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Category: neuroscience

Open 3D Human Organ Atlas lets users explore anatomy in unprecedented detail

An international team of scientists and clinicians has announced the launch of a new open-access 3D portal that allows users to explore intact human organs in unprecedented detail—from the whole organ down to individual cells locally. The Human Organ Atlas, created using a powerful synchrotron imaging method, brings together some of the most detailed 3D images of human organs ever produced. It enables scientists, doctors, educators, students and the wider public to interactively “fly through” organs such as the brain, heart, lungs, kidney and liver, providing a new way of understanding human anatomy and human diseases.

Building on an initial release, the Human Organ Atlas (HOA) is now available in a greatly expanded form and can be accessed directly through a standard web browser, without specialized software. The technology is published in the journal Science Advances.

The Atlas is powered by an advanced imaging method called Hierarchical Phase-Contrast Tomography (HiP-CT), developed at the European Synchrotron (ESRF) in Grenoble, France, by an international team led by University College London (UCL), UK. HiP-CT uses the ESRF’s Extremely Brilliant Source—a new generation of synchrotron source—which is up to 100 billion times brighter than conventional hospital CT scanners.

Dendrite-Targeting Inhibitory Interneurons Form Biased Circuits with Deep and Superficial Pyramidal Cells in Hippocampal CA1

JNeurosci: Johantges et al. used mice to study excitatory and inhibitory synaptic connections in the CA1 region, creating a circuit map with cell-type resolution that will guide future research on how the hippocampus supports learning and memory.

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In the CA1 hippocampus, pyramidal cells (PCs) can be classified as deep or superficial based on their radial position within the stratum pyramidale. Deep and superficial PCs form biased circuits with perisomatic-targeting PV+ basket cells, but it is unknown if such cell-type–specific circuit motifs extend to dendrite-targeting interneurons. Using male and female mice, we investigated synaptic connectivity and physiology in brain slices from four transgenic lines thought to capture distinct subsets of interneurons: SST-IRES-Cre, Nkx2.1-Cre, Chrna2-Cre, and Htr3a-GFP. First, we found that oriens-lacunosum moleculare (OLM) cells captured by the Chrna2-Cre line are a subset of Htr3a-GFP+ cells in the hippocampus. This novel finding is consistent with previous work showing Nkx2.1-Cre OLM cells are distinct from both Chrna2-Cre and Htr3a-GFP+ OLM cells.

Clinical Reasoning: A 49-Year-Old Man With Meningoencephalitis and Persistent Altered Mental Status

Cannabis use is common among those with mental health conditions, and many people report using cannabis to manage mental health symptoms.

It is important for clinicians to understand the lack of clear benefits of cannabis for mental health conditions and the potential for substantial adverse effects.

📌 This Review summarizes the current evidence on the effects of cannabis on commonly encountered mental health conditions and provides clinicians with basic information about cannabis pharmacology and biology.

Tubulin prevents toxic protein clump formation

“This led us to the following idea: what if instead of preventing the formation of droplets, we created conditions that would drive Tau and alpha synuclein inside the droplets toward their healthy path, discouraging them from taking the disease path?” said a co-corresponding author of the work.

The team worked with biochemical and biophysical techniques, high-resolution microscopy and neuronal-based assays to investigate tubulin’s role in modulating and preventing the formation of toxic aggregates in droplets.

The researchers show that Tubulin modulates Tau:αSyn condensates by promoting microtubule interactions and inhibiting homotypic and heterotypic pathological oligomers. Tubulin partitioning into condensates promotes microtubule polymerization and prevents Tau and αSyn oligomerization.

In the absence of Tubulin, Tau-driven condensation accelerates formation of pathogenic Tau:αSyn heterodimers and amyloid fibrils. The authors also identify distinct Tau and αSyn structural states in pathological Tubulin-absent versus physiological Tubulin-rich condensates.

“When tubulin levels are low, as it has been found in Alzheimer’s disease, microtubules are less abundant and Tau and alpha synuclein can form toxic aggregates,” the author said. “But when tubulin is present, Tau and alpha‑synuclein shift away from harmful aggregates and instead promote the assembly of healthy microtubules,” the author said. “Tubulin redirects the activity of these proteins by giving them something productive to do.” ScienceMission sciencenewshighlights.

Researchers have discovered a potential new strategy to fight back against Alzheimer’s and Parkinson’s diseases, conditions that are linked to the toxic accumulation of Tau and alpha synuclein protein clumps in the brain. The team reports in Nature Communications that tubulin, the building block of microtubules, the cell’s internal ‘railway tracks,’ can stop Tau and alpha synuclein from forming toxic clumps and instead steer them into their normal, healthy roles.

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