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Aiello, G.

Publications and source records attributed to Aiello, G..

4 recordsLinked to original sources

Sleep spindles stabilize human thalamocortical networks, inhibiting pathological disruptions

The thalamus coordinates sleep-dependent brain function including memory consolidation, sensory gating, and network stability through spindle oscillations. Thalamocortical circuits are also affected in many neurological and neuropsychiatric disorders. Yet how human thalamocortical circuits respond to pathological disruptions remain poorly understood. Here, we leveraged interictal epileptiform discharges (IEDs) as spontaneous perturbations to probe spindle-generating circuits and thalamocortical dynamics in vivo. Using multi-night intracranial recordings spanning multiple thalamic nuclei and cortical regions in 55 individuals with epilepsy, we investigated interactions between sleep spindles and epileptic activity across timescales from milliseconds to days. Sleep spindles were associated with IED suppression, whereas IEDs increased subsequent spindle probability, revealing bidirectional interactions between physiological and pathological activity. Nights with lower IEDs corresponded to increased spindle occurrence, longer duration, and faster frequency, reflecting a more stable thalamocortical state. These findings propose sleep spindles as potential regulators of thalamocortical networks that actively respond to and regulate pathological activity.

neuroscience↗

Increased Reproducibility of Brain Organoids through Controlled Fluid Dynamics

Brain organoids are a promising model for studying human neurodevelopment and disease. Despite the potential, their 3D structure often exhibits high variability during differentiation across batches and cell lines, presenting a significant challenge for biomedical applications. During their development, organoids are exposed to fluid flow shear stress (fFSS) generated by the flow of culture media over the developing tissue. This stress is thought to disrupt cellular integrity and morphogenesis, leading to variation in organoids architecture, ultimately affecting reproducibility. Understanding the interplay between tissue morphology, cell identity and organoid developmental stage is therefore essential for advancing the use of brain organoids. Here, we demonstrate that reducing fFSS, by employing a vertically rotating chamber during neuronal induction, a critical phase for organoid morphogenesis, along with an extended human induced pluripotent stem cell (hiPSC) aggregation phase to minimize fusions, significantly improves the reproducibility of brain organoids. Remarkably, reducing fFSS minimized morphological structure variation and preserved transcriptional signature fidelity across differentiation batches and cell lines. This approach could enhance the reliability of brain organoid models, with important implications for neurodevelopmental research and preclinical studies.

neuroscience↗

The m6A reader Ythdf restricts axonal growth in Drosophila through target selection modulation of the Fragile X mental retardation protein

N6-methyladenosine (m6A) regulates a variety of physiological processes through modulation of RNA metabolism. The modification is particularly enriched in the nervous system of several species, and its dysregulation has been associated with neurodevelopmental defects and neural dysfunctions. In Drosophila, loss of m6A alters fly behavior albeit the underlying mechanism and the role of m6A during nervous system development have remained elusive. Here we find that impairment of the m6A pathway leads to axonal overgrowth and misguidance at larval neuromuscular junctions as well as in the adult mushroom bodies. We identify Ythdf as the main m6A reader in the nervous system being required for limiting axonal growth. Mechanistically, we show that Ythdf directly interacts with Fragile X mental retardation protein to inhibit the translation of key transcripts involved in axonal growth regulation. Altogether, this study demonstrates that the m6A pathway controls development of the nervous system by modulating Fmr1 target selection.

molecular biology↗

Screening of Tau Protein Kinase Inhibitors in a Tauopathy-relevant cell-based model of Tau Hyperphosphorylation and Oligomerization

Tauopathies are a class of neurodegenerative disorders characterized by abnormal deposition of post-translationally modified tau protein in the human brain. Tauopathies are associated with Alzheimers disease (AD), chronic traumatic encephalopathy (CTE), and other diseases. Hyperphosphorylation increases tau tendency to aggregate and forms neurofibrillary tangles (NFT), a pathological hallmark of AD. In this study, okadaic acid (OA, 100 nM), a protein phosphatase 1/2A inhibitor, was treated for 24h in mouse neuroblastoma (N2a) and differentiated rat primary neuronal cortical cell cultures (CTX) to induce tau-hyperphosphorylation and oligomerization as a cell-based tauopathy model. Following the treatments, the effectiveness of different kinase inhibitors was assessed using the tauopathy-relevant tau antibodies through tau-immunoblotting, including the sites: pSer202/pThr205 (AT8), pThr181 (AT270), pSer202 (CP13), pSer396/pSer404 (PHF-1), and pThr231 (RZ3). OA-treated samples induced tau phosphorylation and oligomerization at all tested epitopes, forming a monomeric band (46-67 kDa) and oligomeric bands (170 kDa and 240 kDa). We found that TBB (a casein kinase II inhibitor), AR and LiCl (GSK-3 inhibitors), cyclosporin A (calcineurin inhibitor), and Saracatinib (Fyn kinase inhibitor) caused robust inhibition of OA-induced monomeric and oligomeric p-tau in both N2a and CTX culture. Additionally, a cyclin-dependent kinase 5 inhibitor (Roscovitine) and a calcium chelator (EGTA) showed conflicting results between the two neuronal cultures.This study provides a comprehensive view of potential drug candidates (TBB, CsA, AR, and Saracatinib), and their efficacy against tau hyperphosphorylation and oligomerization processes. These findings warrant further experimentation, possibly including animal models of tauopathies, which may provide a putative Neurotherapy for AD, CTE, and other forms of tauopathy-induced neurodegenerative diseases.

neuroscience↗