustic stimuli. In light experiments, fish were exposed to one of three intensities of blue LED light (high, medium and low) or no light (control). Sound experiments included exposure to infrasound (12 Hz), a surface disturbance event, the combination of infrasound and surface disturbance, or no stimuli. Groups that experienced light, infrasound, and the combination of infrasound and surface disturbance treatments, elicited a marked change in vertical distribution, where fish dived to the bottom of the sea-cage for the duration of the stimulus. Light treatments, but not sound, also reduced the total echo-signal strength (indicative of swim bladder volume) after exposure to light, compared to pre-stimulus levels. Groups in infrasound and combination treatments showed increased swimming activity during stimulus application, with swimming speeds tripled compared to that of controls. In all light and sound treatments, fish returned to their pre-stimulus swimming depths and speeds once exposure had ceased. This work establishes consistent, short-term avoidance responses to these stimuli, and provides a basis for methods to guide fish for aquaculture applications, or create avoidance barriers for conservation purposes. In doing so, we can achieve the manipulation of group position with minimal welfare impacts, to create more sustainable practices.

by Hyunhee Kim, Ricardo Zamel, Xiao-Hui Bai, Mingyao Liu A variety of airborne pathogens can induce inflammatory responses in airway epithelial cells, which is a crucial component of host defence. However, excessive inflammatory responses and chronic inflammation also contribute to different diseases of the respiratory system. We hypothesized that the activation of protein kinase C (PKC) is one of the essential mechanisms of inflammatory response in airway epithelial cells. In the present study, we stimulated human bronchial lung epithelial (BEAS-2B) cells with the phorbol ester Phorbol 12, 13-dibutyrate (PDBu), and examined gene expression profile using microarrays. Microarray analysis suggests that PKC activation induced dramatic changes in gene expression related to multiple cellular functions. The top two interaction networks generated from these changes were centered on NF?B and TNF-?, which are two commonly known pathways for cell death and inflammation. Subsequent tests confirmed the decrease in cell viability and an increase in the production of various cytokines. Interestingly, each of the increased cytokines was differentially regulated at mRNA and/or protein levels by different sub-classes of PKC isozymes. We conclude that pathological cell death and cytokine production in airway epithelial cells in various situations may be mediated through PKC related signaling pathways. These findings suggest that PKCs can be new targets for treatment of lung diseases.

by Wim Tops, Ellen Verguts, Maaike Callens, Marc Brysbaert Background Few studies are available about the personality profile of higher education students with dyslexia and to which extent this could be any different from their non-dyslexic peers. Aims and Sample(s) To obtain empirical evidence, we compared the personality profile of a group of 100 Dutch-speaking students with dyslexia with that of a control group of 100 students without learning disabilities. Methods The NEO-PI-R based on the Big Five in personality research was used. Results and Conclusions Our study showed no differences in the personality between both groups. This agrees with a recent meta-analysis of English findings (Swanson & Hsieh, 2009), suggesting that students with dyslexia do not perceive themselves differently than their non-dyslexic peers. Practical implications and directions for future research are considered.

by David Bruce Borenstein, Yigal Meir, Joshua W. Shaevitz, Ned S. Wingreen Many cellular populations cooperate through the secretion of diffusible extracellular resources, such as digestive enzymes or virulence factors. Diffusion of these resources leads to long-range intercellular interactions, creating the possibility of cooperation but also the risk of exploitation by non-producing neighbors. In the past, considerable attention has been given to game-theoretic lattice models of intercellular cooperation. In these models, coexistence is commonly observed between cooperators (corresponding to resource producers) and cheaters (corresponding to nonproducers). However, these models consider only interactions between direct competitors. We find that when individuals are allowed to interact non-locally through the diffusion of a shared resource coexistence between cooperators and cheaters is lost. Instead, we find population dynamics similar to simple competition, either neutral or biased, with no balancing selection that would favor coexistence. Our results highlight the importance of an accurate treatment of diffusion of shared resources and argue against the generality of the conclusions of game-theoretic lattice models.