Instituto Interuniversitario de Neurociencias de Castilla y León (INCyL)

Performance assessment of no-fee GNSS augmentation systems for tractor guidance

Tue, 24 Mar 2026 00:00:00 GMT

[EN] This study assesses the performance of no-fee GNSS augmentation systems for tractor guidance. Five no-fee augmentation systems: EGNOS, GLIDE, RTK, VRS-NRTK, and on-site RTK were evaluated in both static and guidance tests over short- and long‑term periods using three GNSS receiver types: low-cost Navilock NL8022MP, mid-range Novatel Smart2, and high-end Harxon TS108PRO. Static tests recorded 24 h of position data from 14 receiver-augmentation configurations on a fixed surface. Guidance tests recorded trajectory data from the 14 configurations during straight-line guidance using a tractor equipped with two GNSS receivers, one under test and one high-precision reference. Results found that: (i) unaugmented GNSS resulted in guidance errors of 2–3 m, reduced below 1 m in pass-to-pass intervals shorter than 15 min; (ii) EGNOS reduced these guidance errors by ∼41%; (iii) GLIDE reduced guidance errors to below 20 cm for pass-to-pass intervals shorter than 15 min, with no long-term improvement; (iv) RTK guidance error decreased as baseline length shortened: >100 km yielded > 17 cm, 20–100 km yielded 3–20 cm, and < 20 km yielded 2–3 cm; (v) VRS-NRTK slightly outperformed RTK with similar baseline lengths; and (vi) on-site RTK enabled 1 cm guidance error. In summary: low-cost receivers without augmentation or with EGNOS result in metre-level errors; mid-range receivers with GLIDE deliver decimetre-level guidance errors in the short term; and high-end receivers using on-site RTK or VRS-NRTK on baselines up to 100 km achieve centimetre-level errors, enabling farmers to replicate tractor trajectories consistently year to year.

Multisession epidural direct current stimulation of the auditory cortex mitigates age-related transcriptomic dysregulation in Wistar rats

Thu, 19 Feb 2026 00:00:00 GMT

[EN]Age-related hearing loss (ARHL) disrupts ascending auditory inputs, impairing auditory signal transmission, triggering cortical hyperexcitability, and increasing the risk of age-related cognitive decline. In early aging, multisession epidural direct current stimulation (DCS) of the auditory cortex (AC) preserves auditory thresholds and prevents cortical hyperexcitability in Wistar rats. Here, we hypothesized that multisession DCS could halt transcriptional dysregulation in the AC at the earliest stages of aging. We have characterized age-related transcriptional changes in the AC to assess DCS-mediated effects by RNA-seq. At 18.13 months, non-stimulated, aged rats (NES) showed 194 differentially expressed genes (DEGs) in relation to young controls (YG), with enrichment in pathways associated with GABAergic, glutamatergic, and dopaminergic synapses, long-term potentiation/depression, inflammaging, autophagy, apoptosis and neurodegeneration. The upregulated genes included Gabrb1, Grin2b, Rac3c, Tnr, and Ndst1, suggesting compensatory hyperactivity, excitatory/inhibitory imbalance, and stiffening of perineuronal nets (PNN) around parvalbumin (PV) interneurons. Electrically stimulated (ES) rats showed 86 DEGs in relation to YG, with no significant enrichment in aging-related pathways. By contrast, NES vs ES showed 1393 DEGs, with strong enrichment in aging-related pathways. Also, many of the 121 common DEGs across comparisons, which are upregulated in NES and downregulated in ES, are related to neurotransmission (Gabrb1, Grin2b), synaptic scaffolding (Dlg2, Prkca), trophic signaling (Ntrk2, Igf1r) and PNN (Tnr, Ndst1). Based on these findings, multisession DCS curbs maladaptive genomic reprogramming in the aged AC most likely by preserving excitatory/inhibitory balance and maintaining PNN integrity, thereby protecting the AC from ARHL and cognitive vulnerability.

Sex- and etiology-specific effects on predictive processing in the inferior colliculus of two rat models of autism

Fri, 30 Jan 2026 00:00:00 GMT

[EN] Atypical sensory processing is a common feature of autism, yet the neural computations that give rise to these differences, particularly in relation to biological sex and etiological origin, remain unclear. Here we examine predictive auditory processing at the single-neuron level in the inferior colliculus of two adult rat models of autism: a genetic model with a heterozygous Grin2b deletion (Grin2b + /-) and an environmental model based on prenatal valproic acid exposure. We recorded neuronal responses to an auditory oddball paradigm and a cascade control sequence across lemniscal and non-lemniscal IC divisions under high-intensity stimulation, allowing us to derive indices of repetition suppression, prediction error and neuronal mismatch. Using generalized linear mixed-effects models that accounted for animal identity, inferior colliculus division, sex, and rat model, followed by hierarchical group-level comparisons, we identified robust alterations in predictive processing in both autism-like models. These effects varied across inferior colliculus divisions and differed between sexes, revealing distinct phenotype-specific signatures. The results indicate that sex and etiology jointly modulate early auditory computations in autism. More broadly, our findings highlight the translational value of predictive coding frameworks and support the use of complementary animal models to capture neurobiological heterogeneity across the autism spectrum

Prosodia rítmico frecuencial en lingüística clínica: en búsqueda de biomarcadores fonéticos para alzheimer y depresión mayor

Wed, 01 Jan 2025 00:00:00 GMT

[EN]This paper delves into the prosodic features of speech affected in AD and MD, the type of pathology they are associated with (aphasia, apraxia or aprosodia), as well as the contribution of these alterations to the neurolinguistic field (hemispheric specialization).We used a corpus of spontaneous speech from patients with AD (n=10) and MD (n=10), and a control group with HS (n=10). The results showed a discriminatory significance of VnPVI (in MD), and (Δ)f0 and %V; furthermore, %V is a strong variable to distinguish between speakers with and without pathology, as well as to discriminate between AD and MD along with other variables. There is, however, no correlation with verbal fluency (semantic and phonological) or with MMSE, which would imply a motor type deficit: apraxic type in AD and aprosodic type in MD. These results show certain phonological and typological conditioning, among other issues.

Auditory deviance detection beyond the auditory pathway: Hierarchical predictive coding in the hippocampus and primary visual cortex

Thu, 01 Jan 2026 00:00:00 GMT

[EN] Under the predictive coding framework, perception is understood as an inferential process in which the brain continuously generates predictions about incoming sensory input and updates its internal models when reality deviates from expectation. Auditory deviance detection provides a tractable paradigm to investigate how the brain encodes prediction errors. While these computations are well characterized within the auditory hierarchy, their extension to memory-related and cross-modal structures remains unclear. This thesis examines auditory predictive processing beyond the auditory pathway, focusing on the hippocampus and the primary visual cortex (V1) as potential nodes in a distributed predictive network. Using extracellular recordings in urethane-anesthetized rats, I measured single- and multi-unit activity and local field potentials (LFPs) from hippocampal subfields (dentate gyrus [DG], cornu ammonis 1 [CA1]) and infragranular layers (IV–VI) of V1. Classical oddball paradigms and no-repetition control sequences were employed to dissociate repetition suppression from genuine prediction error components. Approximately one-fifth of hippocampal neurons responded to auditory stimulation, with a subset (~20%) showing enhanced activity to deviant tones. DG neurons displayed shorter latencies and larger mismatch and prediction error indices than CA1, suggesting a distinct contribution to novelty-related processing. Spiking responses reflected prediction error, while LFPs showed distinct contributions from repetition suppression and prediction error that varied across subfields. Early LFP components were enhanced for randomly presented deviants, whereas later components were more pronounced for predictable deviants. In V1, more than half of infragranular neurons responded to tones despite the absence of visual input, 50% showing larger responses to deviant than standard stimuli. These responses predominantly reflected prediction error rather than adaptation and were amplified under temporally uncertain (random) conditions. Layer V neurons exhibited rapid, phasic responses, whereas layer VI responses were broader and more sustained, consistent with laminar specialization in hierarchical predictive coding. Together, these results demonstrate that auditory prediction errors are encoded in both hippocampal and visual circuits, extending predictive processing beyond classical sensory boundaries, positioning both regions as integral components of a distributed predictive coding architecture that underlies hierarchical inference across the brain.

Binaural audio processing to improve speech in noise intelligibility: Design and experimental evaluation with normal-hearing listeners and hearing-aid users

Thu, 01 Jan 2026 00:00:00 GMT

[EN] Understanding speech in noisy environments remains challenging for individuals with hearing loss, particularly in listening scenarios involving multiple competing sound sources. While modern hearing aids incorporate directional microphones and noise reduction methods, their effectiveness is limited by assumptions about the acoustic scene or by the degradation of spatial cues in users of bilateral devices. Current approaches, such as adaptive beamforming or machine learning-based source separation, rely on complex estimations of the location or the characteristics of the target sound. Furthermore, they often require multiple microphones per device or synchronized bilateral processing. These constraints limit their applicability and leave many users with suboptimal performance in multi-talker environments. In this thesis, we present a binaural audio processing method designed to improve speech intelligibility in noisy environments by attenuating contralateral sounds. The method consists of subtracting a weighted version of the contralateral signal from the ipsilateral signal. It operates in the frequency domain, with subtraction weights based on generic head-related transfer functions, and without requiring prior knowledge of the target or noise properties or their location. The method is first evaluated using objective metrics in simulated listening scenarios. Results demonstrate consistent improvements in the signal-to-noise ratio and the short-term objective intelligibility, particularly for spatially separated target and noise sources. These findings confirm the theoretical premise that contralateral sound attenuation can improve speech intelligibility without the need for complex spatial analysis or source tracking. The method is then evaluated experimentally on individuals with normal hearing as well as in users of bilateral hearing aids. In normal-hearing listeners, the method improved intelligibility in unilateral listening but was less effective in bilateral listening due to its altering spatial cues. Hearing-aid users exhibited substantial improvements in both unilateral and bilateral listening, underscoring the method’s potential to compensate for degraded binaural processing. Overall, the findings support the effectiveness and practical relevance of the proposed method. Its simplicity and low computational cost make it a promising candidate for implementation in hearing technologies. The thesis contributes a novel sound processing method for speech enhancement that addresses real-world auditory challenges faced by individuals with and without hearing loss.

The impact of "hidden" hearing loss, reduced inhibition of cognitive interference, and aging on behavioral adaptation to noise

Thu, 01 Jan 2026 00:00:00 GMT

[EN] Understanding speech in noisy environments is challenging but essential for human verbal communication. Fortunately, the auditory system can adapt to background noise, which facilitates speech intelligibility in noisy environments. Behavioral adaptation to noise, however, varies across individuals for reasons that are unclear. The aim of the work presented in this thesis was to investigate whether behavioral adaptation to noise is affected by ‘hidden’ hearing loss (HHL), a reduced ability to inhibit cognitive interference, or aging. Eighty-nine adult speakers of Castilian Spanish (19–86 years old) with clinically normal hearing participated in the experiments. Speech reception thresholds (SRTs), the signal-to-noise ratio at 50 % recognition, were measured for disyllabic words embedded in noise. SRTs were measured for words delayed 50 ms and 800 ms in the noise, for various noises and levels. Adaptation to noise was calculated as the improvement in the long-delay relative to the short-delay condition. Because adaptation is greater for vocoded than for natural words, words were processed through a tone vocoder. The risk of HHL was assessed using the amplitude and the rate of growth (slope) of wave I of the auditory brainstem response (ABR). The ability to inhibit cognitive interference was assessed using the Stroop color and word test. The data revealed that participants exhibited significant adaptation to noise, and that adaptation was greater at higher noise levels and for steady than for fluctuating noises. However, adaptation was not significantly associated with ABR wave I amplitude or slope, age, or Stroop test score, even after controlling for the potential confounding effect of audiometric threshold. Findings suggest that behavioral adaptation to noise is preserved across the adult lifespan and is independent of subclinical auditory deficits or inhibitory control abilities. Findings further suggest that speech-in-noise difficulties experienced by older adults or individuals at risk of suffering from HHL should be attributed to factors other than impaired adaptation to noise.

Anatomía y fisiología del hipotálamo de la oveja, implicaciones en la regulación de la estacionalidad reproductiva

Wed, 01 Jan 2025 00:00:00 GMT

[ES] El presente trabajo de tesis doctoral surge de la necesidad de la búsqueda, en nuestro modelo experimental (oveja Churra), de procedimientos para la evaluación de intervenciones o experimentos enfocados a modificar la estacionalidad y la fertilidad. En este sentido, este trabajo tiene la relevancia de ampliar los conocimientos y las técnicas aplicadas a un campo, el de la producción animal, de la neurociencia. En los últimos años, en el grupo de producción animal de la universidad de Salamanca, a cargo del Prof. Palacios Riocerezo, se han desarrollado proyectos enfocados a la modificación de la estacionalidad mediante cambios en el fotoperiodo, tratamiento hormonales y comportamentales. Los análisis de las variaciones hormonales en sangre sirven de mucha ayuda para estos fines, pero nuestro grupo detectó que el cambio estacional en la oveja se produce en un espacio de tiempo relativamente amplio y difícil de detectar en sus orígenes debido al carácter pulsátil de la liberación de GnRH. Nuestro planteamiento, por tanto, fue que el estudio de los núcleos hipotalámicos con inmunocitoquimica puede permitir un diagnóstico de certeza del cambio estral en nuestras intervenciones. Sin embargo, localizar los núcleos hipotalámicos y su anatomía funcional (inmunocitoquímica) es tarea difícil en una especie (oveja churra) no bien caracterizada anatómicamente. Por ello tuvimos que estudiar primero la anatomía del diencefalo de nuestro modelo (oveja churra) que se publicó en el año 2023 (Merchán M Jr, Coveñas R, Plaza I, Abecia JA, Palacios C. Anatomy of hypothalamic and diencephalic nuclei involved in seasonal fertility regulation in ewes. Front Vet Sci. 2023 Feb 16;10:1101024. doi: 10.3389/fvets.2023.1101024. PMID: 36876003; PMCID: PMC9978410) Q1. Los siguientes pasos fueron dirigidos directamente al propósito de nuestra hipótesis de partida: determinar un proceso objetivo de valoración de la activación estral del hipotálamo. Para ello evaluamos primero con detalle la distribución y cuantificación de la GnRH en un segundo articulo: Merchán M Jr, Plaza I, Nieto J, Plaza J, Abecia JA, Palacios C. Densitometric analysis of GnRH and IBA1 immunocytochemistry in the basal ventromedial hypothalamus of the ewe. Theriogenology. 2024 Oct 1;227:112-119. doi: 10.1016/j.theriogenology.2024.07.012. Epub 2024 Jul 21. PMID: 39053287 Q1. En este articulo demostramos la importancia de valorar la actividad paracrina de la GnRH en relación con la regulación de la microglía inmunoreactiva para esta hormona. Se definió así un procedimiento objetivo que permite la aplicación de morfometría para correlacionar los cambios hormonales y la activación hipotalámica. El tercer artículo, en curso, sobre "Validación inmunocitoquímica de la activación estrogénica hipotalámica de GnRH localizada en el núcleo arcuato de la oveja" (Experiencia 3 en el manuscrito) trata de ser una aplicación práctica de la correlación planteada en nuestra hipótesis de partida. En resumen, nos gustaría enfatizar que este trabajo no solo está enfocado al mejor conocimiento del diencéfalo de la oveja sino más bien a la búsqueda criterios objetivos para evaluar los cambios estrales y la fertilidad vinculado al campo de la producción animal. Abordar este trabajo desde la síntesis de los conocimientos de ámbitos no próximos en los campos de conocimiento como la neurociencia y la producción animal ha resultado en un esfuerzo sustancial. Sin embargo, esperamos que permita en el futuro hacer estas técnicas accesibles a los investigadores del campo de la Ingeniería agrícola en nuestro entorno mas proximo

Dataset of Oddball Paradigm experiment in the Auditory Cortex and the effect of acetylcholine

Sat, 10 Jan 2026 00:00:00 GMT

[EN]This work presents three open datasets featuring various levels of processing, containing neural recordings from the auditory cortex of rats. These recordings were obtained during experiments using the auditory oddball paradigm before, during and after the local microiontophoretic application of acetylcholine. The primary objective of these datasets is to investigate how the brain processes predictable versus unexpected auditory stimuli, and the role of cholinergic inputs during such processing. The data include multi-unit recordings of neuronal activity during the presentation of standard and deviant tones, classified by stimulus type and cortical sub-region. These resources enable quantitative investigations of deviance detection, stimulus-specific adaptation, cholinergic modulation and predictive-coding mechanisms at multiple temporal scales.

Melatonin at the Crossroads of Oxidative Stress, Immunity, and Cancer Therapy

Sat, 03 Jan 2026 00:00:00 GMT

[EN] Melatonin, an ancient and evolutionarily conserved indolamine, has long attracted attention for its multifunctional roles in redox homeostasis. More recently, it has been studied in relation to immune regulation and cancer biology. Beyond its well-known circadian function, melatonin modulates oxidative stress by directly scavenging reactive oxygen and nitrogen species and by upregulating antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase. At the same time, it exerts wide-ranging immunomodulatory functions by influencing both innate and adaptive immune responses. All these actions converge within the tumor microenvironment, where oxidative stress and immune suppression drive cancer progression. Although the antitumoral effects of melatonin have traditionally been interpreted through its actions on T cells and NK cells, recent studies identify macrophages as an underappreciated and pivotal target. Notably, melatonin influences macrophage polarization, favoring antitumor M1 phenotypes over pro-tumoral M2 states, while attenuating chronic inflammation and restoring mitochondrial function. This review summarizes current knowledge on melatonin’s antioxidant and immunoregulatory mechanisms, highlighting its impact on the tumor immune microenvironment, with a particular focus on the growing recognition of macrophages as a compelling new axis through which melatonin may exert anticancer effects

Advancing urine‐derived stem cells: Cryopreservation validation and sex‐specific metabolism

Mon, 26 Jan 2026 00:00:00 GMT

[EN] Background: Urine-derived stem cells (UDSC) are an emerging, non-invasive source of human stem cells combining easy collection, broad accessibility and high patient compliance with multilineage differentiation capacity. However, key gaps remain in UDSC research, particularly in understanding sex-related differences and the lack of a validated cryopreservation protocol, a critical aspect for primary cells, given their variability in colony formation, proliferation rates and experimental timing. To address these limitations, this study aimed to establish, for the first time, a reliable protocol for UDSC cryopreservation and to explore potential sex-related differences, with a specific focus on glycolysis and mitochondrial respiration. Methods: UDSC were isolated from urine samples of healthy donors (aged 27–50, 4 males and 4 females), cultured in 1:1 DMEM:KSFM supplemented with 10% fetal bovine serum and cryopreserved at passages 2–4 using the same medium with the sole addition of 5% dimethyl sulfoxide. Cells were evaluated for viability, apoptosis/necrosis, metabolic profile and multilineage differentiation potential. Comparisons were performed based on donor sex, as well as before and after cryopreservation. Results: Male- and female-derived UDSC displayed no significant differences in viability and cell death or metabolic profile. Moreover, supervised and unsupervised machine learning methods were unable to discriminate between the two groups, allowing for pooled data analysis and improved statistical power. Similarly, fresh and cryopreserved UDSC displayed comparable viability, metabolic activity and multilineage differentiation relative to fresh cells, with no detectable differences in computational analyses. Conclusions: These findings support UDSC adoption for biobanking, disease modelling and regenerative medicine.

Estudio del sistema nitrérgico y del equilibrio excitación/inhibición en el bulbo olfativo de un modelo experimental de autismo idiopático

Wed, 01 Jan 2025 00:00:00 GMT

[ES] La búsqueda de conocimiento sobre el autismo constituye un importante desafío para la comunidad científica y para la sociedad. A pesar del esfuerzo y de las numerosas investigaciones al respecto, todavía no están claras las características fisiopatológicas de este trastorno del neurodesarrollo. Así, aunque se ha avanzado en su comprensión, sigue habiendo numerosas cuestiones por resolver sobre su naturaleza precisa. Mediante la investigación básica se pretende arrojar luz sobre los intrincados mecanismos que subyacen al autismo, sobre sus bases moleculares, celulares, neuroanatómicas y conductuales. En base a la evidencia científica disponible, se sabe que el desequilibrio entre la neurotransmisión excitatoria y la inhibitoria es clave en la patogenia del autismo. Al mismo tiempo, se ha propuesto una alteración en el sistema nitrérgico, agente modulador del equilibrio entre los tipos de actividad sináptica mencionados. En esta Tesis Doctoral se estudiaron los sistemas nitrérgico, GABAérgico y glutamatérgico en el bulbo olfativo del modelo murino de autismo inducido por ácido valproico (VPA). En primer lugar, se desarrolló un protocolo optimizado para obtener el ratón VPA, atendiendo a los procesos de inducción y de validación del modelo. En segundo lugar, se registraron déficits nitrérgicos en la región cerebral de interés. Finalmente, los análisis en torno a la excitabilidad sináptica revelaron una descompensación en la neurotransmisión por afectación de la vía glutamatérgica. En el marco de las alteraciones neuronales inherentes al autismo, estos resultados ponen de manifiesto diversas desregulaciones en los sistemas de neurotransmisión/neuromodulación analizados y complejas dinámicas resultantes de su interrelación.

HSP25 and HSP25-P-Ser15 Prompt Innate Neuroprotection in Lobe X of the Cerebellum

Thu, 01 Jan 2026 00:00:00 GMT

[EN]The cerebellar cortex presents a repetitive structure, but the main projecting neurons of this tissue, the Purkinje cells, are not identical and behave differently to various types of injury. Common patterns of neurodegeneration exist, where certain Purkinje cells die earlier than others. By contrast, lobe X of the cerebellum is a particularly resistant structure, independently of the cerebellar disease or damage. However, the mechanisms underlying the survival capability of these especially resistant Purkinje cells are still unknown. In this work, we have used the Purkinje Cell Degeneration (PCD) mouse, a model of severe cerebellar degeneration that also reproduces the human disease called childhood-onset neurodegeneration with cerebellar atrophy, to study Purkinje cell resistance. After an exhaustive immunochemical analysis of the different subpopulations of Purkinje cells, the Heat Shock Protein 25 (HSP25) and its phosphorylated version HSP25-P-Ser15 were found to be especially induced in lobe X of PCD mice. As this protein has neuroprotective properties, it may be responsible for resistance against cerebellar neurodegeneration. Taking into account the constant resistance of lobe X, the use of HSP25 may lead to new possibilities for achieving natural protection both in cerebellum and in other brain structures, or even for developing future neuroprotective therapies.

Neuronal mismatch responses to auditory stimuli in the dorsal hippocampus of anesthetized rats

Wed, 24 Dec 2025 00:00:00 GMT

[EN] The hippocampus is classically linked to memory, yet increasing evidence points to a broader role in perceptual inference and deviance detection. Predictive coding theories propose that perception minimizes mismatches between expected and actual sensory input, expressed in neural signatures such as mismatch negativity (MMN) and P300. Although MMN arises mainly from sensory and prefrontal cortices, the hippocampus is anatomically interconnected with both and may also contribute to prediction error processing. We recorded single- and multi-unit activity and local field potentials (LFPs) from DG and CA1 in urethane-anesthetized rats during an auditory oddball paradigm and a no-repetition control sequence to dissociate prediction error from repetition suppression. Approximately 20% of hippocampal neurons were sound responsive, and a subset showed deviant selectivity. Spiking activity predominantly reflected prediction errors, while LFPs revealed complementary contributions from repetition suppression and prediction error. Early LFP components were enhanced for randomly presented deviants, whereas later components within the P300 latency range were stronger for predictable deviants, indicating temporally distinct phases of error signaling and top-down modulation. These findings identify the hippocampus as an active contributor to auditory deviance detection and support a hierarchical model in which hippocampal circuits participate in predictive sensory processing beyond memory.

Model of selective neurodegeneration driven by a Ccp1 mutation leads to atypical microglia with an increased response to pathological stimuli

Tue, 07 Jan 2025 00:00:00 GMT

Microglia are the primary immune cells of the central nervous system and maintain tissue homeostasis through phagocytosis and regulation of inflammatory signalling. Although these functions are well established, the molecular mechanisms that control microglial activation during neurodegeneration remain poorly understood. We focused on the Purkinje Cell Degeneration (PCD) mouse, which carries a loss-of-function mutation in Ccp1 that disrupts tubulin post-translational modifications essential for cytoskeletal stability. Because cytoskeletal dynamics are fundamental for microglial motility, phagocytosis, and proliferation, the Ccp1 mutation offers a model to directly examine how intrinsic cytoskeletal defects alter microglial behaviour and how these alterations manifest within regions undergoing distinct patterns of neurodegeneration. To this end, we combined in vitro and in vivo approaches. Microglia were isolated from neonatal cortex and adult cerebellum and olfactory bulb, and microglia-like cells were generated from bone marrow-derived haematopoietic stem cells. In vivo microglial depletion was achieved with the CSF1R inhibitor PLX5622. Immunohistochemistry quantified microglial density, morphology, and marker expression; transcriptomic profiling assessed identity and functional pathways; and functional assays evaluated phagocytosis, motility, and proliferation. Motor behaviour tests were performed to determine whether microglial dysfunction contributes to circuit-level impairments. Statistical analyses used parametric or non-parametric tests according to distribution. Ccp1-deficient microglia exhibited intrinsic deficits in phagocytosis, motility, and proliferation, independent of overt neuronal loss. These impairments were amplified in degenerating regions, where microglia adopted a predominantly anti-inflammatory rather than pro-inflammatory activation profile. This atypical state suggests a maladaptive response that may compromise tissue homeostasis and intensify disease progression. Consistent with this, animals showed altered motor behaviour, indicating functional consequences of microglial dysfunction. Together, these findings identify Ccp1 as a key regulator of microglial homeostasis and demonstrate how cytoskeletal disruption can reshape microglial responses in neurodegenerative environments, providing mechanistic insight and potential therapeutic targets.

Nucleolin reorganization and nucleolar stress in Purkinje cells of mutant PCD mice.

Mon, 01 Jul 2019 00:00:00 GMT

[EN] The Purkinje cell (PC) degeneration (pcd) mouse harbors a mutation in Agtpbp1 gene that encodes for the cytosolic carboxypeptidase, CCP1. The mutation causes degeneration and death of PCs during the postnatal life, resulting in clinical and pathological manifestation of cerebellar ataxia. Monogenic biallelic damaging variants in the Agtpbp1 gene cause infantile-onset neurodegeneration and cerebellar atrophy, linking loss of functional CCP1 with human neurodegeneration. Although CCP1 plays a key role in the regulation of tubulin stabilization, its loss of function in PCs leads to a severe nuclear phenotype with heterochromatinization and accumulation of DNA damage. Therefore, the pcd mice provides a useful neuronal model to investigate nuclear mechanisms involved in neurodegeneration, particularly the nucleolar stress. In this study, we demonstrated that the Agtpbp1 gene mutation induces a p53-dependent nucleolar stress response in PCs, which is characterized by nucleolar fragmentation, nucleoplasmic and cytoplasmic mislocalization of nucleolin, and dysfunction of both pre-rRNA processing and mRNA translation. RT-qPCR analysis revealed reduction of mature 18S rRNA, with a parallel increase of its intermediate 18S-5'-ETS precursor, that correlates with a reduced expression of Fbl mRNA, which encodes an essential factor for rRNA processing. Moreover, nucleolar alterations were accompanied by a reduction of PTEN mRNA and protein levels, which appears to be related to the chromosome instability and accumulation of DNA damage in degenerating PCs. Our results highlight the essential contribution of nucleolar stress to PC degeneration and also underscore the nucleoplasmic mislocalization of nucleolin as a potential indicator of neurodegenerative processes.