Revisiting the Role of Neurons in Neurovascular Coupling

In this article, we will review molecular, anatomical, physiological and pharmacological data in an attempt to better understand how excitatory and inhibitory neurons recruited by distinct afferent inputs to the cerebral cortex contribute to the coupled hemodynamic response, and how astrocytes can act as intermediaries to these neuronal populations. We aim at providing the pros and cons to the following statements that, depending on the nature of the afferent input to the neocortex, (i) different neuronal or astroglial messengers, likely acting in sequence, mediate the hemodynamic changes, (ii) some recruited neurons release messengers that directly alter blood vessel tone, (iii) others act by modulating neuronal and astroglial activity, and (iv) astrocytes act as intermediaries for both excitatory and inhibitory neurotransmitters. We will stress that a given afferent signal activates a precise neuronal circuitry that determines the mediators of the hemodynamic response as well as the level of interaction with surrounding astrocytes

“iCub, clean the table!” A robot learning from demonstration approach using Deep Neural Networks

Autonomous service robots have become a key research topic in robotics, particularly for household chores. A typical home scenario is highly unconstrained and a service robot needs to adapt constantly to new situations. In this paper, we address the problem of autonomous cleaning tasks in uncontrolled environments. In our approach, a human instructor uses kinestethic demonstrations to teach a robot how to perform different cleaning tasks on a table. Then, we use Task Parametrized Gaussian Mixture Models (TP-GMMs) to encode the demonstrations variability, while providing appropriate generalization abilities. TP-GMMs extend Gaussian Mixture Models with an auxiliary set of reference frames, in order to extrapolate the demonstrations to different task parameters such as movement locations, amplitude or orientations. However, the reference frames (that parametrize TP-GMMs) can be very difficult to extract in practice, as it may require segmenting the cluttered images of the working table-top. Instead, in this work the reference frames are automatically extracted from robot camera images, using a deep neural network that was trained during human demonstrations of a cleaning task. This approach has two main benefits: (i) it takes the human completely out of the loop while performing complex cleaning tasks; and (ii) the network is able to identify the specific task to be performed directly from image data, thus also enabling automatic task selection from a set of previously demonstrated tasks. The system was implemented on the iCub humanoid robot. During the tests, the robot was able to successfully clean a table with two different types of dirt (wiping a marker’s scribble or sweeping clusters of lentils).info:eu-repo/semantics/publishedVersio

Common Origins of Hippocampal Ivy and Nitric Oxide Synthase Expressing Neurogliaform Cells

GABAergic interneurons critically regulate cortical computation through exquisite spatio-temporal control over excitatory networks. Precision of this inhibitory control requires a remarkable diversity within interneuron populations that is largely specified during embryogenesis. Although nNOS+ interneurons constitute the largest hippocampal interneuron cohort their origin and specification remain unknown. Thus, as neurogliaform (NGC) and Ivy cells (IvC) represent the main nNOS+ interneurons we investigated their developmental origins. Although considered distinct interneuron subtypes NGCs and IvCs exhibited similar neurochemical and electrophysiological signatures including NPY expression and late-spiking. Moreover, lineage analyses, including loss-of-function experiments and inducible fate-mapping, indicated that nNOS+ IvCs and NGCs are both derived from medial ganglionic eminence (MGE) progenitors under control of the transcription factor Nkx2-1. Surprisingly, a subset of NGCs lacking nNOS arises from caudal ganglionic eminence (CGE) progenitors. Thus, while nNOS+ NGCs and IvCs arise from MGE progenitors, a CGE origin distinguishes a discrete population of nNOS-NGCs

Similarities and differences between younger and older disease onset patients with newly diagnosed systemic lupus erythematosus

Objectives: Several studies show that age at onset has an impact on the clinical-serological presentation, comorbidities and disease course of patients with systemic lupus erythematosus (SLE). We evaluated whether, in patients with recent onset SLE, the age at onset correlates with clinical-serological manifestations and with comorbidities. Methods: We analysed 171 patients with a SLE diagnosis obtained within 12 months of diagnosis enrolled in the Early Lupus project. Based on the age of onset of the first disease symptom, they were stratified into 2 groups: early onset (18-45 years) and late onset (>45 years). The analysis was replicated by stratifying patients based on age at diagnosis (fulfillment of ACR classification criteria). Each comparison was made at baseline and at 36 months of follow-up. Results: Baseline: patients with late onset displayed comorbidities (hypertension, dyslipidemia and osteoporosis) more frequently than early onset group. 11.4% of late onset patients had a malignancy in medical history, not recorded in the early onset cohort. The two groups differed neither in organ involvement (domain BILAG) nor in disease activity (ECLAM). Patients with early onset showed a disease with signs of higher serologic activity (higher frequency of anti-dsDNA positivity and lower mean C3 and C4 levels) and had malar rash more frequently than the late onset group (36.2% vs. 18.2%, p=0.042). Similar results were obtained by stratifying patients by age of diagnosis (18-45 years and >45 years), except for the higher frequency of discoid rash in the group with age at diagnosis >45 years (18% vs. 6.6%, p=0.045). 36 months: the 2 groups of patients independently of the stratification applied did not differ in the accumulation of damage, but showed a different pattern of 8 organ involvement. Musculoskeletal involvement was more frequent both in the late onset group (18.6% vs. 7.3%, p=0.043) and in the group with age at diagnosis >45 years (20.4% vs. 5.9%, p=0.009) compared to their counterparts, while renal involvement was more frequent in the group with age at diagnosis 18-45 years (21.4% vs. 6.1%, p=0.03).A sub analysis at 36 months on patients without hypertension and osteoporosis at enrollment showed that patients with older age at onset had a higher frequency of these comorbidities, compared to their counterparts. Conclusions: In our cohort, younger disease SLE onset seems to correlate with a more active immunological profile, while late onset with a higher incidence of comorbidities

New insights into the classification and nomenclature of cortical GABAergic interneurons.

A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus

COX-2-Derived Prostaglandin E2 Produced by Pyramidal Neurons Contributes to Neurovascular Coupling in the Rodent Cerebral Cortex

International audienceVasodilatory prostaglandins play a key role in neurovascular coupling (NVC), the tight link between neuronal activity and local cerebral blood flow, but their precise identity, cellular origin and the receptors involved remain unclear. Here we show in rats that NMDA-induced vasodilation and hemodynamic responses evoked by whisker stimulation involve cyclooxygenase-2 (COX-2) activity and activation of the prostaglandin E2 (PgE(2)) receptors EP2 and EP4. Using liquid chromatography-electrospray ionization-tandem mass spectrometry, we demonstrate that PgE(2) is released by NMDA in cortical slices. The characterization of PgE2 producing cells by immunohistochemistry and single-cell reverse transcriptase-PCR revealed that pyramidal cells and not astrocytes are the main cell type equipped for PgE2 synthesis, one third expressing COX-2 systematically associated with a PgE2 synthase. Consistent with their central role in NVC, in vivo optogenetic stimulation of pyramidal cells evoked COX-2-dependent hyperemic responses in mice. These observations identify PgE2 as the main prostaglandin mediating sensory-evoked NVC, pyramidal cells as their principal source and vasodilatory EP2 and EP4 receptors as their targets

Management of psoriatic arthritis: a consensus opinion by expert rheumatologists

Background: Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disease involving several articular and extra-articular structures. Despite the important progresses recently made in all of the aspects of this disease, its management is still burdened by unresolved issues. The aim of this exercise was to provide a set of statements that may be helpful for the management of PsA. Methods: A group of 38 Italian rheumatologists with recognized expertise in PsA selected and addressed the following four topics: "early PsA," "axial-PsA," "extra-articular manifestations and comorbidities," "therapeutic goals." Relevant articles from the literature (2016-2022) were selected by the experts based on a PubMed search. A number of statements for each topic were elaborated. Results: Ninety-four articles were selected and evaluated, 68 out of the 1,114 yielded by the literature search and 26 added by the Authors. Each of the four topic was subdivided in themes as follows: transition from psoriasis to PsA, imaging vs. CASPAR criteria in early diagnosis, early treatment for "early PsA"; axial-PsA vs. axialspondyloarthritis, diagnosis, clinical evaluation, treatment, standard radiography vs. magnetic resonance imaging for "axial PsA"; influence of inflammatory bowel disease on the therapeutic choice, cardiovascular comorbidity, bone damage, risk of infection for "comorbidities and extra-articular manifestations"; target and tools, treat-to-target strategy, role of imaging for "therapeutic goals." The final document consisted of 49 statements. Discussion: The final product of this exercise is a set of statements concerning the main issues of PsA management offering an expert opinion for some unmet needs of this complex disease

Cell Type–Specific Thalamic Innervation in a Column of Rat Vibrissal Cortex

This is the concluding article in a series of 3 studies that investigate the anatomical determinants of thalamocortical (TC) input to excitatory neurons in a cortical column of rat primary somatosensory cortex (S1). We used viral synaptophysin-enhanced green fluorescent protein expression in thalamic neurons and reconstructions of biocytin-labeled cortical neurons in TC slices to quantify the number and distribution of boutons from the ventral posterior medial (VPM) and posteromedial (POm) nuclei potentially innervating dendritic arbors of excitatory neurons located in layers (L)2–6 of a cortical column in rat somatosensory cortex. We found that 1) all types of excitatory neurons potentially receive substantial TC input (90–580 boutons per neuron); 2) pyramidal neurons in L3–L6 receive dual TC input from both VPM and POm that is potentially of equal magnitude for thick-tufted L5 pyramidal neurons (ca. 300 boutons each from VPM and POm); 3) L3, L4, and L5 pyramidal neurons have multiple (2–4) subcellular TC innervation domains that match the dendritic compartments of pyramidal cells; and 4) a subtype of thick-tufted L5 pyramidal neurons has an additional VPM innervation domain in L4. The multiple subcellular TC innervation domains of L5 pyramidal neurons may partly explain their specific action potential patterns observed in vivo. We conclude that the substantial potential TC innervation of all excitatory neuron types in a cortical column constitutes an anatomical basis for the initial near-simultaneous representation of a sensory stimulus in different neuron types

Local circuits targeting parvalbumin-containing interneurons in layer IV of rat barrel cortex

Interactions between inhibitory interneurons and excitatory spiny neurons and also other inhibitory cells represent fundamental network properties which cause the so-called thalamo-cortical response transformation and account for the well-known receptive field differences of cortical layer IV versus thalamic neurons. We investigated the currently largely unknown morphological basis of these interactions utilizing acute slice preparations of barrel cortex in P19-21 rats. Layer IV spiny (spiny stellate, star pyramidal and pyramidal) neurons or inhibitory (basket and bitufted) interneurons were electrophysiologically characterized and intracellularly biocytin-labeled. In the same slice, we stained parvalbumin-immunoreactive (PV-ir) interneurons as putative target cells after which the tissue was subjected to confocal image acquisition. Parallel experiments confirmed the existence of synaptic contacts in these types of connection by correlated light and electron microscopy. The axons of the filled neurons differentially targeted barrel PV-ir interneurons: (1) The relative number of all contacted PV-ir cells within the axonal sphere was 5–17% for spiny (n = 10), 32 and 58% for basket (n = 2) and 12 and 13% for bitufted (n = 2) cells. (2) The preferential subcellular site which was contacted on PV-ir target cells was somatic for four and dendritic for five spiny cells; for basket cells, there was a somatic and for bitufted cells a dendritic preference in each examined case. (3) The highest number of contacts on a single PV-ir cell was 9 (4 somatic and 5 dendritic) for spiny neurons, 15 (10 somatic and 5 dendritic) for basket cells and 4 (1 somatic and 3 dendritic) for bitufted cells. These patterns suggest a cell type-dependent communication within layer IV microcircuits in which PV-ir interneurons provide not only feed-forward but also feedback inhibition thus triggering the thalamo-cortical response transformation

Risk for cancer development in familial Mediterranean fever and associated predisposing factors: an ambidirectional cohort study from the international AIDA Network registries

Objective: Inflammation has been associated with an increased risk for cancer development, while innate immune system activation could counteract the risk for malignancies. Familial Mediterranean fever (FMF) is a severe systemic inflammatory condition and also represents the archetype of innate immunity deregulation. Therefore, the aim of this study is to investigate the risk for cancer development in FMF. Methods: The risk ratio (RR) for malignancies was separately compared between FMF patients and fibromyalgia subjects, Still's disease patients and Behçet's disease patients. Clinical variables associated with cancer development in FMF patients were searched through binary logistic regression. Results: 580 FMF patients and 102 fibromyalgia subjects, 1012 Behçet's disease patients and 497 Still's disease patients were enrolled. The RR for the occurrence of malignant neoplasms was 0.26 (95% Confidence Interval [CI.] 0.10-0.73, p=0.006) in patients with FMF compared to fibromyalgia subjects; the RR for the occurrence of malignant cancer was 0.51 (95% CI. 0.23-1.16, p=0.10) in FMF compared to Still's disease and 0.60 (95% CI. 0.29-1.28, p=0.18) in FMF compared to Behçet's disease. At logistic regression, the risk of occurrence of malignant neoplasms in FMF patients was associated with the age at disease onset (β1 = 0.039, 95% CI. 0.001-0.071, p=0.02), the age at the diagnosis (β1 = 0.048, 95% CI. 0.039-0.085, p=0.006), the age at the enrolment (β1 = 0.05, 95% CI. 0.007-0.068, p=0.01), the number of attacks per year (β1 = 0.011, 95% CI. 0.001- 0.019, p=0.008), the use of biotechnological agents (β1 = 1.77, 95% CI. 0.43-3.19, p=0.009), the use of anti-IL-1 agents (β1 = 2.089, 95% CI. 0.7-3.5, p=0.002). Conclusions: The risk for cancer is reduced in Caucasic FMF patients; however, when malignant neoplasms occur, this is more frequent in FMF cases suffering from a severe disease phenotype and presenting a colchicine-resistant disease