NG2 glia display wide proliferation and differentiation potential under physiological and pathological conditions. Here, we examined these two features following different types of brain disorders such as focal cerebral ischemia (FCI), cortical stab wound (SW), and demyelination (DEMY) in 3-month-old mice, in which NG2 glia are labeled by tdTomato under the Cspg4 promoter. To compare NG2 glia expression profiles following different CNS injuries, we employed single-cell RT-qPCR and self-organizing Kohonen map analysis of tdTomato-positive cells isolated from the uninjured cortex/corpus callosum and those after specific injury. Such approach enabled us to distinguish two main cell populations (NG2 glia, oligodendrocytes), each of them comprising four distinct subpopulations. The gene expression profiling revealed that a subpopulation of NG2 glia expressing GFAP, a marker of reactive astrocytes, is only present transiently after FCI. However, following less severe injuries, namely the SW and DEMY, subpopulations mirroring different stages of oligodendrocyte maturation markedly prevail. Such injury-dependent incidence of distinct subpopulations was also confirmed by immunohistochemistry. To characterize this unique subpopulation of transient astrocyte-like NG2 glia, we used single-cell RNA-sequencing analysis and to disclose their basic membrane properties, the patch-clamp technique was employed. Overall, we have proved that astrocyte-like NG2 glia are a specific subpopulation of NG2 glia emerging transiently only following FCI. These cells, located in the postischemic glial scar, are active in the cell cycle and display a current pattern similar to that identified in cortical astrocytes. Astrocyte-like NG2 glia may represent important players in glial scar formation and repair processes, following ischemia.

• Klíčová slova
• NG2 glia, astrocytes, demyelination, ischemia, oligodendrocytes, stab wound,
• MeSH
• astrocyty * metabolismus   MeSH
• glióza patologie   MeSH
• ischemie mozku * metabolismus   MeSH
• myši MeSH
• neuroglie metabolismus   MeSH
• oligodendroglie patologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Glial cells expressing neuron-glial antigen 2 (NG2), also known as oligodendrocyte progenitor cells (OPCs), play a critical role in maintaining brain health. However, their ability to differentiate after ischemic injury is poorly understood. The aim of this study was to investigate the properties and functions of NG2 glia in the ischemic brain. Using transgenic mice, we selectively labeled NG2-expressing cells and their progeny in both healthy brain and after focal cerebral ischemia (FCI). Using single-cell RNA sequencing, we classified the labeled glial cells into five distinct subpopulations based on their gene expression patterns. Additionally, we examined the membrane properties of these cells using the patch-clamp technique. Of the identified subpopulations, three were identified as OPCs, whereas the fourth subpopulation had characteristics indicative of cells likely to develop into oligodendrocytes. The fifth subpopulation of NG2 glia showed astrocytic markers and had similarities to neural progenitor cells. Interestingly, this subpopulation was present in both healthy and post-ischemic tissue; however, its gene expression profile changed after ischemia, with increased numbers of genes related to neurogenesis. Immunohistochemical analysis confirmed the temporal expression of neurogenic genes and showed an increased presence of NG2 cells positive for Purkinje cell protein-4 at the periphery of the ischemic lesion 12 days after FCI, as well as NeuN-positive NG2 cells 28 and 60 days after injury. These results suggest the potential development of neuron-like cells arising from NG2 glia in the ischemic tissue. Our study provides insights into the plasticity of NG2 glia and their capacity for neurogenesis after stroke.

• Klíčová slova
• NG2 glia heterogeneity, chondroitin sulfate proteoglycan 4, focal cerebral ischemia, neurogenesis, oligodendrocyte precursor cell, single-cell RNA sequencing,
• MeSH
• antigeny metabolismus   MeSH
• astrocyty metabolismus   MeSH
• ischemie mozku * metabolismus   MeSH
• mozek metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• nervové kmenové buňky * metabolismus   MeSH
• neuroglie metabolismus   MeSH
• oligodendroglie metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny MeSH

Extrasynaptic communication between neurons or neurons and glia is mediated by the diffusion of neuroactive substances through the extracellular space (ECS). Structural changes and amino acid release occurring under physiological and pathological conditions result in cellular (particularly glial) swelling, leading to dynamic changes in the ECS volume and geometry that in turn affect ECS diffusion. Significant changes in ECS volume and in diffusion barriers occur during development and aging. They are often the result of cell death, astrogliosis, the rearrangement of astrocytic processes and changes in extracellular matrix molecules. Plastic changes in ECS volume, geometry and anisotropy significantly affect the spatial relation of glial processes towards synapses, glutamate or GABA 'spillover', synaptic cross-talk and neuron-glia communication/interaction. In addition, changes occurring during pathological states can be important for diagnosis, drug delivery and treatment.

• MeSH
• difuze MeSH
• extracelulární prostor fyziologie   MeSH
• lidé MeSH
• mezibuněčná komunikace fyziologie   MeSH
• mozek patologie   fyziologie   MeSH
• nervový přenos fyziologie   MeSH
• neuroglie patologie   fyziologie   MeSH
• stárnutí patologie   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Stimulation-evoked transient changes in extracellular potassium ([K+]e) and pH (pHe) were studied in the neonatal rat spinal cords isolated from 3-13-day-old pups. In unstimulated pups the [K+]e baseline was elevated and pHe was more acid than that in Ringer's solution (3.5 mM K+, pH 7.3-7.35). The [K+]e and pHe in 3-6-day-old pups was 3.91 +/- 0.12 mM and pHe 7.19 +/- 0.01, respectively, while in 10-13-day-old pups it was 4.35 +/- 0.15 mM and 7.11 +/- 0.01, respectively. The [K+]e changes evoked in the dorsal horn by a single electrical stimulus were as large as 1.5-2.5 mM. Such changes in [K+]e are evoked in the adult rat spinal cord with stimulation at a frequency of 10-30 Hz. The maximal changes of 2.1-6.5 mM were found at a stimulation frequency of 10 Hz in 3-6-day-old animals. In older animals the [K+]e changes progressively decreased. The poststimulation K(+)-undershoot was found after a single stimulus as well as after repetitive stimulation. In 3-8-day-old pups, the stimulation evoked an alkaline shift, which was followed by a smaller poststimulation acid shift when the stimulation was discontinued. In pups 3-4-days-old the stimulation evoked the greatest alkaline shifts, i.e., by as much as 0.05 pH units after a single pulse and by about 0.1 pH units during stimulation at a frequency of 10 Hz. In 5-8-day-old pups, the alkaline shift became smaller and the poststimulation acid shift increased.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• acetazolamid farmakologie   MeSH
• acidobazická rovnováha účinky léků   fyziologie   MeSH
• chlorid hořečnatý farmakologie   MeSH
• draslík metabolismus   MeSH
• elektrická stimulace MeSH
• extracelulární prostor metabolismus   MeSH
• homeostáza MeSH
• inbrední kmeny potkanů MeSH
• intracelulární tekutina metabolismus   MeSH
• karboanhydrasy fyziologie   MeSH
• koncentrace vodíkových iontů MeSH
• krysa rodu Rattus MeSH
• mícha cytologie   metabolismus   MeSH
• neuroglie fyziologie   MeSH
• novorozená zvířata MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetazolamid MeSH
• chlorid hořečnatý MeSH
• draslík MeSH
• karboanhydrasy MeSH

• MeSH
• elektronová mikroskopie MeSH
• fagocytóza MeSH
• krysa rodu Rattus MeSH
• mozek ultrastruktura   MeSH
• neuroglie fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The role of glia in amyotrophic lateral sclerosis (ALS) is undeniable. Their disease-related activity has been extensively studied in the spinal cord, but only partly in the brain. We present herein a comprehensive study of glia in the cortex of SOD1(G93A) mice-a widely used model of ALS. Using single-cell RNA sequencing (scRNA-seq) and immunohistochemistry, we inspected astrocytes, microglia, and oligodendrocytes, in four stages of the disease, respecting the factor of sex. We report minimal changes of glia throughout the disease progression and regardless of sex. Pseudobulk and single-cell analyses revealed subtle disease-related transcriptional alterations at the end-stage in microglia and oligodendrocytes, which were supported by immunohistochemistry. Therefore, our data support the hypothesis that the SOD1(G93A) mouse cortex does not recapitulate the disease in patients, and we recommend the use of a different model for future studies of the cortical ALS pathology.

• MeSH
• amyotrofická laterální skleróza * genetika   patologie   MeSH
• mícha patologie   MeSH
• modely nemocí na zvířatech MeSH
• motorické neurony patologie   MeSH
• myši transgenní MeSH
• myši MeSH
• neuroglie * patologie   MeSH
• superoxiddismutasa 1 * genetika   MeSH
• superoxiddismutasa genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• superoxiddismutasa 1 * MeSH
• superoxiddismutasa MeSH

Changes in brain extracellular space (ECS) volume, composition, and geometry are a consequence of neuronal activity, of glial K+, pH, and amino acid homeostasis, and of changes in glial cell morphology, proliferation, and function. They occur as a result of repetitive neuronal activity, seizures, anoxia, injury, inflammation, and many other pathological states in the CNS, and may significantly affect signal transmission in the CNS. Activity-related or CNS damage-related cellular swelling is compensated for by ECS volume shrinkage and, as a consequence, by a decrease in the apparent diffusion coefficients (ADCs) of neuroactive substances diffusing in the ECS. Changes in cellular morphology, such as occur during aging, could also result in changes of ECS volume and geometry. We provide evidence for limited diffusion in rat cortex, corpus callosum, and hippocampus in the aging brain that correlates with changes in glial volume and the extracellular matrix. In all structures, the mean ECS volume fraction alpha (alpha = ECS volume/total tissue volume) and nonspecific uptake k' are significantly lower in aged rats (26-32 months old) than in young adult brain. Compared to young adult brain, in the aged brain we found an increase in GFAP staining and hypertrophied astrocytes with thicker processes which, in the hippocampus, lost their radial organization. The tortuosity (lambda = square root of D/ADC) was lower in the cortex and CA3 region. Immunohistochemical staining for fibronectin and chondroitin sulfate proteoglycans revealed a substantial decrease that could account for a decrease in diffusion barriers. Diffusion parameters alpha, lambda, and k' in the aging brain after cardiac arrest changed substantially faster than in the young adult brain, although the final values were not significantly different. This suggests that the smaller extracellular space during aging results in a greater susceptibility of the aging brain to anoxia/ischemia, apparently due to a faster extracellular acidosis and accumulation of K+ and toxic substances, for example, glutamate. We conclude that during aging the movement of substances is more hindered in the narrower clefts. This is partly compensated for by a decrease in the diffusion barriers that may be formed by macromolecules of the extracellular matrix. Diffusion parameters can affect the efficacy of synaptic as well as extrasynaptic transmission by a greater accumulation of substances, because they diffuse away from a source more slowly, or induce damage to nerve cells if these substances reach toxic concentrations. Diffusion parameters are also of importance in the "crosstalk" between synapses, which has been hypothesized to be of importance during LTP and LTD. We can, therefore, assume that the observed changes in ECS diffusion parameters during aging can contribute to functional deficits and memory loss.

• MeSH
• difuze MeSH
• extracelulární prostor metabolismus   MeSH
• ischemie mozku metabolismus   patologie   MeSH
• krysa rodu Rattus MeSH
• mezibuněčná komunikace fyziologie   MeSH
• mozek cytologie   metabolismus   patologie   fyziologie   MeSH
• neuroglie fyziologie   MeSH
• neurony fyziologie   MeSH
• potkani Wistar MeSH
• stárnutí fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The incorporation of 14C-leucine into the post-mitochondrial supernatant and neuron, glia and myelin-enriched fractions isolated from the rabbit spinal cord was studied after ischaemia and subsequent recirculation. In the cell-free system, incorporation decreased to 55% of the control value after 40 min ischaemia, but proteosynthesis returned to the pre-ischaemic value after 3 h recirculation and remained at this level during further recirculation. The incorporation of amino acids into proteins of neurons and neuroglia differed from the cell-free system and from each other. In the enriched neuronal fraction, protein synthesis fall after ischaemia and also during the first hours of recirculation, but during further recirculation it rose to 60% above the control value. In the enriched glial fraction, specific radioactivity of proteins rose abruptly immediately after ischaemia and by the fourth day there was sixfold increase as compared with control values. The results indicate that the ischaemia-induced decrease in protein synthesis is only transient and that a significant increase occurs in the surviving cell populations, especially the neuroglia. The functional changes caused by spinal cord ischaemia are irreversible, however.

• MeSH
• bezbuněčný systém MeSH
• ischemie metabolismus   MeSH
• králíci MeSH
• mícha krevní zásobení   metabolismus   MeSH
• neuroglie metabolismus   MeSH
• neurony metabolismus   MeSH
• proteiny nervové tkáně biosyntéza   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteiny nervové tkáně MeSH

Activity-related changes in extracellular K+ concentration ([K+]e), pH (pHe) and extracellular volume were studied by means of ion-selective microelectrodes in the adult rat spinal cord in vivo and in neonatal rat spinal cords isolated from pups 3-14 days of age (P3-P14). Concomitantly with the ionic changes, the extracellular space (ECS) volume fraction (alpha), ECS tortuosity (lambda) and non-specific uptake (kappa'), three parameters affecting the diffusion of substances in nervous tissue, were studied in the rat spinal cord gray matter. In adult rats, repetitive electrical nerve stimulation (10-100 Hz) elicited increases in [K+]e of about 2.0-3.5 mM, followed by a post-stimulation K(+)-undershoot and triphasic alkaline-acid-alkaline changes in pHe with a dominating acid shift. The ECS volume in the adult rat occupies about 20% of the tissue, alpha = 0.20 +/- 0.003, lambda = 1.62 +/- 0.02 and kappa' = 4.6 +/- 0.4 x 10(-3) s-1 (n = 39). In contrast, in pups at P3-P6, the [K+]e increased by as much as 6.5 mM at a stimulation frequency of 10 Hz, i.e. K+ ceiling level was elevated, and there was a dominating alkaline shift. An increase in [K+]e as large as 1.3-2.5 mM accompanied by an alkaline shift was evoked by a single electrical stimulus. The K+ ceiling level and alkaline shifts decreased with age, while an acid shift, which was preceded by a small initial alkaline shift, appeared in the second postnatal week. In pups at P1-P2, the spinal cord was X-irradiated to block gliogenesis. The typical decrease in [K+]e ceiling level and the development of the acid shift in pHe at P10-P14 were blocked by X-irradiation. Concomitantly, continuous development of glial fibrillary acidic protein positive reaction was disrupted and densely stained astrocytes in gray matter at P10-P14 revealed astrogliosis. The alkaline, but not the acid, shift was blocked by Mg2+ and picrotoxin (10(-6) M). Acetazolamide enhanced the alkaline but blocked the acid shift. Furthermore, the acid shift was blocked, and the alkaline shift enhanced, by Ba2+, amiloride and SITS. Application of glutamate or gamma-aminobutyric acid evoked an alkaline shift in the pHe baseline at P3-P14 as well as after X-irradiation. The results suggest that the activity-related acid shifts in pHe are related to membrane transport processes in mature glia, while the alkaline shifts have a postsynaptic origin and are due to activation of ligand-gated ion channels.(ABSTRACT TRUNCATED AT 400 WORDS)

• MeSH
• acetazolamid farmakologie   MeSH
• amilorid farmakologie   MeSH
• baryum farmakologie   MeSH
• chlorid hořečnatý farmakologie   MeSH
• draslík metabolismus   MeSH
• elektrická stimulace MeSH
• extracelulární prostor fyziologie   MeSH
• GABA farmakologie   MeSH
• glutamáty farmakologie   MeSH
• homeostáza MeSH
• koncentrace vodíkových iontů MeSH
• krysa rodu Rattus MeSH
• kvartérní amoniové sloučeniny farmakologie   MeSH
• kyselina 4-acetamido-4'-isothiokyanatostilben-2,2'-disulfonová farmakologie   MeSH
• kyselina glutamová MeSH
• mezibuněčná komunikace MeSH
• mícha růst a vývoj   fyziologie   účinky záření   MeSH
• neuroglie účinky léků   fyziologie   MeSH
• neurony účinky léků   fyziologie   MeSH
• potkani Wistar MeSH
• stárnutí fyziologie   MeSH
• techniky in vitro MeSH
• vysoká teplota MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetazolamid MeSH
• amilorid MeSH
• baryum MeSH
• chlorid hořečnatý MeSH
• draslík MeSH
• GABA MeSH
• glutamáty MeSH
• kvartérní amoniové sloučeniny MeSH
• kyselina 4-acetamido-4'-isothiokyanatostilben-2,2'-disulfonová MeSH
• kyselina glutamová MeSH
• tetramethylammonium MeSH Prohlížeč

Depression is a complex disorder related to chronic inflammatory processes, chronic stress changes and a hippocampal response. There is a increasing knowledge about the role of glial cells in nutrient supply to neurons, maintenance of synaptic contacts and tissue homeostasis within the CNS. Glial cells, viewed in the past as passive elements with a limited influence on neuronal function, are becoming recognized as active partners of neurons and are starting to be discussed as a possible therapeutic target. Their role in the pathogenesis of depressive disorders is also being reconsidered. Attention is devoted to studies of the different types of antidepressants and their effects on transmembrane signaling, including levels of alpha subunits of G proteins in C6 glioma cells in vitro as a model of postsynaptic changes in vivo. These models indicate similarities in antidepressant effects on G proteins of brain cells and effector cells of natural immunity, natural killers and granulocytes. Thus, an antidepressant response can exhibit certain common characteristics in functionally different systems which also participate in disease pathogenesis. There are, however, differences in the astrocyte G-protein responses to antidepressant treatment, indicating that antidepressants differ in their effect on glial signalization. Today mainstream approach to neurobiological basis of depressive disorders and other mood illnesses is linked to abnormalities in transmembrane signal transduction via G-protein coupled receptors. Intracellular signalization cascade modulation results in the activation of transcription factors with subsequent increased production of a wide array of products including growth factors and to changes in cellular activity and reactivity.

• MeSH
• adaptace psychologická účinky léků   MeSH
• antidepresiva farmakologie   MeSH
• depresivní poruchy farmakoterapie   etiologie   patofyziologie   MeSH
• lidé MeSH
• nervový přenos účinky léků   MeSH
• neuroglie účinky léků   MeSH
• psychický stres komplikace   patofyziologie   MeSH
• signální transdukce účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antidepresiva MeSH