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1.
Int J Mol Sci ; 22(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068557

RESUMO

Depression is a prominent complex psychiatric disorder, usually complicated through expression of comorbid conditions, with chronic pain being among the most prevalent. This comorbidity is consistently associated with a poor prognosis and has been shown to negatively impact patient outcomes. With a global rise in this condition presenting itself, the importance of discovering long-term, effective, and affordable treatments is crucial. Electroacupuncture has demonstrated renowned success in its use for the treatment of pain and is a widely recognized therapy in clinical practice for the treatment of various psychosomatic disorders, most notably depression. Our study aimed to investigate the effects and mechanisms of Acid-Saline (AS) inducing states of chronic pain and depression comorbidity in the cerebellum, using the ST36 acupoint as the therapeutic intervention. Furthermore, the role of TRPV1 was relatedly explored through the use of TRPV1-/- mice (KO). The results indicated significant differences in the four behavioral tests used to characterize pain and depression states in mice. The AS and AS + SHAM group showed significant differences when compared to the Control and AS + EA groups in the von Frey and Hargreaves's tests, as well as the Open-Field and Forced Swimming tests. This evidence was further substantiated in the protein levels observed in immunoblotting, with significant differences between the AS and AS + SHAM groups when compared to the AS + EA and AS + KO groups being identified. In addition, immunofluorescence visibly served to corroborate the quantitative outcomes. Conclusively these findings suggest that AS-induced chronic pain and depression comorbidity elicits changes in the cerebellum lobules VI, VII, VIII, which are ameliorated through the use of EA at ST36 via its action on TRPV1 and related molecular pathways. The action of TRPV1 is not singular in CPDC, which would suggest other potential targets such as acid-sensing ion channel subtype 3 (ASIC3) or voltage-gated sodium channels (Navs) that could be explored in future studies.


Assuntos
Canais Iônicos Sensíveis a Ácido/genética , Dor Crônica/genética , Depressão/genética , Canais de Cátion TRPV/genética , Ácidos/toxicidade , Pontos de Acupuntura , Animais , Cerebelo/metabolismo , Cerebelo/patologia , Cerebelo/efeitos da radiação , Dor Crônica/induzido quimicamente , Dor Crônica/complicações , Dor Crônica/terapia , Comorbidade , Depressão/complicações , Depressão/patologia , Modelos Animais de Doenças , Eletroacupuntura , Humanos , Camundongos , Camundongos Knockout , Solução Salina/toxicidade , Natação
2.
Mol Biol Rep ; 47(6): 4815-4820, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32388700

RESUMO

Proton beam therapy is widely used for treating brain tumor. Despite the efficacy of treatment, the use of this therapy has met some limitations associated with possible damage to normal brain tissues located beyond the tumor site. In this context, the exploration of the harmful effects of protons on the normal brain tissues is of particular interest. We have investigated changes in the total mitochondrial DNA (mtDNA) copy number and identified mtDNA mutant copies in three brain regions (the hippocampus, cortex and cerebellum) of rats after irradiation their whole-head with 150 MeV protons at doses of 3 and 5 Gy. The study was performed in 2-months old male Spraque Dawley rats (n = 5 each group). The mtDNA copy numbers were determined by real-time PCR. The level of mtDNA heteroplasmy was estimated using Surveyor nuclease technology. Our results show that after head exposure to protons, levels of mtDNA copy number in three rat brain regions increase significantly as the levels of mtDNA mutant copies increase. The most significant elevation is observed in the hippocampus. In conclusion, an increase in mtDNA mutant copies may contribute to mitochondrial dysfunction accompanied by increased oxidative stress in different brain regions and promote the development of neurodegenerative diseases and the induction of carcinogenesis.


Assuntos
Encéfalo/efeitos da radiação , DNA Mitocondrial/efeitos da radiação , Terapia com Prótons/efeitos adversos , Animais , Encéfalo/metabolismo , Cerebelo/efeitos da radiação , Córtex Cerebral/efeitos da radiação , Variações do Número de Cópias de DNA/genética , Hipocampo/efeitos da radiação , Masculino , Mitocôndrias/genética , Mutação/genética , Mutação/efeitos da radiação , Prótons/efeitos adversos , Ratos
3.
Cerebellum ; 18(1): 22-32, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29725949

RESUMO

Spinocerebellar ataxia type 3 (SCA3) is a polyglutamine neurodegenerative disease resulting from the misfolding and accumulation of a pathogenic protein, causing cerebellar dysfunction, and this disease currently has no effective treatments. Far-infrared radiation (FIR) has been found to protect the viability of SCA3 cells by preventing mutant ataxin-3 protein aggregation and promoting autophagy. However, this possible treatment still lacks in vivo evidence. This study assessed the effect of FIR therapy on SCA3 in vivo by using a mouse model over 28 weeks. Control mice carried a healthy wild-type ATXN3 allele that had a polyglutamine tract with 15 CAG repeats (15Q), whereas SCA3 transgenic mice possessed an allele with a pathological polyglutamine tract with expanded 84 CAG (84Q) repeats. The results showed that the 84Q SCA3 mice displayed impaired motor coordination, balance abilities, and gait performance, along with the associated loss of Purkinje cells in the cerebellum, compared with the normal 15Q controls; nevertheless, FIR treatment was sufficient to prevent those defects. FIR significantly improved performance in terms of maximal contact area, stride length, and base support in the forepaws, hindpaws, or both. Moreover, FIR treatment supported the survival of Purkinje cells in the cerebellum and promoted the autophagy, as reflected by the induction of autophagic markers, LC3II and Beclin-1, concomitant with the reduction of p62 and ataxin-3 accumulation in cerebellar Purkinje cells, which might partially contribute to the rescue mechanism. In summary, our results reveal that FIR confers therapeutic effects in an SCA3 transgenic animal model and therefore has considerable potential for future clinical use.


Assuntos
Cerebelo/patologia , Raios Infravermelhos/uso terapêutico , Doença de Machado-Joseph/patologia , Doença de Machado-Joseph/radioterapia , Atividade Motora , Animais , Ataxina-3/genética , Ataxina-3/metabolismo , Autofagia/efeitos da radiação , Cerebelo/metabolismo , Cerebelo/efeitos da radiação , Modelos Animais de Doenças , Marcha/efeitos da radiação , Doença de Machado-Joseph/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora/efeitos da radiação , Equilíbrio Postural/efeitos da radiação , Distribuição Aleatória
4.
Hum Brain Mapp ; 38(9): 4563-4573, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28594097

RESUMO

Cervical dystonia (CD) is the most common type of focal dystonia, causing abnormal movements of the neck and head. In this study, we used noninvasive imaging to investigate the motor system of patients with CD and uncover the neural correlates of dystonic symptoms. Furthermore, we examined whether a commonly prescribed anticholinergic medication in CD has an effect on the dystonia-related brain abnormalities. Participants included 16 patients with CD and 16 healthy age-matched controls. We collected functional MRI scans during a force task previously shown to extensively engage the motor system, and diffusion and T1-weighted MRI scans from which we calculated free-water and brain tissue densities. The dystonia group was also scanned ca. 2 h after a 2-mg dose of trihexyphenidyl. Severity of dystonia was assessed pre- and post-drug using the Burke-Fahn-Marsden Dystonia Rating Scale. Motor-related activity in CD was altered relative to controls in the primary somatosensory cortex, cerebellum, dorsal premotor and posterior parietal cortices, and occipital cortex. Most importantly, a regression model showed that increased severity of symptoms was associated with decreased functional activity of the somatosensory cortex and increased activity of the cerebellum. Structural imaging measures did not differ between CD and controls. The single dose of trihexyphenidyl altered the fMRI signal in the somatosensory cortex but not in the cerebellum. Symptom severity was not significantly reduced post-treatment. Findings show widespread changes in functional brain activity in CD and most importantly that dystonic symptoms relate to disrupted activity in the somatosensory cortex and cerebellum. Hum Brain Mapp 38:4563-4573, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Cerebelo/efeitos da radiação , Atividade Motora/fisiologia , Córtex Sensório-Motor/fisiopatologia , Torcicolo/fisiopatologia , Antidiscinéticos/uso terapêutico , Toxinas Botulínicas/uso terapêutico , Mapeamento Encefálico , Cerebelo/diagnóstico por imagem , Cerebelo/efeitos dos fármacos , Cerebelo/fisiopatologia , Estudos de Coortes , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Atividade Motora/efeitos dos fármacos , Vias Neurais/diagnóstico por imagem , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiopatologia , Fármacos Neuromusculares/uso terapêutico , Córtex Sensório-Motor/diagnóstico por imagem , Córtex Sensório-Motor/efeitos dos fármacos , Índice de Gravidade de Doença , Torcicolo/diagnóstico por imagem , Torcicolo/tratamento farmacológico , Triexifenidil/uso terapêutico
5.
J Cell Mol Med ; 18(6): 1060-70, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24548607

RESUMO

Although melatonin (MT) has been reported to protect cells against oxidative damage induced by electromagnetic radiation, few reports have addressed whether there are other protective mechanisms. Here, we investigated the effects of MT on extremely low-frequency electromagnetic field (ELF-EMF)-induced Nav activity in rat cerebellar granule cells (GCs). Exposing cerebellar GCs to ELF-EMF for 60 min. significantly increased the Nav current (INa ) densities by 62.5%. MT (5 µM) inhibited the ELF-EMF-induced INa increase. This inhibitory effect of MT is mimicked by an MT2 receptor agonist and was eliminated by an MT2 receptor antagonist. The Nav channel steady-state activation curve was significantly shifted towards hyperpolarization by ELF-EMF stimulation but remained unchanged by MT in cerebellar GC that were either exposed or not exposed to ELF-EMF. ELF-EMF exposure significantly increased the intracellular levels of phosphorylated PKA in cerebellar GCs, and both MT and IIK-7 did not reduce the ELF-EMF-induced increase in phosphorylated PKA. The inhibitory effects of MT on ELF-EMF-induced Nav activity was greatly reduced by the calmodulin inhibitor KN93. Calcium imaging showed that MT did not increase the basal intracellular Ca(2+) level, but it significantly elevated the intracellular Ca(2+) level evoked by the high K(+) stimulation in cerebellar GC that were either exposed or not exposed to ELF-EMF. In the presence of ruthenium red, a ryanodine-sensitive receptor blocker, the MT-induced increase in intracellular calcium levels was reduced. Our data show for the first time that MT protects against neuronal INa that result from ELF-EMF exposure through Ca(2+) influx-induced Ca(2+) release.


Assuntos
Cálcio/metabolismo , Cerebelo/citologia , Grânulos Citoplasmáticos/metabolismo , Campos Eletromagnéticos/efeitos adversos , Melatonina/farmacologia , Substâncias Protetoras/farmacologia , Canais de Sódio Disparados por Voltagem/metabolismo , Animais , Antioxidantes/farmacologia , Células Cultivadas , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Cerebelo/efeitos da radiação , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/efeitos da radiação , Masculino , Camundongos , Oxirredução , Técnicas de Patch-Clamp , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação
6.
Stem Cells ; 31(11): 2506-16, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23897709

RESUMO

Neural stem cells are highly susceptible to radiogenic DNA damage, however, little is known about their mechanisms of DNA damage response (DDR) and the long-term consequences of genotoxic exposure. Patched1 heterozygous mice (Ptc1(+/-)) provide a powerful model of medulloblastoma (MB), a frequent pediatric tumor of the cerebellum. Irradiation of newborn Ptc1(+/-) mice dramatically increases the frequency and shortens the latency of MB. In this model, we investigated the mechanisms through which multipotent neural progenitors (NSCs) and fate-restricted progenitor cells (PCs) of the cerebellum respond to DNA damage induced by radiation, and the long-term developmental and oncogenic consequences. These responses were assessed in mice exposed to low (0.25 Gy) or high (3 Gy) radiation doses at embryonic day 13.5 (E13.5), when NSCs giving rise to the cerebellum are specified but the external granule layer (EGL) has not yet formed, or at E16.5, during the expansion of granule PCs to form the EGL. We found crucial differences in DDR and apoptosis between NSCs and fate-restricted PCs, including lack of p21 expression in NSCs. NSCs also appear to be resistant to oncogenesis from low-dose radiation exposure but more vulnerable at higher doses. In addition, the pathway to DNA repair and the pattern of oncogenic alterations were strongly dependent on age at exposure, highlighting a differentiation-stage specificity of DNA repair pathways in NSCs and PCs. These findings shed light on the mechanisms used by NSCs and PCs to maintain genome integrity during neurogenesis and may have important implications for radiation risk assessment and for development of targeted therapies against brain tumors.


Assuntos
Cerebelo/crescimento & desenvolvimento , Cerebelo/efeitos da radiação , Células-Tronco Neurais/efeitos da radiação , Células-Tronco/fisiologia , Células-Tronco/efeitos da radiação , Animais , Apoptose/efeitos da radiação , Diferenciação Celular/fisiologia , Diferenciação Celular/efeitos da radiação , Cerebelo/citologia , Cerebelo/patologia , Dano ao DNA , Reparo do DNA , Meduloblastoma/genética , Meduloblastoma/patologia , Meduloblastoma/radioterapia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Neurais/citologia , Células-Tronco Neurais/fisiologia , Células-Tronco/citologia
7.
Toxicol Mech Methods ; 24(5): 347-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24730455

RESUMO

Radio frequency wave (RFW) generated by base transceiver station has been reported to produce deleterious effects on the central nervous system function, possibly through oxidative stress. This study was conducted to evaluate the effect of RFW-induced oxidative stress in the cerebellum and encephalon and the prophylactic effect of vitamin C on theses tissues by measuring the antioxidant enzymes activity, including: glutathione peroxidase, superoxide dismutase, catalase, and malondialdehyde (MDA). Thirty-two adult male Sprague-Dawley rats were randomly divided into four equal groups. The control group; the control-vitamin C group received L-ascorbic acid (200 mg/kg of body weight/day by gavage) for 45 days. The RFW group was exposed to RFW and the RFW+ vitamin C group was exposed to RFW and received vitamin C. At the end of the experiment, all groups were killed and encephalon and cerebellum of all rats were removed and stored at -70 °C for measurement of antioxidant enzymes activity and MDA. The results indicate that exposure to RFW in the test group decreased antioxidant enzymes activity and increased MDA compared with the control groups (p < 0.05). The protective role of vitamin C in the treated group improved antioxidant enzymes activity and reduced MDA compared with the test group (p < 0.05). It can be concluded that RFW causes oxidative stress in the brain and vitamin C improves the antioxidant enzymes activity and decreases MDA.


Assuntos
Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Encéfalo/efeitos da radiação , Cerebelo/efeitos da radiação , Estresse Oxidativo/efeitos dos fármacos , Animais , Encéfalo/metabolismo , Catalase/metabolismo , Telefone Celular , Cerebelo/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos da radiação , Ondas de Rádio/efeitos adversos , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo
8.
Neuroimage ; 56(4): 2238-48, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21473922

RESUMO

Brain tumors are the leading cause of death and disability from childhood disease in developed countries. Pediatric posterior fossa tumors are often effectively controlled with a combination of surgery, radiation, and chemotherapy, depending on tumor type. White matter injury following resection of tumor and radiation treatment is associated with cognitive declines, including working memory deficits. We investigated how brain injury following treatment for posterior fossa tumors results in deficits in working memory. We used diffusion tensor imaging and probabilistic tractography to examine the structural integrity of cerebello-thalamo-cerebral tracts in patients and healthy children. We also compared working memory outcome in patients versus controls, and related this function to integrity of cerebello-thalamo-cerebral tracts. Bilateral cerebello-thalamo-cerebral tracts were delineated in all participants. Patients treated with a combination of surgery and radiation had lower mean anisotropy and higher mean radial diffusivity within the cerebellar regions of the cerebello-thalamo-cerebral tract compared to patients treated with surgery only and healthy controls. Poorer working memory scores were observed for the cranial radiation group relative to controls. Reduced anisotropy and higher radial diffusivity within the entire cerebello-thalamo-cerebral pathway predicted lower working memory. Our finding that working memory function is related to the integrity of cerebello-thalamo-cerebral connections is a novel contribution to the understanding of cerebral-cerebellar communication. Identifying differences in the structural integrity of white matter for specific pathways is an essential step in attempting to localize the effects of posterior fossa tumors and their treatment methods.


Assuntos
Cerebelo/patologia , Transtornos da Memória/etiologia , Vias Neurais/patologia , Procedimentos Neurocirúrgicos/efeitos adversos , Lesões por Radiação/patologia , Tálamo/patologia , Anisotropia , Cerebelo/efeitos dos fármacos , Cerebelo/efeitos da radiação , Criança , Terapia Combinada , Imagem de Tensor de Difusão , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Neoplasias Infratentoriais/radioterapia , Neoplasias Infratentoriais/cirurgia , Masculino , Transtornos da Memória/patologia , Memória de Curto Prazo/fisiologia , Vias Neurais/efeitos dos fármacos , Vias Neurais/efeitos da radiação , Radioterapia/efeitos adversos , Tálamo/anatomia & histologia , Tálamo/efeitos dos fármacos , Tálamo/efeitos da radiação
9.
Nat Methods ; 5(4): 331-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18311146

RESUMO

Light-activated ion channels provide a precise and noninvasive optical means for controlling action potential firing, but the genes encoding these channels must first be delivered and expressed in target cells. Here we describe a method for bestowing light sensitivity onto endogenous ion channels that does not rely on exogenous gene expression. The method uses a synthetic photoisomerizable small molecule, or photoswitchable affinity label (PAL), that specifically targets K+ channels. PALs contain a reactive electrophile, enabling covalent attachment of the photoswitch to naturally occurring nucleophiles in K+ channels. Ion flow through PAL-modified channels is turned on or off by photoisomerizing PAL with different wavelengths of light. We showed that PAL treatment confers light sensitivity onto endogenous K+ channels in isolated rat neurons and in intact neural structures from rat and leech, allowing rapid optical regulation of excitability without genetic modification.


Assuntos
Potenciais de Ação/efeitos da radiação , Ativação do Canal Iônico/efeitos da radiação , Neurônios , Canais de Potássio/metabolismo , Marcadores de Afinidade/química , Animais , Compostos Azo/química , Células Cultivadas , Cerebelo/citologia , Cerebelo/metabolismo , Cerebelo/efeitos da radiação , Hipocampo/citologia , Hipocampo/metabolismo , Hipocampo/efeitos da radiação , Sanguessugas , Neurônios/metabolismo , Neurônios/efeitos da radiação , Estimulação Luminosa , Fotoquímica , Compostos de Amônio Quaternário/química , Ratos
10.
Mutat Res ; 722(2): 114-8, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-20478395

RESUMO

Ionizing radiation is an important treatment modality, but it is also a well-known genotoxic agent capable of damaging cells and tissues. Therefore radiation treatment can cause numerous side effects in exposed tissues and organs. Radiotherapy is a part of the front-line treatment regime for brain cancer patients, but can cause severe functional and morphological changes in exposed brain tissues. However, the mechanisms of radiation-induced effects in the brain are not well understood and are under-investigated. Recent data has implicated short RNAs, especially microRNAs, as important in radiation responses, yet nothing is known about radiation-induced changes in the brain microRNAome. We analyzed the effects of X-ray irradiation on microRNA expression in the hippocampus, frontal cortex, and cerebellum of male and female mice. Here, we report tissue-, time-, and sex-specific brain radiation responses, as well as show evidence of an interplay between microRNAs and their targets. Specifically, we show that changes in the expression of the miR-29 family may be linked, at least in part, to altered expression of de novo methyltransferase DNMT3a and changed global DNA methylation levels. Further, these sex-specific epigenetic changes may be correlated to the prevalence of radiation-induced cancers in males. We identified several microRNAs that can potentially serve as biomarkers of brain radiation exposure. In summary, our study may provide an important roadmap for further analysis of microRNA expression in different brain regions of male and female mice and for detailed dissection of radiation-induced brain responses.


Assuntos
Cerebelo/efeitos da radiação , Lobo Frontal/efeitos da radiação , Hipocampo/efeitos da radiação , MicroRNAs/efeitos da radiação , Animais , Cerebelo/metabolismo , Dano ao DNA , Metilação de DNA , Feminino , Lobo Frontal/metabolismo , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Caracteres Sexuais , Raios X
11.
Eur Rev Med Pharmacol Sci ; 15(7): 729-42, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21780540

RESUMO

BACKGROUND AND OBJECTIVES: Mobile phone radiation and health concerns have been raised, especially following the enormous increase in the use of wireless mobile telephony throughout the world. The present study aims to investigate the effect of one hour daily exposure to electromagnetic radiation (EMR) with frequency of 900 Mz (SAR 1.165 w/kg, power density 0.02 mW/cm2) on the levels of amino acid neurotransmitters in the midbrain, cerebellum and medulla of adult and young male albino rats. MATERIALS AND METHODS: Adult and young rats were divided into two main groups (treated and control). The treated group of both adult and young rats was exposed to EMR for 1 hour daily. The other group of both adult and young animals was served as control. The determination of amino acid levels was carried out after 1 hour, 1 month, 2 months and 4 months of EMR exposure as well as after stopping radiation. RESULTS: Data of the present study showed a significant increase in both excitatory and inhibitory amino acids in the cerebellum of adult and young rats and midbrain of adult animals after 1 hour of EMR exposure. In the midbrain of adult animals, there was a significant increase in glycine level after 1 month followed by significant increase in GABA after 4 months. Young rats showed significant decreases in the midbrain excitatory amino acids. In the medulla, the equilibrium ratio percent (ER%) calculations showed a state of neurochemical inhibition after 4 months in case of adult animals, whereas in young animals, the neurochemical inhibitory state was observed after 1 month of exposure due to significant decrease in glutamate and aspartate levels. This state was converted to excitation after 4 months due to the increase in glutamate level. CONCLUSION: The present changes in amino acid concentrations may underlie the reported adverse effects of using mobile phones.


Assuntos
Aminoácidos/metabolismo , Encéfalo/efeitos da radiação , Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Fatores Etários , Envelhecimento , Animais , Encéfalo/metabolismo , Cerebelo/metabolismo , Cerebelo/efeitos da radiação , Masculino , Bulbo/metabolismo , Bulbo/efeitos da radiação , Mesencéfalo/metabolismo , Mesencéfalo/efeitos da radiação , Ratos , Medição de Risco , Fatores de Tempo
12.
Proc Natl Acad Sci U S A ; 105(34): 12445-50, 2008 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-18711141

RESUMO

The central dogma of radiation biology, that biological effects of ionizing radiation are a direct consequence of DNA damage occurring in irradiated cells, has been challenged by observations that genetic/epigenetic changes occur in unexposed "bystander cells" neighboring directly-hit cells, due to cell-to-cell communication or soluble factors released by irradiated cells. To date, the vast majority of these effects are described in cell-culture systems, while in vivo validation and assessment of biological consequences within an organism remain uncertain. Here, we describe the neonatal mouse cerebellum as an accurate in vivo model to detect, quantify, and mechanistically dissect radiation-bystander responses. DNA double-strand breaks and apoptotic cell death were induced in bystander cerebellum in vivo. Accompanying these genetic events, we report bystander-related tumor induction in cerebellum of radiosensitive Patched-1 (Ptch1) heterozygous mice after x-ray exposure of the remainder of the body. We further show that genetic damage is a critical component of in vivo oncogenic bystander responses, and provide evidence supporting the role of gap-junctional intercellular communication (GJIC) in transmission of bystander signals in the central nervous system (CNS). These results represent the first proof-of-principle that bystander effects are factual in vivo events with carcinogenic potential, and implicate the need for re-evaluation of approaches currently used to estimate radiation-associated health risks.


Assuntos
Efeito Espectador/efeitos da radiação , Cerebelo/efeitos da radiação , Neoplasias/etiologia , Receptores de Superfície Celular/genética , Animais , Animais Recém-Nascidos , Comunicação Celular , Cerebelo/patologia , Dano ao DNA , Junções Comunicantes , Genes Supressores de Tumor , Heterozigoto , Camundongos , Neoplasias/patologia , Receptores Patched , Receptor Patched-1 , Radiação Ionizante
13.
Electromagn Biol Med ; 30(4): 253-60, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22047463

RESUMO

During the last several decades, numerous studies have been performed aiming at the question of whether or not exposure to radiofrequency radiation (RFR) influences the permeability of the blood-brain barrier (BBB). The objective of this study was to investigate the effect of RFR on the permeability of BBB in male and female Wistar albino rats. Right brain, left brain, cerebellum, and total brain were analyzed separately in the study. Rats were exposed to 0.9 and 1.8 GHz continuous-wave (CW) RFR for 20 min (at SARs of 4.26 mW/kg and 1.46 mW/kg, respectively) while under anesthesia. Control rats were sham-exposed. Disruption of BBB integrity was detected spectrophotometrically using the Evans-blue dye, which has been used as a BBB tracer and is known to be bound to serum albumin. Right brain, left brain, cerebellum, and total brain were evaluated for BBB permeability. In female rats, no albumin extravasation was found in in the brain after RFR exposure. A significant increase in albumin was found in the brains of the RF-exposed male rats when compared to sham-exposed male brains. These results suggest that exposure to 0.9 and 1.8 GHz CW RFR at levels below the international limits can affect the vascular permeability in the brain of male rats. The possible risk of RFR exposure in humans is a major concern for the society. Thus, this topic should be investigated more thoroughly in the future.


Assuntos
Barreira Hematoencefálica/efeitos da radiação , Permeabilidade Capilar/efeitos da radiação , Cerebelo/efeitos da radiação , Ondas de Rádio , Animais , Barreira Hematoencefálica/metabolismo , Cerebelo/metabolismo , Azul Evans/metabolismo , Feminino , Masculino , Ratos , Ratos Wistar , Albumina Sérica/metabolismo , Espectrofotometria
14.
Int J Radiat Biol ; 97(3): 348-355, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33320758

RESUMO

PURPOSE: The present study aims to investigate the radioprotective effect of melatonin (MEL) against early period brain damage caused by different dose rate beams in the experimental rat model. MATERIALS AND METHODS: Forty-eight Sprague Dawley rats were randomly divided into six groups; the control, only melatonin, low dose rate-radiotherapy (LDR-RT), high dose rate-radiotherapy (HDR-RT) groups and (LDR-RT) + MEL and (HDR-RT) + MEL radiotherapy plus melatonin groups. Each rat administered melatonin was given a dose of 10 mg/kg through intraperitoneal injection, 15 minutes before radiation exposure. The head and neck region of each rat in only radiotherapy and radiotherapy plus melatonin groups was irradiated with a single dose of 16 Gy in LDR-RT and HDR-RT beams. Rats in all groups were examined for histopathology and biochemistry analysis 10 days after radiotherapy. RESULTS: Comparing the findings for LDR-RT and HDR-RT only radiotherapy groups and the control group, there was a statistically significant difference in histopathological and biochemical parameters, however, melatonin administered in radiotherapy plus melatonin groups contributed improving these parameters (p < .05). There was no statistically significant difference between LDR-RT and HDR-RT beams (p > .05). CONCLUSIONS: It was concluded that melatonin applied before LDR-RT and HDR-RT radiotherapy protected early period radiotherapy-induced brain damage. The effects of clinically low and high dose beams on the cerebral cortex and cerebellum were investigated histopathologically for the first time. HDR beams can be safely applied in brain radiotherapy. However, more experimental rat and clinical studies are needed to explain the radiobiological uncertainties about the clinic dose rate on different cancerous and healthy tissues.


Assuntos
Cerebelo/efeitos da radiação , Córtex Cerebral/efeitos da radiação , Melatonina/farmacologia , Protetores contra Radiação/farmacologia , Radioterapia/efeitos adversos , Animais , Cerebelo/patologia , Córtex Cerebral/patologia , Feminino , Dosagem Radioterapêutica , Ratos , Ratos Sprague-Dawley
15.
Sci Rep ; 11(1): 3070, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542291

RESUMO

Non-invasive brain stimulation techniques including repetitive transcranial magnetic stimulation (rTMS), continuous theta-burst stimulation (cTBS), paired associative stimulation (PAS), and transcranial direct current stimulation (tDCS) have been applied over the cerebellum to induce plasticity and gain insights into the interaction of the cerebellum with neo-cortical structures including the motor cortex. We compared the effects of 1 Hz rTMS, cTBS, PAS and tDCS given over the cerebellum on motor cortical excitability and interactions between the cerebellum and dorsal premotor cortex / primary motor cortex in two within subject designs in healthy controls. In experiment 1, rTMS, cTBS, PAS, and tDCS were applied over the cerebellum in 20 healthy subjects. In experiment 2, rTMS and PAS were compared to sham conditions in another group of 20 healthy subjects. In experiment 1, PAS reduced cortical excitability determined by motor evoked potentials (MEP) amplitudes, whereas rTMS increased motor thresholds and facilitated dorsal premotor-motor and cerebellum-motor cortex interactions. TDCS and cTBS had no significant effects. In experiment 2, MEP amplitudes increased after rTMS and motor thresholds following PAS. Analysis of all participants who received rTMS and PAS showed that MEP amplitudes were reduced after PAS and increased following rTMS. rTMS also caused facilitation of dorsal premotor-motor cortex and cerebellum-motor cortex interactions. In summary, cerebellar 1 Hz rTMS and PAS can effectively induce plasticity in cerebello-(premotor)-motor pathways provided larger samples are studied.


Assuntos
Potencial Evocado Motor/fisiologia , Córtex Motor/fisiologia , Estimulação Transcraniana por Corrente Contínua , Estimulação Magnética Transcraniana , Adulto , Cerebelo/diagnóstico por imagem , Cerebelo/fisiologia , Cerebelo/efeitos da radiação , Potencial Evocado Motor/efeitos da radiação , Feminino , Humanos , Masculino , Córtex Motor/diagnóstico por imagem , Córtex Motor/efeitos da radiação , Inibição Neural/efeitos da radiação , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiologia , Vias Neurais/efeitos da radiação
16.
Cerebellum ; 9(4): 548-55, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20665254

RESUMO

Saccadic eye movements are driven by motor commands that are continuously modified so that errors created by eye muscle fatigue, injury, or-in humans-wearing spectacles can be corrected. It is possible to rapidly adapt saccades in the laboratory by introducing a discrepancy between the intended and actual saccadic target. Neurophysiological and lesion studies in the non-human primate as well as neuroimaging and patient studies in humans have demonstrated that the oculomotor vermis (lobules VI and VII of the posterior cerebellum) is critical for saccadic adaptation. We studied the effect of transiently disrupting the function of posterior cerebellum with repetitive transcranial magnetic stimulation (rTMS) on the ability of healthy human subjects to adapt saccadic eye movements. rTMS significantly impaired the adaptation of the amplitude of saccades, without modulating saccadic amplitude or variability in baseline conditions. Moreover, increasing the intensity of rTMS produced a larger impairment in the ability to adapt saccadic size. These results provide direct evidence for the role of the posterior cerebellum in man and further evidence that TMS can modulate cerebellar function.


Assuntos
Adaptação Fisiológica/fisiologia , Cerebelo/efeitos da radiação , Transtornos da Motilidade Ocular/etiologia , Movimentos Sacádicos/efeitos da radiação , Estimulação Magnética Transcraniana/efeitos adversos , Adaptação Fisiológica/efeitos da radiação , Adulto , Cerebelo/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Movimentos Sacádicos/fisiologia
17.
Bioelectromagnetics ; 31(4): 270-6, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20041436

RESUMO

The effects of extremely low frequency magnetic fields (ELF-MF) on acetylcholinesterase (AChE) activity of synaptosomal membranes were investigated. Sinusoidal fields with 50 Hz frequency and different amplitudes caused AChE activity to decrease about 27% with a threshold of about 0.74 mT. The decrease in enzymatic activity was independent of the time of permanence in the field and was completely reversible. Identical results were obtained with exposure to static MF of the same amplitudes. Moreover, the inhibitory effects on enzymatic activity are spread over frequency windows with different maximal values at 60, 200, 350, and 475 Hz. When synaptosomal membranes were solubilized with Triton, ELF-MF did not affect AChE activity, suggesting the crucial role of the membrane, as well as the lipid linkage of the enzyme, in determining the conditions for inactivation. The results are discussed in order to give an interpretation at molecular level of the macroscopic effects produced by ELF-MF on biological systems, in particular the alterations of embryo development in many organisms due to acetylcholine accumulation.


Assuntos
Acetilcolinesterase/metabolismo , Cerebelo/enzimologia , Campos Eletromagnéticos , Sinaptossomos/enzimologia , Sinaptossomos/efeitos da radiação , Animais , Cerebelo/efeitos da radiação , Relação Dose-Resposta à Radiação , Camundongos
18.
Acta Neurochir Suppl ; 106: 171-5, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19812943

RESUMO

The objective of this study was to investigate the metabolic responses of normal appearing cerebellar tissue after posterior fossa tumor treatment, and to identify characteristics of the particular treatment method. Moreover, this work examined the metabolic alterations of normal appearing tissue induced by a particular tumor state including resection, stagnation, progression, and recurrence. The studied group consisted of 29 patients treated for posterior fossa tumors. All of them were irradiated with a total dose of 54 Gy at 1.8 Gy/fraction (median values). In addition, 13 underwent chemotherapy, 25 underwent total tumor resection, 18 were tumor-free in control examinations, 5 had a stable disease, and tumor progression or recurrence was observed in 2 and 4 cases, respectively. The 69 spectra, acquired using a MRI/MRS 2T system, were analyzed using Partial Least Squares Discriminant Analysis (PLS-DA) with orthogonal signal correction (OSC) spectral filtering. A significantly elevated spectral region (0.97-1.55 ppm) was observed in patients after total resection in comparison to non-operated subjects. Patients treated with chemotherapy showed an elevated band between 1.15-1.75 and 2.7-3.0 ppm and had decreases in the remaining parts of the spectra. Increases in lactate and decreases in the remaining metabolites were characteristic for the tumor progression/recurrence group. Pattern recognition methods coupled with MRS revealed significant treatment-dependent alterations in normal appearing cerebellar tissue, as well as metabolic changes induced by tumor progression/recurrence.


Assuntos
Cerebelo/patologia , Neoplasias Infratentoriais/patologia , Neoplasias Infratentoriais/fisiopatologia , Espectroscopia de Ressonância Magnética/métodos , Reconhecimento Fisiológico de Modelo/fisiologia , Adolescente , Cerebelo/fisiopatologia , Cerebelo/efeitos da radiação , Terapia Combinada , Elétrons , Feminino , Humanos , Neoplasias Infratentoriais/radioterapia , Imageamento por Ressonância Magnética/métodos , Masculino , Análise Multivariada , Testes Neuropsicológicos , Reconhecimento Fisiológico de Modelo/efeitos da radiação , Dosagem Radioterapêutica
19.
Brain Res ; 1744: 146919, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32485174

RESUMO

The adverse health consequences of exposure to electromagnetic field emitted from cell phone has recently raised public concerns worldwide. Also, the Global System for Mobile Communications (GSM) standard that operates in 900 MHz frequency is the most popular. Therefore, we aimed to investigate the adverse effect of exposure to 900 MHz EMF (1 h/day) on the cerebella of 12-week-old rats. We also evaluated the protective activity of luteolin (20 µg/kg/day) against possible biological change in the cerebellar tissues exposed to EMF. Twenty-four male wistar albino rats were randomly assigned into four group of six rats: Control, EMF, EMF + luteolin, luteolin. Serological and biochemical analyses, as well as histopathological examination were performed on all cerebellar samples. We found that SOD (superoxide dismutase) level was significantly increased in the EMF group compared to the control group (p < 0.05). To the contrary, decreased SOD activity was detected in the EMF + luteolin group compared to control group (p < 0.05). The total number of Purkinje and granular cells was significantly decreased in the EMF group compared to the control group (p < 0.05). In the EMF + luteolin group, the total number of Purkinje and granular cells was significantly higher than the EMF group (p < 0.05). Histopathological evaluation also showed destructive damage to the architectures of cerebellar tissues. Our results suggest that exposure to EMF may cause cellular damage to the rat cerebellum. Further, the improvement of cerebellar damage may have resulted from antioxidant efficacy of luteolin by alleviating oxidative stress.


Assuntos
Cerebelo/efeitos dos fármacos , Campos Eletromagnéticos/efeitos adversos , Radiação Eletromagnética , Luteolina/farmacologia , Fármacos Neuroprotetores/farmacologia , Animais , Cerebelo/patologia , Cerebelo/efeitos da radiação , Masculino , Ratos , Ratos Wistar , Superóxido Dismutase/efeitos da radiação
20.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(1): 77-81, 2020 Jan 28.
Artigo em Chinês | MEDLINE | ID: mdl-32476377

RESUMO

OBJECTIVE: To evaluate the effects of prenatal radiation of 850~1 900 MHz mobile phone on white matter in cerebellum of adult rat offspring. METHODS: Pregnant rats were randomly divided into short term maternal radiation group, long term maternal radiation group and control group. Rats in short term and long term maternal radiation group were exposed to 6 h/d and 24 h/d mobile phone radiation during 1-17 days of pregnancy, respectively. The cerebellums of offspring rats at the age of 3 month(n=8)were taken. Cell morphology in cerebellum was studied by hematoxylin-eosin (HE) staining. The expressions of myelin basic protein (MBP), neurofilament-L (NF-L) and glial fibrillary acidic protein (GFAP) in cerebellum of rat offspring were detected by immunohistochemistry and Western blot. RESULTS: Compared to control group, the morphological changes of purkinje cells in cerebellum were obvious in rat offspring of short term and long term maternal radiation group. Compared to control group, decreased MBP and NF-L expressions and increased GFAP expression were observed in long term maternal radiation group(all P<0.05). Compared to short term radiation group, the expressions of MBP and NF-L were down-regulated (all P<0.05) and the expression of GFAP was up- regulated(P<0.05) in long term radiation group. CONCLUSION: Prenatal mobile phone radiation might lead to the damage of myelin and axon with activity of astrocytes in cerebellum of male rat offspring, which is related to the extent of radiation.


Assuntos
Telefone Celular , Cerebelo/efeitos da radiação , Radiação Eletromagnética , Efeitos Tardios da Exposição Pré-Natal , Substância Branca/efeitos da radiação , Animais , Cerebelo/patologia , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Proteína Básica da Mielina/metabolismo , Proteínas de Neurofilamentos/metabolismo , Gravidez , Distribuição Aleatória , Ratos , Substância Branca/patologia
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