Search Results (537)

Among brain regions, the cerebellum (CBL) has traditionally been associated with motor control. However, increasing evidence from connectomics and functional imaging has expanded this view, revealing its involvement in a wide range of cognitive and integrative processes. Despite this emerging relevance, the CBL has received comparatively less attention in aging research, which has focused mainly on other central nervous system (CNS) regions such as the neocortex and hippocampus. This review synthesizes the current evidence on glial cell aging across the CNS, emphasizing how cerebellar circuits follow distinct trajectories in terms of cellular remodeling, transcriptional reprogramming, and structural vulnerability. Recent findings highlight that cerebellar astrocytes and microglia exhibit specific signatures related to aging compared to their cortical counterpart, including moderate reactivity, selective immune response, and spatial reorganization. Cerebellar white matter (WM) undergoes structural alteration, suggesting that oligodendroglial cells may undergo region-specific alterations, particularly within WM tracts, although these aspects remain underexplored. Despite the presence of glial remodeling, the CBL maintains a notable degree of structural and functional integrity during aging. This resilience may be the result of the CBL’s ability to maintain synaptic adaptability and homeostatic balance, supported by its highly organized and compartmentalized architecture. A better understanding of the dynamics of cerebellar glial cells in aging may provide new insight into the mechanisms of brain maintenance and identify potential biomarkers for healthy brain aging. Full article

The habenula (Hb) of the epithalamus is formed of the medial (MHb) and lateral (LHb) parts. The improper functioning of the Hb may lead to depression and anxiety. The glutamate excitotoxicity is accompanied by astroglia reactivity and leads to the damage of nervous system structures. The aim of the study was to assess the influence of monosodium glutamate (MSG) administrated subcutaneously to rats in doses of 2 g/kg b.w. (I) and 4 g/kg b.w. (II), on astroglia in the MHb and LHb. Based on immunohistochemical reactions, the morphology, number of astrocytes immunoreactive for glial fibrillary acidic protein (GFAP-IR) and S100β protein (S100β-IR), and their surface area, perimeter, number and length of processes, and cytoplasmic-nuclear immunostaining intensity for the studied proteins were assessed. In the MHb of animals receiving MSG, especially at a high dose, hypertrophy and an increase in the number of GFAP-IR and S100β-IR cells were demonstrated. In the LHb, only hypertrophy of processes in S100β-positive glia was observed. The immunostaining intensity increased in GFAP-IR glia and decreased in S100β-IR cells only in animals from group I. The results revealed that astroglia respond to MSG depending on its dose and the Hb part. This different behavior of glia may indicate their different sensitivity and resistance to damaging factors. Full article

High-altitude cognitive impairment (HACI) results from acute or chronic exposure to hypoxic conditions. Brain lipid homeostasis is crucial for cognitive function, and lipid droplet (LD) accumulation in glia cells is linked to cognitive decline in aging and stroke. However, whether high-altitude exposure affects brain lipid homeostasis is unclear. Microglia, key regulators of brain homeostasis and inflammation, play a significant role in pathological cognitive impairment and are implicated in LD formation. This study investigates whether lipid dysregulation contributes to HACI and explores microglia-driven mechanisms and potential interventions. Mice were exposed to a simulated 7000 m altitude for 48 h, followed by a week of recovery. Cognitive function and LD accumulation in brain cells were assessed. Microglia were depleted using PLX5622, and mice were exposed to hypoxia or lipopolysaccharide (LPS) to validate microglia’s role in driving astrocytic LD accumulation and cognitive decline. Minocycline was used to inhibit inflammation. In vitro, co-culture systems of microglia and astrocytes were employed to confirm microglia-derived pro-inflammatory factors’ role in astrocytic LD accumulation. Hypobaric hypoxia exposure induced persistent cognitive impairment and LD accumulation in hippocampal astrocytes and microglia. Microglia depletion alleviated cognitive deficits and reduced astrocytic LD accumulation. Hypoxia or LPS did not directly cause LD accumulation in astrocytes but activated microglia to release IL-1β, inducing astrocytic LD accumulation. Microglia depletion also mitigated LPS-induced cognitive impairment and astrocytic LD accumulation. Minocycline reduced hypoxia-induced LD accumulation in co-cultured astrocytes and improved cognitive function. Hypoxia triggers pro-inflammatory microglial activation, leading to LD accumulation and the release of IL-1β, which drives astrocytic LD accumulation and neuroinflammation, exacerbating HACI. Minocycline effectively restores brain lipid homeostasis and mitigates cognitive impairment. This study provides novel insights into HACI mechanisms and suggests potential therapeutic strategies. Full article

The circadian clock is a self-sustaining oscillator with a period of approximately 24 h, enabling organisms to anticipate daily recurring events, such as sunrise and sunset. Since the circadian period is not exactly 24 h and the environmental day length varies throughout the year, the clock must be periodically reset to align an organism’s physiology with the natural light/dark cycle. This synchronization, known as entrainment, is primarily regulated by nocturnal light, which can be replicated in laboratory settings using a 15 min light pulse (LP) and by assessing locomotor activity. An LP during the early part of the dark phase delays the onset of locomotor activity, resulting in a phase delay, whereas an LP in the late dark phase advances activity onset, causing a phase advance. The clock gene Period 2 (Per2) plays a key role in this process. To investigate its contributions, we examined the effects of Per2 deletion in neurons versus astrocytes using glia-specific GPer2 (Per2/GfapCre) knockout (KO) and neuronal-specific NPer2KO (Per2/NesCre) mice. All groups were subjected to Aschoff type II protocol, where an LP was applied at ZT14 or ZT22 and the animals were released into constant darkness. As control, no LP was applied. Phase shift, period, amplitude, total activity count, and rhythm instability were assessed. Our findings revealed that mice lacking Per2 in neurons (NPer2) exhibited smaller phase delays and larger phase advances compared to control animals. In contrast, mice with Per2 deletion specifically in glial cells including astrocytes (GPer2) displayed normal clock resetting. Interestingly, the absence of Per2 in either of the cell types resulted in a shorter circadian period compared to control animals. These results suggest that astrocytic Per2 is important for maintaining the circadian period but is not required for phase adaptation to light stimuli. Full article

Background: The retina, a light-sensitive tissue of the central nervous system that is located at the posterior part of the eye, is particularly vulnerable to alterations in oxygen levels. In various retinal diseases, such as central retinal vein occlusion, glaucoma, and diabetic retinopathy, hypoxia (a condition of low oxygen levels) is commonly observed. Müller glia, the principal glial cells in the retina, play a crucial role in supporting the metabolic needs of retinal neurons. They are also responsible for sensing oxygen levels and, in response to hypoxia, express Hypoxia-Inducible Factor 1 (HIF-1), a transcription factor that activates signaling pathways related to hypoxia. Methods: In this study, primary rat Müller glial cells were cultured and exposed to a 1% oxygen for 72 h. Following this, immunohistochemical assays were conducted to assess the effects of hypoxia on various parameters, including HIF-1α expression, cell survival, Müller glia-specific markers (CRALBP and GS), gliosis (GFAP expression), apoptosis (caspase-3 expression), cell proliferation (Ki-67 expression), and metabolic stress (indicated by the number of mitochondria per cell). Results: Under hypoxic conditions, a decrease in Müller glial survival and proliferation was observed. Conversely, there was an increase in HIF-1α expression, GFAP expression, caspase-3-positive cells, and the number of mitochondria per cell. However, no significant changes were noted in the expression of the Müller glial markers GS and CRALBP. Conclusions: In conclusion, hypoxia resulted in reduced proliferation and survival of Müller glial cells, primarily due to increased apoptosis and heightened metabolic stress. Full article

Background/Objective: The Rs1 exon-1-del rat (Rs1KO) XLRS model shows normal retinal development until postnatal day 12 (P12) when small cystic spaces start to form in the inner nuclear layer. These enlarge rapidly, peak at P15, and then collapse by P19. These events overlap with eye opening at P12–P15. We investigated whether new light-driven retinal activity could contribute to the appearance and progression of schisis cavities in this rat model of XLRS disease. Methods: For dark rearing (D/D), mating pairs of Rs1KO strain were raised in total darkness in a special vivarium at UC Davis. When pups were born, they were maintained in total darkness, and eyes were collected at P12, P15, and P30 (n = 3/group) for each of the D/D and cyclic light-reared 12 h light–12 h dark (L/D) Rs1KO and wild-type (WT) littermates. Eyes were fixed, paraffin-embedded, and sectioned. Tissue morphology was examined by H&E and marker expression of retinoschisin1 (Rs1), rhodopsin (Rho), and postsynaptic protein 95 (Psd95) by fluorescent immunohistochemistry. H&E-stained images were analyzed with ImageJ version 1.54h to quantify cavity size using the “Analyze Particles” function. Results: Small intra-retinal schisis cavities begin to form by P12 in the inner retina of both D/D and L/D animals. Cavity formation was equivalent or more pronounced in D/D animals than in L/D animals. We compared Iba1 (activation marker of immune cells) distribution and found that by P12, when schisis appeared, Iba1⁺ cells had accumulated in regions of schisis. Iba1⁺ cells were more abundant in Rs1KO animals than WT animals and appeared slightly more prevalent in D/D- than L/D-reared Rs1KO animals. We compared photoreceptor development using Rho, Rs1, and Psd95 expression, and these were similar; however, the outer segments (OSs) of D/D animals with Rho labeling at P12 were longer than L/D animals. Conclusions: The results showed that cavities formed at the same time in D/D and L/D XLRS rat pups, indicating that the timing of schisis formation is not light stimulus-driven but rather appears to be a result of developmental events. Cavity size tended to be larger under dark-rearing conditions in D/D animals, which could be due to the decreased rate of phagocytosis by the RPE in the dark, allowing for continued growth of the OSs without the usual shedding of the distal tip, a key mechanism behind dark adaptation in the retina. These results highlight the complexity of XLRS pathology; however, we found no evidence that light-driven metabolic activity accounted for schisis cavity formation. Full article

Glial cells, once considered mere support for neurons, have emerged as key players in brain function across vertebrates. The historical study of glia dates to the 19th century with the identification of ependymal cells and astrocytes, followed by the discovery of oligodendrocytes and microglia. While neurocentric perspectives overlooked glial functions, recent research highlights their essential roles in neurodevelopment, synapse regulation, brain homeostasis, and neuroimmune responses. In teleost fish, a group comprising over 32,000 species, glial cells exhibit unique properties compared to their mammalian counterparts. Thus, the aim of this review is synthesizing the current literature on fish glial cells, emphasizing their evolutionary significance, diversity, and potential as models for understanding vertebrate neurobiology. Microglia originate from both yolk sac cells and hematopoietic stem cells, forming distinct populations with specialized functions in the adult brain. Neural stem cells, including radial glial cells (RGCs) and neuroepithelial cells, remain active throughout life, supporting continuous neuro- and gliogenesis, a phenomenon far more extensive than in mammals. Ependymocytes line brain ventricles and show structural variability, with some resembling quiescent progenitor cells. Astrocytes are largely absent in most fish species. However, zebrafish exhibit astrocyte-like glial cells which show some structural and functional features in common with mammalian astrocytes. Oligodendrocytes share conserved mechanisms with mammals in myelination and axon insulation. Full article

Clusterin (CLU) is a heterodimeric, ATP-independent molecular chaperone that exhibits high expression in the brain. While CLU primarily functions in the extracellular environment, its chaperone activity in the intracellular compartment under different stress conditions, as well as its involvement in various signaling networks, has been demonstrated. CLU has been extensively associated with Alzheimer’s Disease; however, increasing evidence links this chaperone to Parkinson’s Disease (PD) as well. Thus, in this review we will discuss evidence concerning the involvement of CLU in the pathogenesis of PD with a particular focus on molecular mechanisms leading to the formation and the spreading of alpha-Synuclein (α-Syn) aggregates. Specifically, the role of CLU will be discussed in neurons and in glial cells, taking into account that the neuron–glia cross-talk is an essential and dynamic interplay that is compromised in neurodegenerative disorders. Moreover, the possible role of CLU as a biomarker in different biological fluids, such as cerebrospinal fluid, plasma, and serum, and its therapeutic potential will be addressed. In this regard, the past years have seen huge efforts to discover molecules able to mitigate α-Syn burden and its related toxicity. Overall, this overview highlights CLU as an intriguing target that can affect biochemical events underlying PD pathology. Full article

Retinal detachment (RD) is a serious clinical condition that significantly impacts patients’ quality of life. Its management involves considering several clinical factors that may affect the therapeutic approach. Inflammatory complications can affect visual recovery, long-term outcomes, and prognosis. Understanding the underlying inflammatory mechanisms is key to improving personalized medicine and optimizing therapeutic approaches to management. This review comprehensively searched scientific databases (Medline, Web of Science, and Scopus), considering clinical and experimental studies published between 1999 and 2025. Specific MeSH terms and predefined inclusion and exclusion criteria were used to select the most relevant papers. A total of 140 studies were analyzed. The findings were analyzed qualitatively and illustrated with images from clinical practice. Several studies have demonstrated the critical role of cytokines in retinal inflammation, highlighting their importance in regulating the immune response following RD. In addition, oxidative stress, apoptotic mechanisms, and glia activation, particularly Müller cells and microglia, have been identified as crucial elements in the progression of retinal damage. In this sense, inflammation poses significant clinical challenges that require more effective therapeutic strategies. In conclusion, this review differs from previous literature by emphasizing the translational implications of inflammatory mechanisms in RD and by comparing experimental and clinical data. The management of RD should consider not only surgical aspects, but also modulation of the inflammatory response to improve visual outcomes and prevent long-term complications. Full article

Chronic migraine (CM) is a debilitating neurological disorder, yet the glial-specific mechanisms underlying its pathophysiology in the trigeminal nucleus caudalis (TNC)—a critical hub for craniofacial pain processing—remain poorly understood. Here, we employed single-nucleus RNA sequencing (snRNA-seq) to resolve cell-type-specific transcriptional landscapes in a nitroglycerin (NTG)-induced CM rat model, with a particular focus on microglia and astrocytes. We identified 19 transcriptional clusters representing nine major cell types, among which reactive microglia (NTG-Mic) and astrocytes (NTG-Asts) were markedly expanded. The NTG-Mic displayed a glycolysis-dominant, complement-enriched state, whereas the NTG-Asts exhibited concurrent activation of amino acid transport and cytokine signaling pathways. Pseudotime trajectory analysis revealed bifurcated glial activation paths, with NTG driving both cell types toward terminal reactive states. Intercellular communication inference uncovered suppressed homeostatic interactions (e.g., CSF1-CSF1R) alongside enhanced proinflammatory signaling (e.g., FGF1-FGFR2, PTN-SDC4), particularly affecting neuron–glia and glia–glia crosstalk. Together, these findings define a high-resolution atlas of glial reprogramming in CM, implicating state-specific metabolic–immune transitions and dysregulated glial communication as potential targets for therapeutic intervention. Full article

Cholinergic projections from the basal forebrain to the cortex and hippocampus play a critical role in cognitive functions, many of which rely on signaling through the alpha7 nicotinic acetylcholine receptor (α7nAChR). The Alzheimer’s disease (AD) brain is characterized by the profound impairment of the basal forebrain cholinergic system, including alterations in the levels of α7nAChR in various brain areas. In addition, α7nAChR binds with high affinity to beta amyloid (Aβ), suggesting α7nAChR might mediate some of Aβ’s effects in the brain. Under normal physiological conditions, the interaction between Aβ and α7nAChR appears to be beneficial, supporting normal neurotransmission, synaptic plasticity, and memory functions. However, when levels of Aβ are pathologically elevated, their interaction leads to deleterious effects, implicating α7nAChR in the pathophysiology of AD. In addition to expression in neurons, α7nAChR is expressed in astrocytes and microglia, where it serves as a key component of a cholinergic pathway that regulates neuroinflammation. This review article will cover the role of α7nAChR in neurons, astrocytes and microglia under normal conditions, summarize changes in the expression or function of α7nAChR in neurons and glia in the AD brain, and discuss cell-type specific contributions of α7nAChR to AD pathology with an emphasis on interactions of α7nAChR with Aβ. Full article

Dietary marine lipids enriched in ω-3 polyunsaturated fatty acids (PUFAs) are spotlighted for favorable effects in neurodegenerative conditions and tumor cell proliferation. Commercial marine oils, with high EPA and DHA content, consist of non-polar lipids constituted by triacylglycerols or polar oils composed of phospholipids. Both classes have shown different activities to significantly inhibit proliferation and migration, and induce apoptosis in cancer cells. This work was aimed at testing marine oils’ associated effects on neuroblastoma (NB) and glioblastoma (GB). Commercial non-polar and polar marine oils were studied in 3D spheroid models developed with human neuroblastoma, GB, and non-nervous embryonic kidney cell lines. This study also included results provided by a new sustainable polar marine oils source: fishery side-streams. Cell viability and mitochondrial activity assessments demonstrated that both marine oils dramatically reduced NB cells’ metabolism, proliferation, and viability. Effects on GB and epithelial cells were different, including a metabolic increase. Marine oils also induce cell differentiation and selectively modulate the activity of neurons and glia, depending on the oils’ chemical form. Sustainable polar oil showed bioactive characteristics similar to commercial krill oil. We propose that marine oils rich in triacylglycerols and phospholipids with high EPA and DHA levels may be a useful tool in NB antiproliferative therapies. Full article

Glial cells exhibit multifaceted functions and represent essential contributors to various physiological processes in the brain, rather than just being silent supportive cells to neurons. Different glial populations of the central nervous system within involved brain regions play various functions, express different proteins, and result in fluctuating effects when altered. Glial cell pathologies were detected in most mental disorders including suicidal behavior. Suicidal behavior represents a health problem of high importance worldwide, where protective measures are required to be taken at many levels. Studies on patients with mental disorders that represent risk factors for suicidal behavior revealed multiple changes in the glia at diverse levels, including variations regarding the expressed glial markers. This review summarizes the role of glia in some psychiatric disorders and highlights the crosslink between changes at the level of glial cells and development of suicidal behavior in patients with an underlying psychiatric condition; in addition, the interplay and interconnection between suicidal behavior and other mental diseases will shed light on the routes of personalized therapy involving the development of glia-related drugs. Full article

Epigenetic rearrangements can create a favorable environment for the intrinsic plasticity of brain cells, leading to cellular reprogramming into virtually any cell type through the induction of cell-specific transcriptional programs. In this study, we assessed how chromatin remodeling induced by broad-spectrum HDAC inhibitors affects cellular differentiation trajectories in rat primary neuron–glia cultures using a combination of transcriptomics, qPCR, and cytochemistry. We described the epigenetic regulation of transcriptional programs controlled by master transcription factors and neurotrophins in the context of neuronal and glial differentiation and evaluated the expression of representative cell-specific markers. The results obtained suggest that HDAC inhibitors reduce the proliferative potential of cultured cells and induce transcriptomic changes associated with cell differentiation and specialization. Particularly, we revealed a significant upregulation of genes typically expressed in neuromodulatory neurons and the downregulation of genes expressed in glia and inhibitory neurons. Transcriptional changes were accompanied by continuous elevation of histone serotonylation levels in both neurons and glia. Emerging shortly after HDAC inhibition, a complex chromatin remodeling, which includes histone serotonylation, persists over many hours in distinct brain cells. We assume that this sustained epigenetic mechanism likely helps to maintain transcriptional changes associated with cell fate commitment, possibly priming cells for long-term fate conversion. Full article

Oligodendrocytes form myelin in the central nervous system, and their dysfunction can cause severe neurological symptoms, as large-scale analyses have highlighted numerous gene expression alterations in pathological conditions. Although in vivo functional gene analyses are preferable, they have several limitations, especially in large-scale studies. Therefore, standardized in vitro systems are needed to facilitate efficient and reliable functional analyses of genes identified in such studies. Here, we describe a practical and efficient method for oligodendrocyte precursor cell (OPC) isolation from mouse brains on postnatal day 6–8 and a gene delivery method for the isolated OPCs. By modifying the magnetic-activated cell sorting (MACS) procedure with reduced processing volumes, we simplified OPC isolation, allowing simultaneous handling of multiple samples and improving workflow efficiency. We also optimized electroporation parameters to achieve robust transfection efficiency with minimal cell death. Transfected OPCs are suitable for both monoculture-based differentiation assays and co-culture with dorsal root ganglion (DRG) explants, in which they reliably differentiate into mature oligodendrocytes and myelinate along the axons. This system enables stable and reproducible in vitro analysis of oligodendrocyte function, supports investigations into both intrinsic differentiation and neuron–glia interactions, and provides a powerful platform for oligodendrocyte research with efficient and timely gene manipulation. Full article