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1.
J Neurosci ; 43(18): 3245-3258, 2023 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-36948583

RESUMEN

Mirror-image pain arises from pathologic alterations in the nociceptive processing network that controls functional lateralization of the primary afferent input. Although a number of clinical syndromes related to dysfunction of the lumbar afferent system are associated with the mirror-image pain, its morphophysiological substrate and mechanism of induction remain poorly understood. Therefore, we used ex vivo spinal cord preparation of young rats of both sexes to study organization and processing of the contralateral afferent input to the neurons in the major spinal nociceptive projection area Lamina I. We show that decussating primary afferent branches reach contralateral Lamina I, where 27% of neurons, including projection neurons, receive monosynaptic and/or polysynaptic excitatory drive from the contralateral Aδ-fibers and C-fibers. All these neurons also received ipsilateral input, implying their involvement in the bilateral information processing. Our data further show that the contralateral Aδ-fiber and C-fiber input is under diverse forms of inhibitory control. Attenuation of the afferent-driven presynaptic inhibition and/or disinhibition of the dorsal horn network increased the contralateral excitatory drive to Lamina I neurons and its ability to evoke action potentials. Furthermore, the contralateral Aßδ-fibers presynaptically control ipsilateral C-fiber input to Lamina I neurons. Thus, these results show that some lumbar Lamina I neurons are wired to the contralateral afferent system whose input, under normal conditions, is subject to inhibitory control. A pathologic disinhibition of the decussating pathways can open a gate controlling contralateral information flow to the nociceptive projection neurons and, thus, contribute to induction of hypersensitivity and mirror-image pain.SIGNIFICANCE STATEMENT We show that contralateral Aδ-afferents and C-afferents supply lumbar Lamina I neurons. The contralateral input is under diverse forms of inhibitory control and itself controls the ipsilateral input. Disinhibition of decussating pathways increases nociceptive drive to Lamina I neurons and may cause induction of contralateral hypersensitivity and mirror-image pain.


Asunto(s)
Asta Dorsal de la Médula Espinal , Médula Espinal , Femenino , Masculino , Ratas , Animales , Dolor , Fibras Nerviosas Amielínicas/fisiología , Interneuronas , Nociceptores/fisiología , Neuronas Aferentes/fisiología , Vías Aferentes/fisiología
2.
Int J Mol Sci ; 25(15)2024 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-39126078

RESUMEN

Epigenetic mechanisms, including histone post-translational modifications (PTMs), play a critical role in regulating pain perception and the pathophysiology of burn injury. However, the epigenetic regulation and molecular mechanisms underlying burn injury-induced pain remain insufficiently explored. Spinal dynorphinergic (Pdyn) neurons contribute to heat hyperalgesia induced by severe scalding-type burn injury through p-S10H3-dependent signaling. Beyond p-S10H3, burn injury may impact various other histone H3 PTMs. Double immunofluorescent staining and histone H3 protein analyses demonstrated significant hypermethylation at H3K4me1 and H3K4me3 sites and hyperphosphorylation at S10H3 within the spinal cord. By analyzing Pdyn neurons in the spinal dorsal horn, we found evidence of chromatin activation with a significant elevation in p-S10H3 immunoreactivity. We used RNA-seq analysis to compare the effects of burn injury and formalin-induced inflammatory pain on spinal cord transcriptomic profiles. We identified 98 DEGs for burn injury and 86 DEGs for formalin-induced inflammatory pain. A limited number of shared differentially expressed genes (DEGs) suggest distinct central pain processing mechanisms between burn injury and formalin models. KEGG pathway analysis supported this divergence, with burn injury activating Wnt signaling. This study enhances our understanding of burn injury mechanisms and uncovers converging and diverging pathways in pain models with different origins.


Asunto(s)
Quemaduras , Epigénesis Genética , Histonas , Nocicepción , Médula Espinal , Animales , Quemaduras/complicaciones , Quemaduras/metabolismo , Quemaduras/genética , Ratones , Histonas/metabolismo , Médula Espinal/metabolismo , Médula Espinal/patología , Masculino , Ratones Endogámicos C57BL , Procesamiento Proteico-Postraduccional , Modelos Animales de Enfermedad
3.
Environ Geochem Health ; 46(10): 409, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39215896

RESUMEN

Due to water shortages and the potential impact of Ethiopia's new dam on the Nile River, Egypt is seeking new water resources. This study assesses the drinking water quality and associated risks from potentially toxic elements (PTEs) in the Quaternary aquifer (QA) in Beni-Suef, Egypt. Using a comprehensive approach, including PHREEQC geochemical modeling, ionic ratios, multivariate statistical analyses, and the integrated weight water quality index (WQI), the study evaluated the sources of ion contamination and the mixing of Nile water with QA. Various indices, such as the Heavy Metal Pollution Index (HPI), ecological Risk Index (RI), Hazard Quotient (HQ), and Hazard Index (HI), were used to assess ecological and health risks. Monte Carlo simulations provided probabilistic assessments of non-carcinogenic risks for adults and children. GIS tools were used to map risk indices, identifying the most deteriorated locations for sustainable management. The hydrochemical analysis revealed water facies including Na-Cl, Ca-Mg-HCO3, and mixed types, influenced by carbonate dissolution, ion exchange, and silicate weathering. Contamination sources, particularly in the north and south, were linked to agricultural activities, irrigation return flow, municipal waste, and evaporation. The WQI indicated that 10.14% of samples were extremely poor, 21.7% were poor, 26% were medium, and 42% were good to excellent. PTE contamination varied, with HPI values indicating good water quality in the central area in 53.6% of the collected samples (HPI < 30), but contamination in the north and south is high (HPI > 51). Ecological Risk Index values were below the threshold in 100% of samples (RI < 30), confirming water safety regarding PTEs. In comparison, for hazard index (HI) through oral/ingestion, adults exhibited HI values ranging from 0.012 to 2.16, while children showed higher values, ranging from 0.045 to 8.25. However, the hazard index for oral/ingestion exceeded safe limits in the north and south (HI oral > 1), posing non-carcinogenic risks. Monte Carlo simulations revealed significant risks from oral exposure to manganese (HQ oral > 1), particularly in El-Wasta and El-Fashn, necessitating further treatment and management.


Asunto(s)
Contaminantes Químicos del Agua , Calidad del Agua , Medición de Riesgo/métodos , Contaminantes Químicos del Agua/análisis , Humanos , Egipto , Monitoreo del Ambiente/métodos , Método de Montecarlo , Agua Subterránea/química , Metales Pesados/análisis , Agua Potable/química , Simulación por Computador
4.
Int J Mol Sci ; 23(6)2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35328599

RESUMEN

Burn injury is a trauma resulting in tissue degradation and severe pain, which is processed first by neuronal circuits in the spinal dorsal horn. We have recently shown that in mice, excitatory dynorphinergic (Pdyn) neurons play a pivotal role in the response to burn-injury-associated tissue damage via histone H3.1 phosphorylation-dependent signaling. As Pdyn neurons were mostly associated with mechanical allodynia, their involvement in thermonociception had to be further elucidated. Using a custom-made AAV9_mutH3.1 virus combined with the CRISPR/cas9 system, here we provide evidence that blocking histone H3.1 phosphorylation at position serine 10 (S10) in spinal Pdyn neurons significantly increases the thermal nociceptive threshold in mice. In contrast, neither mechanosensation nor acute chemonociception was affected by the transgenic manipulation of histone H3.1. These results suggest that blocking rapid epigenetic tagging of S10H3 in spinal Pdyn neurons alters acute thermosensation and thus explains the involvement of Pdyn cells in the immediate response to burn-injury-associated tissue damage.


Asunto(s)
Quemaduras , Histonas , Animales , Quemaduras/genética , Sistemas CRISPR-Cas/genética , Histonas/genética , Histonas/metabolismo , Hiperalgesia/metabolismo , Ratones , Mutagénesis , Neuronas/metabolismo , Médula Espinal/metabolismo
5.
Int J Mol Sci ; 22(21)2021 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-34768839

RESUMEN

Our earlier findings revealed that interleukin-1 receptor type-1 (IL-1R1) was overexpressed in spinal neurons, and IL-1R1-deficient mice showed significant attenuation of thermal and mechanical allodynia during the course of the Complete Freund adjuvant (CFA)-induced persistent pain model. In the present study, we found that a ligand of IL-1R1, termed interleukin-1ß (IL-1ß), is also significantly overexpressed at the peak of mechanical pain sensitivity in the CFA-evoked pain model. Analysis of cellular distribution and modeling using IMARIS software showed that in the lumbar spinal dorsal horn, IL-1ß is significantly elevated by astrocytic expression. Maturation of IL-1ß to its active form is facilitated by the formation of the multiprotein complex called inflammasome; thus, we tested the expression of NOD-like receptor proteins (NLRPs) in astrocytes. At the peak of mechanical allodynia, we found expression of the NLRP2 inflammasome sensor and its significantly elevated co-localization with the GFAP astrocytic marker, while NLRP3 was moderately present and NLRP1 showed total segregation from the astrocytic profiles. Our results indicate that peripheral CFA injection induces NLRP2 inflammasome and IL-1ß expression in spinal astrocytes. The release of mature IL-1ß can contribute to the maintenance of persistent pain by acting on its neuronally expressed receptor, which can lead to altered neuronal excitability.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Astrocitos/metabolismo , Hiperalgesia/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Astrocitos/fisiología , Adyuvante de Freund/farmacología , Expresión Génica/genética , Hiperalgesia/fisiopatología , Inflamasomas/metabolismo , Inflamación/metabolismo , Interleucina-1beta/metabolismo , Masculino , Neuronas/metabolismo , Dolor/metabolismo , Dolor/fisiopatología , Umbral del Dolor/fisiología , Ratas , Ratas Endogámicas WKY , Receptores Tipo I de Interleucina-1/metabolismo , Médula Espinal/metabolismo , Asta Dorsal de la Médula Espinal/metabolismo
6.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33669046

RESUMEN

The phosphorylation of serine 10 in histone 3 (p-S10H3) has recently been demonstrated to participate in spinal nociceptive processing. However, superficial dorsal horn (SDH) neurons involved in p-S10H3-mediated nociception have not been fully characterized. In the present work, we combined immunohistochemistry, in situ hybridization with the retrograde labeling of projection neurons to reveal the subset of dorsal horn neurons presenting an elevated level of p-S10H3 in response to noxious heat (60 °C), causing burn injury. Projection neurons only represented a small percentage (5%) of p-S10H3-positive cells, while the greater part of them belonged to excitatory SDH interneurons. The combined immunolabeling of p-S10H3 with markers of already established interneuronal classes of the SDH revealed that the largest subset of neurons with burn injury-induced p-S10H3 expression was dynorphin immunopositive in mice. Furthermore, the majority of p-S10H3-expressing dynorphinergic neurons proved to be excitatory, as they lacked Pax-2 and showed Lmx1b-immunopositivity. Thus, we showed that neurochemically heterogeneous SDH neurons exhibit the upregulation of p-S10H3 shortly after noxious heat-induced burn injury and consequential tissue damage, and that a dedicated subset of excitatory dynorphinergic neurons is likely a key player in the development of central sensitization via the p-S10H3 mediated pathway.


Asunto(s)
Quemaduras/metabolismo , Histonas/metabolismo , Nocicepción/fisiología , Dolor/metabolismo , Células del Asta Posterior/metabolismo , Serina/metabolismo , Médula Espinal/metabolismo , Animales , Epigénesis Genética , Femenino , Inmunohistoquímica , Hibridación in Situ , Proteínas con Homeodominio LIM/metabolismo , Masculino , Ratones , Ratones Transgénicos , Factor de Transcripción PAX2/metabolismo , Fosforilación , Ratas , Ratas Wistar , Médula Espinal/citología , Médula Espinal/fisiología , Factores de Transcripción/metabolismo
7.
Int J Mol Sci ; 22(19)2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34638769

RESUMEN

The chemical milieu, microbiota composition, and immune activity show prominent differences in distinct healthy skin areas. The objective of the current study was to compare the major permeability barrier components (stratum corneum and tight junction (TJ)), investigate the distribution of (corneo)desmosomes and TJs, and measure barrier function in healthy sebaceous gland-rich (SGR), apocrine gland-rich (AGR), and gland-poor (GP) skin regions. Molecules involved in cornified envelope (CE) formation, desquamation, and (corneo)desmosome and TJ organization were investigated at the mRNA and protein levels using qRT-PCR and immunohistochemistry. The distribution of junction structures was visualized using confocal microscopy. Transepidermal water loss (TEWL) functional measurements were also performed. CE intracellular structural components were similarly expressed in gland-rich (SGR and AGR) and GP areas. In contrast, significantly lower extracellular protein levels of (corneo)desmosomes (DSG1 and CDSN) and TJs (OCLN and CLDN1) were detected in SGR/AGR areas compared to GP areas. In parallel, kallikrein proteases were significantly higher in gland-rich regions. Moreover, gland-rich areas were characterized by prominently disorganized junction structures ((corneo)desmosomes and TJs) and significantly higher TEWL levels compared to GP skin, which exhibited a regular distribution of junction structures. According to our findings, the permeability barrier of our skin is not uniform. Gland-rich areas are characterized by weaker permeability barrier features compared with GP regions. These findings have important clinical relevance and may explain the preferred localization of acantholytic skin diseases on gland-rich skin regions (e.g., Pemphigus foliaceus, Darier's disease, and Hailey-Hailey disease).


Asunto(s)
Acantólisis/metabolismo , Epidermis/metabolismo , Glándulas Sebáceas/metabolismo , Uniones Estrechas/metabolismo , Acantólisis/patología , Adulto , Anciano , Epidermis/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Permeabilidad , Glándulas Sebáceas/patología , Uniones Estrechas/patología
8.
J Nat Prod ; 83(2): 268-276, 2020 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-32077277

RESUMEN

In a search for new secondary metabolites from mosses, leucobryns A-E, axially chiral 9,10-phenanthrenequinone dimers, were isolated from Paraleucobryum longifolium (1-5), together with diosmetin triglycoside. Leucobryns B (2) and C (3) were proved to be homodimeric atropodiastereomers containing both axial and central chirality elements, while leucobryns D (4) and E (5) were found to be heterodimeric atropodiastereomers containing central chirality in only one of the two monomeric units. Axial chirality of the compounds was determined by ECD measurements and sTDA ECD calculations, while the central chirality elements were assigned by TDDFT-SOR calculations. Leucobryns represent the first 9,10-phenanthrenequinone dimers, the monomers of which are linked through their C-8 atoms. Leucobryns B-E contain an uncommon C10 monoterpenoid side chain, in which isoprenoid units are joined by 3,4 linkages. Leucobryns A and B exhibited weak antiproliferative activity against several human cancer cell lines.


Asunto(s)
Briófitas/química , Flavonoides/química , Fenantrenos/aislamiento & purificación , Flavonoides/metabolismo , Humanos , Estructura Molecular , Fenantrenos/química
9.
Eur Respir J ; 53(6)2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31023847

RESUMEN

Our systematic analysis of anion channels and transporters in idiopathic pulmonary arterial hypertension (IPAH) showed marked upregulation of the Cl- channel TMEM16A gene. We hypothesised that TMEM16A overexpression might represent a novel vicious circle in the molecular pathways causing pulmonary arterial hypertension (PAH).We investigated healthy donor lungs (n=40) and recipient lungs with IPAH (n=38) for the expression of anion channel and transporter genes in small pulmonary arteries and pulmonary artery smooth muscle cells (PASMCs).In IPAH, TMEM16A was strongly upregulated and patch-clamp recordings confirmed an increased Cl- current in PASMCs (n=9-10). These cells were depolarised and could be repolarised by TMEM16A inhibitors or knock-down experiments (n=6-10). Inhibition/knock-down of TMEM16A reduced the proliferation of IPAH-PASMCs (n=6). Conversely, overexpression of TMEM16A in healthy donor PASMCs produced an IPAH-like phenotype. Chronic application of benzbromarone in two independent animal models significantly decreased right ventricular pressure and reversed remodelling of established pulmonary hypertension.Our findings suggest that increased TMEM16A expression and activity comprise an important pathologic mechanism underlying the vasoconstriction and remodelling of pulmonary arteries in PAH. Inhibition of TMEM16A represents a novel therapeutic approach to reverse remodelling in PAH.


Asunto(s)
Anoctamina-1/metabolismo , Hipertensión Pulmonar Primaria Familiar/metabolismo , Miocitos del Músculo Liso/metabolismo , Proteínas de Neoplasias/metabolismo , Remodelación Vascular , Vasoconstricción , Adulto , Anciano , Animales , Anoctamina-1/genética , Estudios de Casos y Controles , Proliferación Celular , Modelos Animales de Enfermedad , Hipertensión Pulmonar Primaria Familiar/patología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Músculo Liso Vascular/fisiopatología , Miocitos del Músculo Liso/patología , Proteínas de Neoplasias/genética , Técnicas de Placa-Clamp , Arteria Pulmonar/fisiopatología , Ratas , Ratas Sprague-Dawley , Regulación hacia Arriba
11.
Molecules ; 23(7)2018 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-29937511

RESUMEN

One-hundred and sixty-eight aqueous and organic extracts of 42 selected bryophyte species were screened in vitro for antiproliferative activity on a panel of human gynecological cancer cell lines containing HeLa (cervix epithelial adenocarcinoma), A2780 (ovarian carcinoma), and T47D (invasive ductal breast carcinoma) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and for antibacterial activity on 11 strains using the disc-diffusion method. A total of 99 extracts derived from 41 species exerted ≥25% inhibition of proliferation of at least one of the cancer cell lines at 10 µg/mL. In the cases of Brachythecium rutabulum, Encalypta streptocarpa, Climacium dendroides, Neckera besseri, Pleurozium schreberi, and Pseudoleskeella nervosa, more than one extract was active in the antiproliferative assay, whereas the highest activity was observed in the case of Paraleucobryum longifolium. From the tested families, Brachytheciaceae and Amblystegiaceae provided the highest number of antiproliferative extracts. Only 19 samples of 15 taxa showed moderate antibacterial activity, including the most active Plagiomnium cuspidatum, being active on 8 tested strains. Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus were the most susceptible to the assayed species. This is the first report on the bioactivities of these 14 species.


Asunto(s)
Antiinfecciosos/farmacología , Antineoplásicos Fitogénicos/farmacología , Briófitas/química , Extractos Vegetales/farmacología , Antiinfecciosos/química , Antineoplásicos Fitogénicos/química , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/crecimiento & desarrollo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/patología , Femenino , Humanos , Concentración 50 Inhibidora , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Moraxella catarrhalis/efectos de los fármacos , Moraxella catarrhalis/crecimiento & desarrollo , Extractos Vegetales/química
12.
Stem Cells ; 33(3): 726-41, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25388207

RESUMEN

Retinoids are morphogens and have been implicated in cell fate commitment of embryonic stem cells (ESCs) to neurons. Their effects are mediated by RAR and RXR nuclear receptors. However, transcriptional cofactors required for cell and gene-specific retinoid signaling are not known. Here we show that protein arginine methyl transferase (PRMT) 1 and 8 have key roles in determining retinoid regulated gene expression and cellular specification in a multistage neuronal differentiation model of murine ESCs. PRMT1 acts as a selective modulator, providing the cells with a mechanism to reduce the potency of retinoid signals on regulatory "hotspots." PRMT8 is a retinoid receptor target gene itself and acts as a cell type specific transcriptional coactivator of retinoid signaling at later stages of differentiation. Lack of either of them leads to reduced nuclear arginine methylation, dysregulated neuronal gene expression, and altered neuronal activity. Importantly, depletion of PRMT8 results in altered expression of a distinct set of genes, including markers of gliomagenesis. PRMT8 is almost entirely absent in human glioblastoma tissues. We propose that PRMT1 and PRMT8 serve as a rheostat of retinoid signaling to determine neuronal cell specification in a context-dependent manner and might also be relevant in the development of human brain malignancy.


Asunto(s)
Células Madre Embrionarias/citología , Neuronas/citología , Proteína-Arginina N-Metiltransferasas/metabolismo , Receptores de Ácido Retinoico/metabolismo , Animales , Diferenciación Celular/fisiología , Línea Celular Tumoral , Células Madre Embrionarias/enzimología , Células Madre Embrionarias/metabolismo , Expresión Génica , Glioblastoma , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Neuronas/enzimología , Neuronas/metabolismo , Proteína-Arginina N-Metiltransferasas/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Transducción de Señal
14.
J Physiol ; 592(7): 1519-34, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24421354

RESUMEN

Spinal lamina I is a key element of the pain processing system which relays primary afferent input to supraspinal areas. However, little is known about how the signal is modulated by its intrinsic network including local-circuit neurones (LCNs) and much less numerous anterolateral tract projection neurones (PNs). Here, we used whole-cell patch clamp recordings in an isolated spinal cord preparation to examine properties of identified LCNs (n = 85) and PNs (n = 73) in their functionally preserved local networks. Forty LCNs showed spontaneous rhythmic firing (2-7 Hz) at zero current injection, which persisted in the presence of blockers of fast synaptic transmission. In the remaining cases, most LCNs and PNs fired tonically in response to depolarizing current injections. We identified LCNs and PNs receiving low-threshold primary afferent-driven inhibitory inputs, which in many cases were disynaptic and temporally preceded classical high-threshold excitatory inputs. This direct inhibitory link between low-threshold afferents and PNs can function as a postsynaptic gate controlling the nociceptive information flow in the spinal cord. The LCNs were found to be integrated into the superficial dorsal horn network by their receipt of monosynaptic and disynaptic inputs from other lamina I and II neurones. One-third of LCNs and two-thirds of PNs tested responded to substance P application. Thus, substance P released by a noxious afferent stimulation may excite PNs in two ways: directly, and via the activation of presynaptic LCN circuitries. In conclusion, we have described important properties of identified lamina I neurones and their roles in a new circuit for gating pain responses.


Asunto(s)
Inhibición Neural , Percepción del Dolor , Dolor/fisiopatología , Transducción de Señal , Asta Dorsal de la Médula Espinal/fisiopatología , Animales , Estimulación Eléctrica , Potenciales Postsinápticos Excitadores , Glicina/metabolismo , Técnicas In Vitro , Potenciales Postsinápticos Inhibidores , Inhibición Neural/efectos de los fármacos , Vías Nerviosas/fisiopatología , Dolor/metabolismo , Periodicidad , Ratas Wistar , Tiempo de Reacción , Transducción de Señal/efectos de los fármacos , Asta Dorsal de la Médula Espinal/efectos de los fármacos , Asta Dorsal de la Médula Espinal/metabolismo , Sustancia P/farmacología , Transmisión Sináptica , Factores de Tiempo , Ácido gamma-Aminobutírico/metabolismo
15.
J Neurophysiol ; 111(7): 1507-18, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24431401

RESUMEN

Despite the importance and significant clinical impact of understanding information processing in the nociceptive system, the functional properties of neurons in many parts of this system are still unknown. In this work we performed whole cell patch-clamp recording in rat brain stem blocks to characterize the electrophysiological properties of neurons in the dorsal reticular nucleus (DRt), a region known to be involved in pronociceptive modulation. We also compared properties of DRt neurons with those in the adjacent parvicellular reticular nucleus and in neighboring regions outside the reticular formation. We found that neurons in the DRt and parvicellular reticular nucleus had similar electrophysiological properties and exhibited mostly toniclike firing patterns, whereas neurons outside the reticular formation showed a larger diversity of firing patterns. Interestingly, more than one-half of the neurons also showed spontaneous activity. While the general view of the reticular formation, being a loosely associated mesh of groups of neurons with diverse function, and earlier reports suggests more electrophysiological heterogeneity, we showed that this is indeed not the case. Our results indicate that functional difference of neurons in the reticular formation may mostly be determined by their connectivity profiles and not by their intrinsic electrophysiological properties. The dominance of tonic neurons in the DRt supports previous conclusions that these neurons encode stimulus intensity through their firing frequency, while the high prevalence of spontaneous activity most likely shapes nociceptive modulation by this brain stem region.


Asunto(s)
Potenciales de la Membrana/fisiología , Red Nerviosa/fisiología , Neuronas/fisiología , Nocicepción/fisiología , Formación Reticular/citología , Animales , Animales Recién Nacidos , Biofisica , Cobalto/farmacología , Simulación por Computador , Estimulación Eléctrica , Modelos Neurológicos , Vías Nerviosas , Técnicas de Placa-Clamp , Ratas , Ratas Wistar , Potenciales Sinápticos/fisiología
16.
Neuropharmacology ; 247: 109858, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38286189

RESUMEN

The most superficial layer of the spinal dorsal horn, lamina I, is a key element of the nociceptive processing system. It contains different types of projection neurons (PNs) and local-circuit neurons (LCNs) whose functional roles in the signal processing are poorly understood. This article reviews recent progress in elucidating novel anatomical features and physiological properties of lamina I PNs and LCNs revealed by whole-cell recordings in ex vivo spinal cord. This article is part of the Special Issue on "Ukrainian Neuroscience".


Asunto(s)
Neuronas , Asta Dorsal de la Médula Espinal , Interneuronas/fisiología , Células del Asta Posterior
17.
Sci Rep ; 14(1): 7314, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38538675

RESUMEN

This research presents an unsupervised learning approach for interpreting well-log data to characterize the hydrostratigraphical units within the Quaternary aquifer system in  Debrecen area, Eastern Hungary. The study applied factor analysis (FA) to extract factor logs from spontaneous potential (SP), natural gamma ray (NGR), and resistivity (RS) logs and correlate it to the petrophysical and hydrogeological parameters of shale volume and hydraulic conductivity. This research indicated a significant exponential relationship between the shale volume and the scaled first factor derived through factor analysis. As a result, a universal FA-based equation for shale volume estimation is derived that shows a close agreement with the deterministic shale volume estimation. Furthermore, the first scaled factor is correlated to the decimal logarithm of hydraulic conductivity estimated with the Csókás method. Csókás method is modified from the Kozeny-Carman equation that continuously estimates the hydraulic conductivity. FA and Csókás method-based estimations showed high similarity with a correlation coefficient of 0.84. The use of factor analysis provided a new strategy for geophysical well-logs interpretation that bridges the gap between traditional and data-driven machine learning techniques. This approach is beneficial in characterizing heterogeneous aquifer systems for successful groundwater resource development.

18.
Front Cell Neurosci ; 18: 1382465, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38784707

RESUMEN

The endogenous cannabinoid 2-arachidonoylglycerol (2-AG) influences neurotransmission in the central nervous system mainly by activating type 1 cannabinoid receptor (CB1). Following its release, 2-AG is broken down by hydrolases to yield arachidonic acid, which may subsequently be metabolized by cyclooxygenase-2 (COX-2). COX-2 converts arachidonic acid and also 2-AG into prostanoids, well-known inflammatory and pro-nociceptive mediators. Here, using immunohistochemical and biochemical methods and pharmacological manipulations, we found that reactive spinal astrocytes and microglia increase the expression of COX-2 and the production of prostaglandin E2 when exposed to 2-AG. Both 2-AG and PGE2 evoke calcium transients in spinal astrocytes, but PGE2 showed 30% more efficacy and 55 times more potency than 2-AG. Unstimulated spinal dorsal horn astrocytes responded to 2-AG with calcium transients mainly through the activation of CB1. 2-AG induced exaggerated calcium transients in reactive astrocytes, but this increase in the frequency and area under the curve of calcium signals was only partially dependent on CB1. Instead, aberrant calcium transients were almost completely abolished by COX-2 inhibition. Our results suggest that both reactive spinal astrocytes and microglia perform an endocannabinoid-prostanoid switch to produce PGE2 at the expense of 2-AG. PGE2 in turn is responsible for the induction of aberrant astroglial calcium signals which, together with PGE2 production may play role in the development and maintenance of spinal neuroinflammation-associated disturbances such as central sensitization.

19.
Sci Rep ; 14(1): 1008, 2024 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-38200086

RESUMEN

This study assessed the environmental and health risks associated with heavy metals in the water resources of Egypt's northwestern desert. The current approaches included the Spearman correlation matrix, principal component analysis, and cluster analysis to identify pollution sources and quality-controlling factors. Various indices (HPI, MI, HQ, HI, and CR) were applied to evaluate environmental and human health risks. Additionally, the Monte Carlo method was employed for probabilistic carcinogenic and non-carcinogenic risk assessment via oral and dermal exposure routes in adults and children. Notably, all water resources exhibited high pollution risks with HPI and MI values exceeding permissible limits (HPI > 100 and MI > 6), respectively. Furthermore, HI oral values indicated significant non-carcinogenic risks to both adults and children, while dermal contact posed a high risk to 19.4% of samples for adults and 77.6% of samples for children (HI > 1). Most water samples exhibited CR values exceeding 1 × 10-4 for Cd, Cr, and Pb, suggesting vulnerability to carcinogenic effects in both age groups. Monte Carlo simulations reinforced these findings, indicating a significant carcinogenic impact on children and adults. Consequently, comprehensive water treatment measures are urgently needed to mitigate carcinogenic and non-carcinogenic health risks in Siwa Oasis.


Asunto(s)
Agua Subterránea , Metales Pesados , Adulto , Niño , Humanos , Método de Montecarlo , Recursos Hídricos , Metales Pesados/toxicidad , Carcinogénesis , Carcinógenos , Medición de Riesgo
20.
Sci Rep ; 14(1): 18639, 2024 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-39128943

RESUMEN

Evaluation of water quality is crucial for managing surface water effectively, ensuring its suitability for human use, and sustaining the environment. In the lower Danube River basin, various methods were employed to assess surface water quality for irrigation, drinking, human health risk purposes and the main mechanism control the surface water chemistry. These methods included water quality indicators (WQIs), complex statistical analyses, geographic information systems (GIS), Monte Carlo simulation, and geochemical modeling. Physicochemical analyses of surface water samples revealed primarily Ca-Mg-HCO3- is the dominant water types. Principal component analysis (PCA), ionic ratios and piper, chloro alkaline index, Chadha, and Gibbs diagrams identified three distinct water characteristics influenced by water-rocks interaction, evaporation, ions exchange, and human activities. The geochemical modeling showed Danube River water's strong ability to dissolve gypsum, halite, and anhydrite (SI < 0) and precipitate aragonite, dolomite, and calcite with saturation index (SI) value greater than 0 along its flow path. The irrigation water quality index (IWQI = 99.6-107.6), sodium adsorption ratio (SAR = 0.37-0.68), sodium percentage (Na% = 13.7-18.7), soluble sodium percentage (SSP = 12.5-17.5), Potential Salinity (PS = 0.73-1.6), and Residual Sodium Carbonate (RSC = - 1.27-0.58) values were used, mainly indicating acceptable quality with some limitations. Danube River water was unsuitable for drinking based on WQI value (WQI = 81-104). Oral exposure of children to specific components showed a higher hazard index (HI > 1) compared to adults, indicating a 2.1 times higher overall non-carcinogenic risk hazard index. However, Monte Carlo simulation demonstrated negligible iron, manganese, and nitrate health hazards for both age groups. These findings are valuable for water quality management decisions, contributing to long-term resource sustainability.

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