Neural evidence for an association between social proficiency and sensitivity to social reward

Data from developmental psychology suggests a link between the growth of socio-emotional competences and the infant''s sensitivity to the salience of social stimuli. The aim of the present study was to find evidence for this relationship in healthy adults. Thirty-five participants were recruited based on their score above the 85th or below the 15th percentile of the empathy quotient questionnaire (EQ, Baron-Cohen and Wheelwright, 2004). Functional magnetic resonance imaging (fMRI) was used to compare neural responses to cues of social and non-social (monetary) reward. When compared to the high-EQ group, the low-EQ group showed reduced activity of the brain s reward system, specifically the right nucleus accumbens, in response to cues predictive of social reward (videos showing gestures of approval)—but increased activation in this area for monetary incentives. Our data provide evidence for a link between self-reported deficits in social proficiency and reduced sensitivity to the motivational salience of positive social stimuli.     

Verbal working memory impairments following traumatic brain injury: an fNIRS investigation

The construct of working memory and its reliance on dorsolateral prefrontal cortex (DLPFC) have been the focus of many studies in healthy subjects and in clinical populations. However, transfer of knowledge gained from cognitive science studies to clinical applications can be a challenging goal. This scarce cross-dissemination may be partially due to the use of ‘tools’ that are limited in their ability to generate meaningful information about impairments in clinical groups. To this end, this paper investigates the use of functional near-infrared spectroscopy (fNIRS), which offers unique opportunities for recording neuroactivation. Specifically, we examine measures of the DLPFC hemodynamic response during a working memory task in adults with traumatic brain injury (TBI) and healthy controls. Analysis of hemodynamic measures showed significant differences between the two groups, even without differences in behavioral performance. Additional subtle disparities were linked to levels of performance in TBI and healthy subjects. fNIRS hemodynamic measures may therefore provide novel information to existing theories and knowledge of the working memory construct. Future studies may further define these subtle differences captured by fNIRS to help identify which components affect inter-individual variations in performance and could play a contributing role in the choice and planning of neurorehabilitation interventions targeting working memory.     

Proposition for new terminologies in PCNL: what does ‘ultra-mini-micro’ actually mean?

Ever smaller miniaturised techniques are being developed for percutaneous nephrolithotomy (PCNL), with access sheaths now as small as 4.8Fr being used in adults. With the ever expanding use of the terms “micro” “mini” or “ultra” techniques, the terminology can be somewhat confusing. We propose a simple classification system to standardise the terminology for PCNL, encapsulating technological and procedural advancements.     

Non‐epileptic myoclonic attacks in infancy: three cases

Since the first cases of abnormal paroxystic movements in normal infants were described, the importance of accurate characterization of this medical condition has been increasingly confirmed in the literature. Non‐epileptic attacks mimic epileptic paroxysms in clinical presentation, but they have a typically benign course and are unresponsive to pharmacological treatment. An evident feature of the syndrome is its extreme variability in clinical manifestation. Here, we describe three normal infants with two similar forms of non‐epileptic paroxysms. Electroclinical manifestations and profile of evolution were investigated. Ictal video‐EEG polygraphic recordings were obtained for each patient. The increasing number of such reported clinical cases in the literature may contribute to high quality systematic reviews and the development of useful guidelines in the future. The clinical heterogeneity of non‐epileptic attacks, together with the relative rarity of the condition, may make differential diagnosis with epileptic attacks very challenging. [Published with video sequences]     

Diffractive trifocal lens implantation with or without excimer laser enhancement: is a touch-up procedure a negative predictor for refractive and subjective outcome?

Graefe's Archive for Clinical and Experimental Ophthalmology - To investigate the refractive results of a LASIK enhancement and its impact on treatment safety, efficacy, predictability and...     

The role of Müller cell glucocorticoid signaling in diabetic retinopathy

Graefe's Archive for Clinical and Experimental Ophthalmology - Diabetic retinopathy (DR) is a sight-threatening complication associated with the highly prevalent diabetes disorder. Both the...     

The diagnosis and management of temporal arteritis

Temporal arteritis (TA), or giant cell arteritis, is a systemic autoimmune vasculitis affecting patients over 50 years of age. It can cause rapid, irreversible bilateral vision loss in older adults and is therefore considered an ophthalmological emergency. Many of the symptoms and signs of TA can be vague, non-specific and gradual in onset, often leading to a delayed or inaccurate diagnosis. As such, it is important for a wide variety of primary optometrists and health practitioners to maintain a robust understanding of the clinical presentation, key investigations and time-sensitive management of this disease, as early initiation of treatment for TA can be vision- and life-saving.     

Global structural changes of an ion channel during its gating are followed by ion mobility mass spectrometry

Mechanosensitive ion channels are sensors probing membrane tension in all species; despite their importance and vital role in many cell functions, their gating mechanism remains to be elucidated. Here, we determined the conditions for releasing intact mechanosensitive channel of large conductance (MscL) proteins from their detergents in the gas phase using native ion mobility–mass spectrometry (IM-MS). By using IM-MS, we could detect the native mass of MscL from Escherichia coli, determine various global structural changes during its gating by measuring the rotationally averaged collision cross-sections, and show that it can function in the absence of a lipid bilayer. We could detect global conformational changes during MscL gating as small as 3%. Our findings will allow studying native structure of many other membrane proteins.One of the best candidates to explore the gating of mechanosensitive channels is the mechanosensitive channel of large conductance (MscL) from Escherichia coli. The crystal structure of MscL in its closed/nearly closed state from Mycobacterium tuberculosis revealed this channel as a homopentamer (1). Each subunit has a cytoplasmic N- and C-terminal domain as well as two α-helical transmembrane (TM) domains, TM1 and TM2, which are connected by a periplasmic loop. The five TM1 helices form the pore and the more peripheral TM2 helices interact with the lipid bilayer.MscL detects changes in membrane tension invoked by a hypoosmotic shock and couples the tension sensing directly to large conformational changes (1, 2). On the basis of a large body of structural and theoretical data, numerous gating models of MscL have been proposed (3–9). These models agree upon (i) the hydrophobic pore constriction of the channel and (ii) the channel opens by an iris-like rotation—i.e., a tilting and outward movement of transmembrane helices that make the channel wider and shorter (5). This mechanism is supported by patch-clamp (10), disulfide cross-linking (11), FRET spectroscopy (12), and site-directed spin labeling EPR experiments (6, 7), as well as computational studies (13–15). So far, direct experimental results have only been observed for short-range local structural changes, and no measure of the overall global structural changes during channel gating have been reported. Because there is no crystal structure available for the open MscL channel, elucidating overall global structural changes from the onset of channel activation is of utmost importance for our understanding of the gating mechanism of mechanosensitive channels. Here, we provide direct experimental evidence for the key areal changes occurring during channel gating by combining our ability to activate MscL in a controlled manner to different subopen states (16) with a native ion mobility-mass spectrometry (IM-MS) approach.