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1.
Front Pharmacol ; 15: 1384834, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38751780

RESUMO

Introduction: Administration of high doses of acetaminophen (APAP) results in liver injury. Oxidative stress and iron overload play roles in the pathogenesis of APAP-induced hepatotoxicity. The present study assessed the potential hepatoprotective effects of phytic acid (PA), a natural antioxidant and iron chelator, on APAP-induced hepatotoxicity and the possible underlying mechanism through its effects on CYP2E1 gene expression, iron homeostasis, oxidative stress, and SIRT-1 expression levels. Methods: Twenty-four adult male albino mice were used in this study. Mice were divided into four groups (six mice in each group): control, APAP-treated, PA-treated and APAP + PA-treated groups. Liver function tests, serum and liver tissue iron load were evaluated in all the study groups. Hepatic tissue homogenates were used to detect oxidative stress markers, including malondialdehyde (MDA) and reduced glutathione (GSH). Histological hepatic evaluation and immunohistochemistry of SIRT-1 were performed. Quantitative real-time PCR was used for the assessment of CYP2E1 and SIRT-1 gene expressions. APAP-induced biochemical and structural hepatic changes were reported. Results: PA administration showed beneficial effects on APAP-induced hepatotoxicity through improvements in liver functions, decreased CYP2E1 gene expression, decreased serum and liver iron load, decreased MDA, increased GSH, increased SIRT-1 expression level and improvement in hepatic architecture. Conclusion: Conclusively, PA can be considered a potential compound that can attenuate acetaminophen-induced hepatotoxicity through its role as an iron chelator and antioxidant, as well as the up-regulation of SIRT-1 and down-regulation of CYP2E1.

2.
Tissue Cell ; 84: 102192, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37579617

RESUMO

Aging is a highly complicated natural process. Brain aging is associated with remarkable neurodegenerative changes and oxidative damage. Whey protein (WP) has been mentioned to have an antioxidant property. Nuclear factor erythrogen-2 associated factor 2 (Nrf2) signaling pathway is an antioxidant defense system. Nrf2 activity declines with age so, its activation could be a promising therapeutic strategy for aging. This study aimed to explore the anti-aging role of WP against D-galactose (D-gal) induced age-related degenerative changes and oxidative damage in the prefrontal cortex (PFC) and investigate its underlying mechanisms. Forty adult male rats were divided into 4 groups; control, WP group received WP (28.77 mg/kg/day) by gastric tube on the 4th experimental week; D-gal (model group) received D-gal (300 mg/kg/day) intraperitoneally for 8 weeks and D-gal +WP group received WP on the 4th week of D-gal treatment. Specimens from PFC were obtained for biochemical, histological, immunohistochemical and western blot analysis. WP treatment in D-gal +WP group reduced lipid peroxidation, enhanced antioxidant enzyme activities, decreased advanced glycation end products level and improved the histological and ultrastructural alterations. Moreover, the number of neurons expressed the senescence marker; p21 and percentage area of the astrocytic marker; glial fibrillary acidic protein were significantly reduced. WP also enhanced Nrf2 pathway and its downstream targets; heme oxygenase-1 and NADPH quinone oxidoreductase 1. In conclusion WP alleviates the D-gal-induced PFC aging through activating Nrf2 pathway, reducing cell senescence and gliosis. So, it may be a potential therapeutic target to retard the aging process.


Assuntos
Antioxidantes , Fator 2 Relacionado a NF-E2 , Ratos , Masculino , Animais , Antioxidantes/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas do Soro do Leite/farmacologia , Proteínas do Soro do Leite/metabolismo , Envelhecimento/metabolismo , Estresse Oxidativo , Transdução de Sinais , Córtex Pré-Frontal/metabolismo , Galactose/farmacologia
3.
Int Urol Nephrol ; 55(1): 129-139, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35817991

RESUMO

BACKGROUND: Hemorrhagic cystitis often develops in patients treated with cyclophosphamide (CP). Vincamine (vinca alkaloid) is the source of the synthetic derivative vinpocetine (Vinpo). Worldwide, Vinpo is used as a cerebroprotective drug. As it has anti-oxidant, anti-thrombotic and anti-inflammatory effects but the power of Vinpo to prevent CP induced cystitis has not been studied. AIM OF STUDY: This research was planned to explore the effect of Vinpo (10-30 mg/kg, orally) administered 1 or 4 h before inducing cystitis by CP injection (300 mg/kg, i.p.) on the urinary bladder of mice. RESULTS: Administration of Vinpo 30 mg/kg, 4 h before CP injection ameliorated inflammatory markers. It reduced inducible nitric oxide synthase (iNOS), tumor necrosis factor- α (TNF-α), and BCL2 Associated X (Bax) expression in the bladder and increased the total antioxidant capacity level. Histological examination of the bladder has further supported these results. The present study suggests a protective effect of Vinpo (30 mg/kg, 4 h before CP injection) against CP-induced bladder inflammation. CONCLUSION: This proposes that Vinpo 30 mg/kg may become a promising pharmacological drug to prevent urinary adverse effects in patients treated with chemotherapy using CP.


Assuntos
Cistite , Alcaloides de Vinca , Camundongos , Animais , Bexiga Urinária/patologia , Ciclofosfamida/efeitos adversos , Estresse Oxidativo , Cistite/induzido quimicamente , Cistite/tratamento farmacológico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Alcaloides de Vinca/farmacologia , Alcaloides de Vinca/uso terapêutico , Apoptose
4.
Front Mol Biosci ; 10: 1306523, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38357327

RESUMO

Background: High-fat diet-induced obesity is linked to suppression of aquaporins (AQPs) expression in different tissues. Both vitamin D and intermittent fasting were identified to enhance AQPs expression. In the urinary bladder, AQP-1 and AQP-3 mRNA transcripts were identified. Vitamin D has an impact on a variety of genes that encode proteins that control cell proliferation, differentiation, and death. Aim: To assess potential benefits of vitamin D and intermittent fasting (IF) and to explore alterations to the urinary bladder triggered by high-fat diet (HFD) in a rat model of obesity. Methods: Each of the 4 groups contained six adult male albino rats; control: a standard rodent chew for 12 weeks, HFD: HFD and fructose were administered orally via gastric gavage for 12 weeks, and vitamin D: HFD and fructose were administered orally for 8 weeks, then 4 weeks of intraperitoneal injection of vitamin D (5 microns/Kg/2 days) and IF group: Received intraperitoneal injections of vitamin D (5 microns/Kg/2 days) for 4 weeks after consumption of HFD and fructose orally for 8 weeks. The serum lipid profile was conducted at end of the experiment. In the bladder homogenates, the levels of oxidative stress indicators were assessed. Quantitative real-time PCR was performed on recently collected bladder samples. AQP-1 and AQP-3 immunohistochemistry was done. Results: When compared to the HFD group, the vitamin D and IF groups both demonstrated a substantial improvement in histopathological, immunohistochemical, biochemical, and molecular markers. Conclusion: In all examined parameters, IF exceeded vitamin D as a preventive factor for the urinary bladder deterioration.

5.
Front Neuroanat ; 16: 1012422, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36312298

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by gradual cognitive decline. Strong antioxidants that inhibit free radicals, such as polyphenols, reduce the likelihood of developing oxidative stress-related degenerative diseases such as AD. Naringin, a flavonoid found in citrus fruit shown to be neuroprotective, reduce oxidative damage and minimize histopathological changes caused by ischemic reperfusion, enhance the long-term memory in AD animal models. This work aimed to comprehend the role of naringin in the defense of the cerebellum against aluminum chloride (AlCl3)-induced AD in rats by investigating the behavioral, neurochemical, immunohistochemical, and molecular mechanisms that underpin its possible neuroprotective effects. Twenty-four adult albino rats were divided into four groups (n = 6/group): (i) Control (C) received saline per oral (p.o.), (ii) Naringin(N)-received naringin (100 mg/kg/d) p.o, (iii) AlCl3-recived AlCl3 (100 mg/kg/d) p.o and (iv) AlCl3 + Naringin (AlCl3 + N) received both AlCl3 and naringin p.o for 21 days. Behavioral tests showed an increase in the time to reach the platform in Morris water maze, indicating memory impairment in the AlCl3-treated group, but co-administration of naringin showed significant improvement. The Rotarod test demonstrated a decrease in muscle coordination in the AlCl3-treated group, while it was improved in the AlCl3 + N group. Neurochemical analysis of the hippocampus and cerebellum revealed that AlCl3 significantly increased lipid peroxidation and oxidative stress and decreased levels of reduced glutathione. Administration of naringin ameliorated these neurochemical changes via its antioxidant properties. Cerebellar immunohistochemical expression for microtubule assembly (tau protein) and oxidative stress (iNOS) increased in A1C13-treated group. On the other hand, the expression of the autophagic marker (LC3) in the cerebellum showed a marked decline in AlCl3-treated group. Western blot analysis confirmed the cerebellar immunohistochemical findings. Collectively, these findings suggested that naringin could contribute to the combat of oxidative and autophagic stress in the cerebellum of AlCl3-induced AD.

6.
Cells ; 10(9)2021 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-34572126

RESUMO

Autophagy is a key metabolic process where cells can recycle its proteins and organelles to regenerate its own cellular building blocks. Chemotherapy is indispensable for cancer treatment but associated with various side-effects, including organ damage. Stem cell-based therapy is a promising approach for reducing chemotherapeutic side effects, however, one of its main culprits is the poor survival of transplanted stem cells in damaged tissues. Here, we aimed to test the effects of activating autophagy in adipose-derived mesenchymal stem/stromal cells (ADSCs) on the survival of ADSCs, and their therapeutic value in cisplatin-induced liver injury model. Autophagy was activated in ADSCs by rapamycin (50 nM/L) for two hours before transplantation and were compared to non-preconditioned ADSCs. Rapamycin preconditioning resulted in activated autophagy and improved survival of ADSCs achieved by increased autophagosomes, upregulated autophagy-specific LC3-II gene, decreased protein degradation/ubiquitination by downregulated p62 gene, downregulated mTOR gene, and finally, upregulated antiapoptotic BCL-2 gene. In addition, autophagic ADSCs transplantation in the cisplatin liver injury model, liver biochemical parameters (AST, ALT and albumin), lipid peroxidation (MDA), antioxidant profile (SOD and GPX) and histopathological picture were improved, approaching near-normal conditions. These promising autophagic ADSCs effects were achieved by modulation of components in TGF-ß1/Smad and PI3K-AKT signaling pathways, besides reducing NF-κB gene expression (marker for inflammation), reducing TGF-ß1 levels (marker for fibrosis) and increasing SDF-1 levels (liver regeneration marker) in liver. Therefore, current results highlight the importance of autophagy in augmenting the therapeutic potential of stem cell therapy in alleviating cisplatin-associated liver damage and opens the path for improved cell-based therapies, in general, and with chemotherapeutics, in particular.


Assuntos
Autofagia , Doença Hepática Crônica Induzida por Substâncias e Drogas/prevenção & controle , Células-Tronco Mesenquimais/citologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Smad/metabolismo , Transplante de Células-Tronco/métodos , Fator de Crescimento Transformador beta1/metabolismo , Animais , Antineoplásicos/toxicidade , Doença Hepática Crônica Induzida por Substâncias e Drogas/etiologia , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Crônica Induzida por Substâncias e Drogas/patologia , Cisplatino/toxicidade , Feminino , Masculino , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Ratos Sprague-Dawley , Proteínas Smad/genética , Fator de Crescimento Transformador beta1/genética
7.
Saudi J Biol Sci ; 28(6): 3391-3398, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34121877

RESUMO

Globally, breast cancer is the most common type of cancer in females and is one of the leading causes of cancer death in women. The advancement in the targeted therapies and the slight understanding of the molecular cascades of the disease have led to small improvement in the rate of survival of breast cancer patients. However, metastasis and resistance to the current drugs still remain as challenges in the management of breast cancer patients. Metastasis, potentially, leads to failure of the available treatment, and thereby, makes the research on metastatic suppressors a high priority. Tumor metastasis suppressors are several genes and their protein products that have the capability of arresting the metastatic process without affecting the tumor formation. The metastasis suppressors KAI1 (also known as CD82) has been found to inhibit tumor metastasis in various types of solid cancers, including breast cancer. KAI1 was identified as a metastasis suppressor that inhibits the process of metastasis by regulating several mechanisms, including cell motility and invasion, induction of cell senescence, cell-cell adhesion and apoptosis. KAI1 is a member of tetraspanin membrane protein family. It interacts with other tetraspanins, chemokines and integrins to control diverse signaling pathways, which are crucial for protein trafficking and intracellular communication. It follows that better understanding of the molecular events of such genes is needed to develop prognostic biomarkers, and to identify specific therapies for breast cancer patients. This review aims to discuss the role of KAI1/CD82 as a prognosticator in breast cancer.

8.
Saudi Med J ; 41(9): 938-946, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32893275

RESUMO

OBJECTIVES: To find reference data for the time of appearance of ossification centers in carpal bones and the lower ends of the radius and ulna in the Saudi population. In addition, to check the sequence of appearance of carpal bones and the relation of this sequence to the appearance of distal epiphyses of the radius and ulna. Methods: A retrospective radiological study was carried out between 2012 to 2020 at King Fahad Hospital of the University, Al-Khobar, Saudi Arabia. A sample of 279 hand/wrist plain radiographs of Saudi children was analyzed. RESULTS: The first bones at the wrist region to appear in Saudi children are the capitate, hamate, and distal epiphysis of the radius, and these appear during the first year of life. The other bones develop subsequently at yearly intervals, and the last one to appear is the pisiform, which arises at the end of the first decade of life. CONCLUSION: The sequence of appearance of carpal bones in the Saudi population is similar to what is described in the literature. However, the time of appearance of some of these bones is earlier than that in other populations.


Assuntos
Desenvolvimento Ósseo/fisiologia , Ossos do Carpo/diagnóstico por imagem , Ossos do Carpo/fisiologia , Osteogênese , Adolescente , Ossos do Carpo/anatomia & histologia , Criança , Pré-Escolar , Epífises , Feminino , Humanos , Lactente , Masculino , Rádio (Anatomia)/anatomia & histologia , Rádio (Anatomia)/diagnóstico por imagem , Estudos Retrospectivos , Arábia Saudita , Caracteres Sexuais , Ulna/anatomia & histologia , Ulna/diagnóstico por imagem
9.
Rev Endocr Metab Disord ; 20(2): 187-195, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31025266

RESUMO

Thyroid gland has been implicated in the regulation of many functions using endocrine, paracrine and autocrine signals. Functional thyroid follicular cells derived from stem cells attracted a great interest from researchers as a strategy for thyroid's regenerative therapy. Thyroid has a very low rate of turnover; however, studies showed that the regenerative ability is enhanced following diseases or thyroidectomy, which promotes the role of stem cell. The objective of this review is to summarize the morphological characterization and the expression of stem cell genes/markers in the thyroid. Also, to highlight the mechanisms of tumor formation in thyroid via its stem cells. The most important thyroid stem cell's markers are: stem cell antigen 1 (SCA-1), octamer-binding transcription 4 (OCT-4), p63, CD34+ CD45-, paired box gene 8 (PAX-8), thyroid transcription factor 1 (TTF-1), thyroid transcription factor 2 (TTF-2), hematopoietically expressed homeobox protein HHEX, the transcription factor GATA-4, hepatocyte nuclear factor 4-α (HNF-4-α) and homeobox transcription factor Nanog (hNanog). This review highlights the functional characterization describing the mechanisms of stem cell's differentiation into functional thyroid follicle and proposing mechanisms involving in cancer formation through one of these cell types: fetal cell, thyroblasts, prothyrocytes, certain genetic mutation in the mature thyroid cells or presence of a special type of cells (cancer stem cell) which are responsible for different types of cancer formation. Understanding the mechanisms of thyroid's stem cell in cancer formation and the expression of the biomarkers in normal and abnormal thyroid status are promising physiological tools in promoting thyroid regeneration and in provision management for thyroid cancer.


Assuntos
Biomarcadores/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Glândula Tireoide/citologia , Animais , Humanos , Células Epiteliais da Tireoide/citologia , Células Epiteliais da Tireoide/metabolismo , Fator Nuclear 1 de Tireoide/metabolismo
10.
Saudi Med J ; 37(5): 521-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27146614

RESUMO

OBJECTIVES: To assess the prevalence of common radiological variants of sinonasal anatomy among Saudi population and compare it with the reported prevalence of these variants in other ethnic and population groups.  METHODS: This is a retrospective cross-sectional study of 121 computerized tomography scans of the nose and paranasal sinuses of patients presented with sinonasal symptoms to the Department of Otorhinolarngology, King Fahad Hospital of the University, Khobar, Saudi Arabia, between January 2014 and May 2014.  RESULTS: Scans of 121 patients fulfilled inclusion criteria were reviewed. Concha bullosa was found in 55.4%, Haller cell in 39.7%, and Onodi cell  in 28.9%. Dehiscence of the internal carotid artery was found in 1.65%. Type-1 and type-2 optic nerve were the prevalent types. Type-II Keros classification of the depth of olfactory fossa was the most common among the sample (52.9%). Frontal cells were found in 79.3%; type I was the most common.   CONCLUSIONS: There is a difference in the prevalence of some radiological variants of the sinonasal anatomy between Saudi population and other study groups. Surgeon must pay special attention in the preoperative assessment of patients with sinonasal pathology to avoid undesirable complications.


Assuntos
Nariz/diagnóstico por imagem , Seios Paranasais/diagnóstico por imagem , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nariz/anatomia & histologia , Seios Paranasais/anatomia & histologia , Prevalência , Estudos Retrospectivos , Arábia Saudita/epidemiologia , Tomografia Computadorizada por Raios X , Adulto Jovem
11.
J Comp Neurol ; 515(6): 629-46, 2009 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-19496168

RESUMO

Projection neurons in lamina I, together with those in laminae III-IV that express the neurokinin 1 receptor (NK1r), form a major route through which nociceptive information reaches the brain. Axons of these cells innervate various targets, including thalamus, periaqueductal gray matter (PAG), and lateral parabrachial area (LPb), and many cells project to more than one target. The aims of this study were to quantify projections from cervical enlargement to PAG and LPb, to determine the proportion of spinothalamic neurons at lumbar and cervical levels that were labelled from PAG and LPb, and to investigate morphological differences between projection populations. The C7 segment contained fewer lamina I spinoparabrachial cells than L4, but a similar number of spino-PAG cells. Virtually all spinothalamic lamina I neurons at both levels were labelled from LPb and between one-third and one-half from PAG. This suggests that significant numbers project to all three targets. Spinothalamic lamina I neurons differed from those labelled only from LPb in that they were generally larger, were more often multipolar, and (in cervical enlargement) had stronger NK1r immunoreactivity. Most lamina III/IV NK1r cells at both levels projected to LPb, but few were labelled from PAG. The great majority of these cells in C7 and over one-fourth of those in L4 were spinothalamic, and at each level some projected to both thalamus and LPb. These results confirm that neurons in these laminae have extensive collateral projections and suggest that different neuronal subpopulations in lamina I have characteristic patterns of supraspinal projection.


Assuntos
Vias Aferentes/anatomia & histologia , Neurônios/citologia , Substância Cinzenta Periaquedutal/anatomia & histologia , Medula Espinal/anatomia & histologia , Tálamo/anatomia & histologia , Animais , Biomarcadores/metabolismo , Proteínas de Transporte/metabolismo , Imuno-Histoquímica , Masculino , Proteínas de Membrana/metabolismo , Ratos , Ratos Wistar , Receptores da Neurocinina-1/metabolismo
12.
J Neurosci ; 28(49): 13150-60, 2008 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-19052206

RESUMO

Although most projection neurons in lamina I express the neurokinin 1 receptor (NK1r), we have identified a population of large multipolar projection cells that lack the NK1r, are characterized by the high density of gephyrin puncta that coat their cell bodies and dendrites, and express the transcription factor Fos in response to noxious chemical stimulation. Here we show that these cells have a very high density of glutamatergic input from axons with strong immunoreactivity for vesicular glutamate transporter 2 that are likely to originate from excitatory interneurons. However, they receive few contacts from peptidergic primary afferents or transganglionically labeled Adelta nociceptors. Unlike most glutamatergic synapses in superficial laminas, those on the gephyrin-coated cells contain the GluR4 subunit of the AMPA receptor. A noxious heat stimulus caused Fos expression in 38% of the gephyrin-coated cells but in 85% of multipolar NK1r-immunoreactive cells. These findings are consistent with the suggestion that there is a correlation between function and morphology for lamina I neurons but indicate that there are at least two populations of multipolar neurons that differ in receptor expression, excitatory inputs, and responses to noxious stimulation. Although there are only approximately 10 gephyrin-coated cells on each side per segment in the lumbar enlargement, they constitute approximately 18% of the lamina I component of the spinothalamic tract at this level, which suggests that they play an important role in transmission of nociceptive information to the cerebral cortex. Our results also provide the first evidence that postsynaptic GluR4-containing AMPA receptors are involved in spinal nociceptive transmission.


Assuntos
Ácido Glutâmico/metabolismo , Nociceptores/metabolismo , Células do Corno Posterior/metabolismo , Terminações Pré-Sinápticas/metabolismo , Receptores de AMPA/metabolismo , Tratos Espinotalâmicos/metabolismo , Animais , Proteínas de Transporte/metabolismo , Forma Celular/fisiologia , Dendritos/metabolismo , Dendritos/ultraestrutura , Imuno-Histoquímica , Interneurônios/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Nociceptores/citologia , Dor/metabolismo , Dor/fisiopatologia , Estimulação Física , Células do Corno Posterior/citologia , Terminações Pré-Sinápticas/ultraestrutura , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Wistar , Receptores da Neurocinina-1/metabolismo , Tratos Espinotalâmicos/citologia , Substância P/metabolismo , Transmissão Sináptica/fisiologia , Proteína Vesicular 2 de Transporte de Glutamato/metabolismo
13.
J Comp Neurol ; 511(1): 1-18, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18720412

RESUMO

The major ascending outputs from superficial spinal dorsal horn consist of projection neurons in lamina I, together with neurons in laminae III-IV that express the neurokinin 1 receptor (NK1r) and have dendrites that enter the superficial laminae. Some neurons in each of these populations belong to the spinothalamic tract, which conveys nociceptive information via the thalamus to cortical areas involved in pain. A projection from the cervical superficial dorsal horn to the posterior triangular nucleus (PoT) has recently been identified. PoT is at the caudal end of the thalamus and was not included in injection sites in many previous retrograde tracing studies. We have injected various tracers (cholera toxin B subunit, Fluoro-Gold, and fluorescent latex microspheres) into the thalamus to estimate the number of spinothalamic neurons in each of these two populations, and to investigate their projection targets. Most lamina I and lamina III/IV NK1r-immunoreactive spinothalamic neurons in cervical and lumbar segments could be labeled from injections centered on PoT. Our results suggest that there are 90 lamina I spinothalamic neurons per side in C7 and 15 in L4 and that some of those in C7 only project to PoT. We found that 85% of the lamina III/IV NK1r-immunoreactive neurons in C6 and 17% of those in L5 belong to the spinothalamic tract, and these apparently project exclusively to the caudal thalamus, including PoT. Because PoT projects to second somatosensory and insular cortices, our results suggest that these are major targets for information conveyed by both these populations of spinothalamic neurons.


Assuntos
Neurônios/citologia , Medula Espinal/citologia , Tratos Espinotalâmicos/anatomia & histologia , Animais , Corantes Fluorescentes/metabolismo , Imuno-Histoquímica , Masculino , Microesferas , Neurônios/metabolismo , Ratos , Ratos Wistar , Estilbamidinas/metabolismo , Tálamo/anatomia & histologia
14.
Eur J Neurosci ; 26(6): 1587-98, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17880393

RESUMO

The dorsal horn of the rat spinal cord contains a population of large neurons with cell bodies in laminae III or IV, that express the neurokinin 1 receptor (NK1r) and have long dorsal dendrites that branch extensively within the superficial laminae. In this study, we have identified a separate population of neurons that have similar dendritic morphology, but lack the NK1r. These cells also differ from the NK1r-expressing neurons in that they have significantly fewer contacts from substance P-containing axons and are not retrogradely labelled following injection of tracer into the caudal ventrolateral medulla. We also provide evidence that these cells do not belong to the postsynaptic dorsal column pathway or the spinothalamic tract. It is therefore likely that these cells do not have supraspinal projections. They may provide a route through which information transmitted by C fibres that lack neuropeptides is conveyed to deeper laminae. The present findings demonstrate the need for caution when attempting to classify neurons solely on the basis of somatodendritic morphology.


Assuntos
Dendritos/fisiologia , Neurônios/fisiologia , Receptores da Neurocinina-1/fisiologia , Medula Espinal/citologia , Medula Espinal/fisiologia , Animais , Axônios/metabolismo , Imuno-Histoquímica , Masculino , Bulbo/citologia , Bulbo/fisiologia , Microscopia Confocal , Proteínas de Neurofilamentos/metabolismo , Neurônios Aferentes/fisiologia , Ratos , Ratos Wistar , Estilbamidinas , Substância P/metabolismo , Tálamo/citologia , Tálamo/fisiologia
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