Search results for "cortex"
showing 10 items of 1827 documents
Endothelial Dab1 signaling orchestrates neuro-glia-vessel communication in the central nervous system.
2018
Developing the bloodbrain barrier During development, signals need to be dynamically integrated by endothelial cells, neurons, and glia to achieve functional neuro-glia-vascular units in the central nervous system. During cortical development, neuronal Dab1 and ApoER2 receptors respond to a guidance cue called reelin. Studying mice, Segarra et al. found that Dab1 and ApoER2 are also expressed in endothelial cells (see the Perspective by Thomas). The integration of reelin signaling in endothelial cells and neurons facilitates the communication between vessels, glia, and neurons that is necessary for the correct positioning of neurons during cortical development. This integration is also impo…
Cerebello-cortical network fingerprints differ between essential, Parkinson's and mimicked tremors.
2017
Cerebello-thalamo-cortical loops play a major role in the emergence of pathological tremors and voluntary rhythmic movements. It is unclear whether these loops differ anatomically or functionally in different types of tremor. We compared age- and sex-matched groups of patients with Parkinson's disease or essential tremor and healthy controls (n = 34 per group). High-density 256-channel EEG and multi-channel EMG from extensor and flexor muscles of both wrists were recorded simultaneously while extending the hands against gravity with the forearms supported. Tremor was thereby recorded from patients, and voluntarily mimicked tremor was recorded from healthy controls. Tomographic maps of EEG-E…
Activation of Corticothalamic Layer 6 Cells Decreases Angular Tuning in Mouse Barrel Cortex.
2019
In the mouse whisker system, the contribution of L6 corticothalamic cells (L6 CT) to cortical and thalamic processing of the whisker deflection direction was investigated. A genetically defined population of L6 CT cells project to infragranular GABAergic interneurons that hyperpolarize neurons in somatosensory barrel cortex (BC). Optogenetic activation of these neurons switched BC to an adapted mode in which excitatory cells lost their angular tuning. In contrast, however, this was not the case with a general activation of inhibitory interneurons via optogenetic activation of Gad2-expressing cells. The decrease in angular tuning, when L6 CT cells were activated, was due to changes in cortic…
Network effects and pathways in Deep brain stimulation in Parkinson's disease.
2016
Deep brain stimulation of subthalamic nucleus (STN-DBS) became a standard therapeutic option in Parkinson's disease (PD), even though the underlying modulated network of STN-DBS is still poorly described. Probabilistic tractography and connectivity analysis as derived from diffusion tensor imaging (DTI) were performed together with modelling of implanted electrode positions and linked postoperative clinical outcome. Fifteen patients with idiopathic PD without dementia were selected for DBS treatment. After pre-processing, probabilistic tractography was run from cortical and subcortical seeds of the hypothesized network to targets represented by the positions of the active DBS contacts. The …
The TrkB agonist 7,8-dihydroxyflavone changes the structural dynamics of neocortical pyramidal neurons and improves object recognition in mice
2018
This is a pre-print of an article published in Brain Structure and Function. The final authenticated version is available online at: https://doi.org/10.1007/s00429-018-1637-x. BDNF and its receptor TrkB have important roles in neurodevelopment, neural plasticity, learning, and memory. Alterations in TrkB expression have been described in different CNS disorders. Therefore, drugs interacting with TrkB, specially agonists, are promising therapeutic tools. Among them, the recently described 7,8-dihydroxyflavone (DHF), an orally bioactive compound, has been successfully tested in animal models of these diseases. Recent studies have shown the influence of this drug on the structure of pyramidal …
Broad neurodevelopmental features and cortical anomalies associated with a novel de novo KMT2A variant in Wiedemann-Steiner syndrome.
2021
Abstract Wiedemann-Steiner syndrome (WDSTS) is a rare genetic disorder including developmental delay/intellectual disability (DD/ID), hypertrichosis cubiti, short stature, and distinctive facial features, caused by mutation in KMT2A gene, which encodes a histone methyltransferase (H3K4) that regulates chromatin-mediated transcription. Different neurodevelopmental phenotypes have been described within the WDSTS spectrum, including a peculiar Autism Spectrum Disorder (ASDs) subtype in some affected individuals. Here, we report a 9-year-old Caucasian male found by next-generation panel sequencing to carry a novel heterozygous de novo KMT2A frameshift variant (NM_001197104.2:c.4433delG; p. Arg1…
Somatosensory Brain Function and Gray Matter Regional Volumes Differ According to Exercise History : Evidence from Monozygotic Twins
2017
Associations between long-term physical activity and cortical function and brain structure are poorly known. Our aim was to assess whether brain functional and/or structural modulation associated with long-term physical activity is detectable using a discordant monozygotic male twin pair design. Nine monozygotic male twin pairs were carefully selected for an intrapair difference in their leisure-time physical activity of at least three years duration (mean age 34 ± 1 years). We registered somatosensory mismatch response (SMMR) in EEG to electrical stimulation of fingers and whole brain MR images. We obtained exercise history and measured physical fitness and body composition. Equivalent ele…
Differential role of interleukin-1β in neuroinflammation-induced impairment of spatial and nonspatial memory in hyperammonemic rats.
2019
Activated microglia and increased brain IL-1β play a main role in cognitive impairment in much pathology. We studied the role of IL-1β in neuroinflammation-induced impairment of the following different types of learning and memory: novel object recognition (NOR), novel object location (NOL), spatial learning, reference memory (RM), and working memory (WM). All these processes are impaired in hyperammonemic rats. We assessed which of these types of learning and memory are restored by blocking the IL-1 receptor in vivo in hyperammonemic rats and the possible mechanisms involved. Blocking the IL-1 receptor reversed microglial activation in the hippocampus, perirhinal cortex, and prefrontal cor…
Maternal inflammation has a profound effect on cortical interneuron development in a stage and subtype-specific manner
2018
AbstractSevere infections during pregnancy are one of the major risk factors for cognitive impairment in the offspring. It has been suggested that maternal inflammation leads to dysfunction of cortical GABAergic interneurons that in turn underlies cognitive impairment of the affected offspring. However, the evidence comes largely from studies of adult or mature brains and how the impairment of inhibitory circuits arises upon maternal inflammation is unknown. Here we show that maternal inflammation affects multiple steps of cortical GABAergic interneuron development, i.e., proliferation of precursor cells, migration and positioning of neuroblasts, as well as neuronal maturation. Importantly,…
Social stress during adolescence activates long-term microglia inflammation insult in reward processing nuclei
2018
The experience of social stress during adolescence is associated with higher vulnerability to drug use. Increases in the acquisition of cocaine self-administration, in the escalation of cocaine-seeking behavior, and in the conditioned rewarding effects of cocaine have been observed in rodents exposed to repeated social defeat (RSD). In addition, prolonged or severe stress induces a proinflammatory state with microglial activation and increased cytokine production. The aim of the present work was to describe the long-term effects induced by RSD during adolescence on the neuroinflammatory response and synaptic structure by evaluating different glial and neuronal markers. In addition to an inc…