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1.
FASEB J ; 35(5): e21400, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33793981

RESUMO

Anterior pituitary endocrine cells that release hormones such as growth hormone and prolactin are excitable and fire action potentials. In these cells, several studies previously showed that extracellular sodium (Na+ ) removal resulted in a negative shift of the resting membrane potential (RMP) and a subsequent inhibition of the spontaneous firing of action potentials, suggesting the contribution of a Na+ background conductance. Here, we show that the Na+ leak channel NALCN conducts a Ca2+ - Gd3+ -sensitive and TTX-resistant Na+ background conductance in the GH3 cell line, a cell model of pituitary endocrine cells. NALCN knockdown hyperpolarized the RMP, altered GH3 cell electrical properties and inhibited prolactin secretion. Conversely, the overexpression of NALCN depolarized the RMP, also reshaping the electrical properties of GH3 cells. Overall, our results indicate that NALCN is functional in GH3 cells and involved in endocrine cell excitability as well as in hormone secretion. Indeed, the GH3 cell line suitably models native pituitary cells that display a similar Na+ background conductance and appears as a proper cellular model to study the role of NALCN in cellular excitability.


Assuntos
Potenciais de Ação , Células Endócrinas/fisiologia , Canais Iônicos/metabolismo , Potenciais da Membrana , Proteínas de Membrana/metabolismo , Hipófise/fisiologia , Sódio/metabolismo , Animais , Células Endócrinas/citologia , Hipófise/citologia , Ratos
2.
Pharm Biol ; 59(1): 367-374, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33789075

RESUMO

CONTEXT: ECa 233 is the standardized extract of Centella asiatica (L.) Urban. (Apiaceae). It contains at least 85% of triterpenoid glycosides and yields neuroprotective and memory-enhancing effects. However, the exact molecules exerting the effects might be triterpenic acid metabolites reproduced through gut metabolism after orally ingesting C. asiatica, not triterpenoid glycosides. OBJECTIVE: This study demonstrates the effect of unmetabolized ECa 233 on hippocampal synaptic plasticity after directly perfusing ECa 233 over acute brain slices. MATERIALS AND METHODS: The brain slices obtained from 7-week-old male Wistar rats were randomly divided into 4 groups. We perfused either artificial cerebrospinal fluid (ACSF), 0.01% DMSO, 10 µg/mL ECa 233, or 100 µg/mL on brain slices, and measured the long-term potentiation (LTP) magnitude to determine the synaptic plasticity of hippocampal circuits in each group. RESULTS: The LTP magnitude of ACSF, DMSO, 10 ug/mL ECa 233, and 100 ug/mL ECa 233 groups increased from 100% to 181.26 ± 38.19%, 148.74 ± 5.40%, 273.71 ± 56.66%, 182.17 ± 18.61%, respectively. ECa 233 at the concentration of 10 µg/mL robustly and significantly enhanced hippocampal LTP magnitude. The data indicates an improvement of the hippocampal synaptic plasticity. DISCUSSION AND CONCLUSIONS: This study emphasizes the effectiveness of triterpenoid glycosides in ECa 233 on synaptic plasticity enhancement. Therefore, this study supported and complimented the known effects of C. asiatica extract on the enhancement of synaptic plasticity, and subsequently, learning and memory, suggesting that ECa 233 could be a promising memory enhancing agent.


Assuntos
Hipocampo/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Relação Dose-Resposta a Droga , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Hipocampo/metabolismo , Masculino , Memória/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Ratos , Ratos Wistar , Triterpenos/isolamento & purificação , Triterpenos/farmacologia
3.
Exp Brain Res ; 238(9): 1827-1837, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32500298

RESUMO

Individuals with Parkinson's disease (PD) have deficits in reach-to-grasp (RTG) execution and visuospatial processing which may be a result of dopamine deficiency in two brain regions: primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC). We hypothesized that improvement following M1 stimulation would be the result of a direct impact on motor execution; whereas, DLPFC stimulation would improve the role of DLPFC in visuospatial processing. The aim of pilot study was to investigate the effects of HF-rTMS on RTG performance by stimulating either M1 or DLPFC. Thirty individuals with PD participated (H&Y stages I-III). All of them were more affected on the right side. Participants were allocated into three groups. The DLPFC group received HF-rTMS over left DLPFC; while, the M1 group received HF-rTMS over left M1 of extensor digitorum communis representational area. The control group received HF-rTMS over the vertex. Before and immediately post HF-rTMS, right-hand RTG performance was measured under no barrier and barrier conditions. Additionally, TMS measures including motor-evoked-potential (MEP) amplitude and cortical silent period (CSP) were determined to verify the effects of HF-rTMS. For the results, there were no significant differences among the three groups. However, only the M1 group showed a significant decrease in movement time immediately after HF-rTMS for a barrier condition. Moreover, the M1 group showed a near-significant increase in hand opening and transport velocity. As for the DLPFC group, there was a near-significant increase in temporal transport-grasp coordination and a significant increase in velocity. Increased MEP amplitudes and a significantly longer CSP in the M1 and DLPFC groups confirmed the effects of HF-rTMS. Regarding non-significant results among the three groups, it is still inconclusive whether there were different effects of the rTMS on the two stimulation areas. This is a preliminary study demonstrating that HF-rTMS to M1 may improve RTG execution; whereas, HF-rTMS to DLPFC may improve visuospatial processing demands of RTG.


Assuntos
Córtex Motor , Doença de Parkinson , Mãos , Humanos , Doença de Parkinson/terapia , Projetos Piloto , Córtex Pré-Frontal , Estimulação Magnética Transcraniana
4.
Proc Natl Acad Sci U S A ; 109(41): 16726-30, 2012 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-22988089

RESUMO

Climbing fiber input to the cerebellum is believed to serve as a teaching signal during associative, cerebellum-dependent forms of motor learning. However, it is not understood how this neural pathway coordinates changes in cerebellar circuitry during learning. Here, we use pharmacological manipulations to prolong the postcomplex spike pause, a component of the climbing fiber signal in Purkinje neurons, and show that these manipulations enhance the rate of learning in classical eyelid conditioning. Our findings elucidate an unappreciated aspect of the climbing fiber teaching signal, and are consistent with a model in which convergent postcomplex spike pauses drive learning-related plasticity in the deep cerebellar nucleus. They also suggest a physiological mechanism that could modulate motor learning rates.


Assuntos
Piscadela/fisiologia , Condicionamento Palpebral/fisiologia , Fibras Nervosas/fisiologia , Células de Purkinje/fisiologia , Análise de Variância , Animais , Benzimidazóis/farmacologia , Piscadela/efeitos dos fármacos , Agonistas dos Canais de Cálcio/farmacologia , Fármacos Cardiovasculares/farmacologia , Núcleos Cerebelares/efeitos dos fármacos , Núcleos Cerebelares/fisiologia , Cerebelo/citologia , Cerebelo/efeitos dos fármacos , Cerebelo/fisiologia , Estimulação Elétrica , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Antagonistas GABAérgicos/farmacologia , Aprendizagem/efeitos dos fármacos , Aprendizagem/fisiologia , Camundongos , Picrotoxina/farmacologia , Células de Purkinje/efeitos dos fármacos , Pirimidinas/farmacologia , Quinoxalinas/farmacologia , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
5.
J Med Assoc Thai ; 97 Suppl 7: S45-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25141526

RESUMO

OBJECTIVE: The present study investigated the immediate effects of low frequency repetitive transcranial magnetic stimulation (LF-rTMS) combined with reach-to-grasp (RTG) training of the paretic hand in individuals with chronic stroke. MATERIAL AND METHOD: Fourteen participants were randomly assigned to receive LF-rTMS or sham stimulation conditions. All participants underwent RTG training after the stimulation. Corticospinal excitability (CE) of the non-lesioned hemisphere, the total time of the wolf motor function test (WMFT) for dexterity tasks, maximum aperture, and movement time of RTG actions were evaluated at baseline, after the stimulation, and after RTG training. RESULTS: Significant differences between interaction (group x time) were found in the total time of WMFT The CE of non-lesioned hemisphere diminished after LF-rTMS and showed moderate correlation with the reduction in time of RTG actions after the stimulation. The total time of WMFT and RTG actions reduced after motor training only in the LF-rTMS group. No change was observed in maximum aperture in either group. CONCLUSION: The application of LF-rTMS combined with RTG training enhanced the training effect as evidenced by faster movement for the dexterity tasks of the paretic hand than RTG training alone. The findings suggested the benefit of LF-rTMS for enhancing the training effects in stroke rehabilitation.


Assuntos
Força da Mão/fisiologia , Reabilitação do Acidente Vascular Cerebral , Estimulação Magnética Transcraniana/métodos , Idoso , Doença Crônica , Mãos/fisiopatologia , Humanos , Pessoa de Meia-Idade
6.
Heliyon ; 10(7): e28027, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38560220

RESUMO

Chronic cerebral ischemia hypoperfusion plays a role in the initiation and progression of vascular dementia, which causes changes in metabolites. Currently, there is no standard treatment to treat, prevent and reduce the severity of this condition. Thai herbal Yahom no.20 (YHF20) is indicated for fatigue and dizziness. The components of YHF20 have been found to have pharmacological effects related to the pathology of chronic cerebral ischemia hypoperfusion. This study aimed to investigate metabolomic changes after YHF20 administration in a rat model of permanent bilateral common carotid artery occlusion (2-VO) induced chronic cerebral ischemia hypoperfusion, and to explore its impact on spatial learning and memory. Albino Wistar rats were randomly allocated to 5 groups; sham, 2-VO, 2-VO+ 100 mg/kg YHF20, 2-VO+300 mg/kg YHF20, and 2-VO+1000 mg/kg YHF20. The rats were administered YHF20 daily by oral gavage for 56 days after 2-VO induction. Plasma was collected weekly for metabolome change analysis using LC-MS/QTof and toxicity study. The rats were evaluated for spatial learning and memory using the Morris water maze. The results showed that 78 known metabolites and 10 tentative pathways altered after chronic cerebral hypoperfusion, although it was not able to determine the effect on memory and learning behaviors of rats. Glutathione and glutathione metabolism might be metabolite-pathway that were the affect after YHF20 administration in cerebral ischemic condition. The 4 known metabolites may be the metabolites from the constituents of YHF20 could be considered and confirmed for quality control purpose. In conclusion, YHF20 administration might contribute to metabolic changes related to cerebral ischemia condition without the effect on spatial learning and memory, including hepatotoxicity and nephrotoxicity after 56 days of treatment. Alterations in the potential metabolites may provide data support for elucidating dementia pathogenesis and selecting pathways for intervention.

7.
Am J Chin Med ; 51(2): 329-353, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36695831

RESUMO

ECa 233 is a standardized extract of Centella asiatica (CA), an herb widely used in traditional Chinese and Ayurvedic medicine. Previous studies reported that ECa 233 enhanced memory retention and synaptic plasticity in the hippocampus of healthy rats. Because of this, we became curious whether ECa 233 has a therapeutic effect on the fear memory deficit in the triple transgenic Alzheimer's disease (3xTg-AD) model mice. Fear memory is a crucial emotional memory for survival that is found to be impaired in patients with early-onset Alzheimer's disease (AD). In this study, we orally administered ECa 233 (doses: 10, 30, and 100[Formula: see text]mg/kg) to 3xTg-AD mice, who were five months old, for 30 consecutive days. We found that ECa 233 prevented a cued fear memory deficit and enhanced hippocampal long-term potentiation (LTP) in 3xTg-AD mice. Subsequent proteomic and western blot analyses revealed increased expression levels of the molecules related to LTP induction and maintenance, including brain-derived neurotrophic factor (BDNF), tyrosine receptor kinase B (TrkB) and its network proteins, and extracellular signal-regulated kinase 1 and 2 (ERK1 and 2) in the hippocampi and amygdala of 3xTg-AD mice after ECa 233 pre-treatment. Our results indicate that ECa 233 is a promising potential herbal standardized extract that could be used in preventing the fear memory deficit and synaptic dysfunction before the early onset of AD.


Assuntos
Doença de Alzheimer , Centella , Camundongos , Ratos , Animais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Proteômica , Camundongos Transgênicos , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Medo , Hipocampo , Modelos Animais de Doenças
8.
Sci Rep ; 13(1): 6642, 2023 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-37095163

RESUMO

Chronic inflammatory temporomandibular disorder (TMD) pain has a high prevalence, and available nonspecific treatments have adverse side effects. ECa 233, a standardized Centella asiatica extract, is highly anti-inflammatory and safe. We investigated its therapeutic effects by injecting complete Freund's adjuvant (CFA) into right temporomandibular joint of mice and administering either ibuprofen or ECa 233 (30, 100, and 300 mg/kg) for 28 days. Inflammatory and nociceptive markers, bone density, and pain hypersensitivity were examined. CFA decreased ipsilateral bone density, suggesting inflammation localization, which ipsilaterally caused immediate calcitonin gene-related peptide elevation in the trigeminal ganglia (TG) and trigeminal subnucleus caudalis (TNC), followed by late increase of NaV1.7 in TG and of p-CREB and activation of microglia in TNC. Contralaterally, only p-CREB and activated microglia in TNC showed delayed increase. Pain hypersensitivity, which developed early ipsilaterally, but late contralaterally, was reduced by ibuprofen and ECa 233 (30 or 100 mg/kg). However, ibuprofen and only 100-mg/kg ECa 233 effectively mitigated marker elevation. This suggests 30-mg/kg ECa 233 was antinociceptive, whereas 100-mg/kg ECa 233 was both anti-inflammatory and antinociceptive. ECa 233 may be alternatively and safely used for treating chronic inflammatory TMD pain, showing an inverted U-shaped dose-response relationship with maximal effect at 100 mg/kg.


Assuntos
Centella , Hipersensibilidade , Transtornos da Articulação Temporomandibular , Animais , Masculino , Ibuprofeno , Dor , Adjuvante de Freund , Modelos Animais de Doenças , Analgésicos
9.
Top Stroke Rehabil ; 29(4): 241-254, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34320899

RESUMO

BACKGROUND: Task-oriented training with upper extremity (UE) skilled movements has been established as a method to regain function post stroke. Although improved UE function has been shown after this type of therapy, there is minimal evidence that brain plasticity is associated with this training. The accelerated skill acquisition program (ASAP) is an example of an approach for promoting UE function using targeting movements. OBJECTIVE: To investigate the effects of a single 2-hour session of ASAP in individuals with stroke on measures of brain plasticity as represented by corticospinal excitability (CE) and determine associations with reach-to-grasp (RTG) performance. METHODS: Eighteen post-acute stroke patients were randomized to two groups. Experimental group (n = 9) underwent ASAP for 2 hours, while the control group (n = 9) received dose equivalent usual and customary care. Both groups were evaluated for CE and RTG performance prior to the session and then four times after training: immediately, 1 day, 6 days, and 12 days. RESULTS: Significant alterations in CE were found in the peak-to-peak of Motor Evoked Potential amplitude of elbow and wrist extensor muscles in the lesioned hemisphere. The experimental group also demonstrated improved execution (shortened total movement time, TMT), feed-forward mechanism (deceleration time, DT) and planning (lengthened relative time to maximum hand aperture, RTApmax) compared to the control group. CONCLUSION: Alterations in brain plasticity occur concurrently with improvements in RTG performance in post-acute stroke patients with mild impairment after a single 2-hour session of task-oriented training and persist for at least 12 days.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Potencial Evocado Motor , Mãos , Humanos , Plasticidade Neuronal , Acidente Vascular Cerebral/complicações , Estimulação Magnética Transcraniana/métodos , Extremidade Superior
10.
J Appl Oral Sci ; 29: e20200575, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33503223

RESUMO

OBJECTIVE: Mirror-image pain is a kind of pain that occurs on the contralateral side, but its pathogenesis remains unclear. To develop an osteoarthritis mouse model for investigating mirror-image pain through observing nocifensive behaviors, histological changes, and nociceptive activity at days 3, 7, 14, 21, and 28 after the chemical induction of unilateral temporomandibular joint (TMJ) osteoarthritis. METHODOLOGY: We randomly divided 6-week-old mice into sham and complete Freund adjuvant groups. To induce nocifensive behaviors, we applied 0.04 g of von Frey filament, 10 psi of air puff, and cold acetone on both sides of whisker pads at different days. The histology of TMJ on both sides was observed by hematoxylin/eosin staining and microcomputed tomography scanning. Furthermore, the nociceptive activity was evaluated using the phosphorylated cyclic AMP response element binding protein (pCREB) and a microglia marker at different days in the trigeminal subnucleus caudalis. RESULTS: Nocifensive behaviors against mechanical and temperature stimuli on the contralateral side became stronger than the baseline on day 28, in agreement with the elevation of the pCREB and the microglia marker in the trigeminal subnucleus caudalis. Thus, hypernociception on the contralateral side occurred at day 28. CONCLUSIONS: Clearly, the TMJ model with unilateral osteoarthritis exhibited mirror-image pain. Therefore, this model is useful in investigating the pathogenesis of pain and in developing treatments.


Assuntos
Osteoartrite , Articulação Temporomandibular , Animais , Adjuvante de Freund , Camundongos , Osteoartrite/diagnóstico por imagem , Dor , Microtomografia por Raio-X
11.
J Appl Oral Sci ; 29: e20210329, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34705985

RESUMO

OBJECTIVES: To investigate the effect of a standardized extract of Centella asiatica (ECa 233), which has anti-inflammatory properties, on the local expression of the transient receptor potential vanilloid 1 (TRPV1), the acid-sensing ion channel subunit 3 (ASIC3), and the calcitonin gene-related peptide (CGRP) in the temporomandibular joint (TMJ) structure 21 days after injecting the TMJ with complete Freund's adjuvant (CFA). METHODOLOGY: A mouse model was induced by analyzing the CFA-injected TMJ on days 7, 14, and 21. We assessed TMJ histology by the osteoarthritis cartilage grade score. Then, we observed the effect of different ECa 233 concentrations (30, 100, and 300 mg/kg) and of 140 mg/kg ibuprofen doses on TRPV1, ASIC3, and CGRP local expression on day 21. RESULTS: Osteoarthritis cartilage scores were 1.17±0.37 and 3.83±0.68 on days 14 and 21, respectively, in the CFA group (n=5). On day 21, TRPV1, ASIC3, and CGRP expression significantly increased in the CFA group. In the ibuprofen-treated group, TRPV1 expression significantly decreased, but ASIC3 and CGRP showed no significant difference. All ECa 233 doses reduced TRPV1 expression, but the 100 mg/kg ECa 233 dose significantly decreased ASIC3 expression. CONCLUSIONS: TRPV1, ASIC3, and CGRP expression increased in mice with TMJ-OA on day 21. All ECa 233 and ibuprofen doses inhibited pathogenesis by modulating the local expression of TRPV1 and ASIC3. Therefore, ECa 233 was more effective than ibuprofen.


Assuntos
Centella , Osteoartrite , Animais , Mediadores da Inflamação , Camundongos , Osteoartrite/tratamento farmacológico , Extratos Vegetais/farmacologia , Articulação Temporomandibular
12.
Brain Res ; 1762: 147437, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33753066

RESUMO

The triple transgenic Alzheimer's disease (3xTg-AD) strain is a common mouse model used for studying the pathology and mechanism of Alzheimer's disease (AD). The 3xTg-AD strain exhibits two hallmarks of AD, amyloid beta (Aß) and neurofibrillary tangles. Several studies using different gender and age of 3xTg-AD mice to investigate their behavior phenotypes under the influence of various treatments have reported mixed results. Therefore, a comprehensive investigation on the optimal gender, age, and training paradigms used for behavioral studies of 3xTg-AD is necessary. In the present study, we investigated the behavioral phenotypes for the two genders of 3xTg-AD mice at 3, 6, 9, and 12 months old and compared the results with age-, gender-matched C57BL/6N control strain. All mice were subjected to tail flick, pinprick, open field, elevated plus maze, passive avoidance, and trace fear conditioning (TFC) tests to evaluate their sensory, locomotor, anxiety, and learning/memory functions. The results showed that TFC on male 3xTg-AD mice is optimal for studying the memory performance in AD. The sensory and locomotor functions of 3xTg-AD mice for two genders appear to be normal before 6 months, decline in fear memory afterwards. The differences between control and 3xTg-AD male mice in contextual and cued memory are robust, thus they are ideal for evaluating the effect of a treatment. Since it is costly and time consuming to obtain wildtype littermates as controls, C57BL/6N strain is suggested to be used as control mice because their baseline performance of sensorimotor functions are similar to that of 3xTg-AD mice.


Assuntos
Doença de Alzheimer/genética , Aprendizagem da Esquiva/fisiologia , Medo/fisiologia , Aprendizagem em Labirinto/fisiologia , Fenótipo , Caracteres Sexuais , Fatores Etários , Doença de Alzheimer/psicologia , Animais , Medo/psicologia , Feminino , Locomoção/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
13.
Mol Brain ; 14(1): 42, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33632301

RESUMO

Fear dysregulation is one of the symptoms found in post-traumatic stress disorder (PTSD) patients. The functional abnormality of the hippocampus is known to be implicated in the development of such pathology. Peroxiredoxin 6 (PRDX6) belongs to the peroxiredoxin family. This antioxidant enzyme is expressed throughout the brain, including the hippocampus. Recent evidence reveals that PRDX6 plays an important role in redox regulation and the modulation of several signaling molecules involved in fear regulation. Thus, we hypothesized that PRDX6 plays a role in the regulation of fear memory. We subjected a systemic Prdx6 knockout (Prdx6-/-) mice to trace fear conditioning and observed enhanced fear response after training. Intraventricular injection of lentivirus-carried mouse Prdx6 into the 3rd ventricle reduced the enhanced fear response in these knockout mice. Proteomic analysis followed by validation of western blot analysis revealed that several proteins in the MAPK pathway, such as NTRK2, AKT, and phospho-ERK1/2, cPLA2 were significantly upregulated in the hippocampus of Prdx6-/- mice during the retrieval stage of contextual fear memory. The distribution of PRDX6 found in the astrocytes was also observed throughout the hippocampus. This study identifies PRDX6 as a participant in the regulation of fear response. It suggests that PRDX6 and related molecules may have important implications for understanding fear-dysregulation associated disorders like PTSD.


Assuntos
Medo/fisiologia , Sistema de Sinalização das MAP Quinases , Memória/fisiologia , Peroxirredoxina VI/deficiência , Animais , Ansiedade/fisiopatologia , Astrócitos/metabolismo , Comportamento Animal , Biomarcadores/metabolismo , Ativação Enzimática , Comportamento Exploratório , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/metabolismo , Injeções Intraventriculares , Lentivirus/metabolismo , Locomoção , Rememoração Mental , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peroxirredoxina VI/metabolismo , Proteômica
14.
Behav Neurosci ; 123(1): 54-61, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19170430

RESUMO

In previous studies the cerebellar interpositus (IP) nucleus, but not the hippocampus, was shown to be necessary both for initial learning and retention and for long-term retention of the standard delay eyeblink conditioned response (CR). However, in the trace eyeblink CR procedure, the hippocampus is also necessary for initial learning and retention, but not for long-term retention. Here the authors evaluate the role of the IP nucleus in both initial learning and retention, and in long-term retention of the trace eyeblink CR, using muscimol infusion to reversibly inactivate the IP nucleus. For the short-term study, there were two subgroups, the first sequentially passed through acquisition, inactivation, and reacquisition phases, whereas the second subgroup went through inactivation, acquisition, and inactivation phases. For the long-term study, the rabbits acquired the CR and then rested for a month. Next, they were distributed into two subgroups: with or without retention training, and finally went through inactivation and reacquisition phases. The results showed that the prelearning IP nucleus inactivation prevented the acquisition of the trace CR, whereas the postlearning inactivation reversibly abolished the expression of both the short- and long-term CR.


Assuntos
Piscadela/fisiologia , Núcleos Cerebelares/fisiologia , Memória/classificação , Memória/fisiologia , Animais , Piscadela/efeitos dos fármacos , Mapeamento Encefálico , Núcleos Cerebelares/efeitos dos fármacos , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Clássico/fisiologia , Agonistas GABAérgicos/farmacologia , Masculino , Memória/efeitos dos fármacos , Muscimol/farmacologia , Membrana Nictitante/efeitos dos fármacos , Membrana Nictitante/fisiologia , Coelhos , Fatores de Tempo
15.
Sci Rep ; 9(1): 8404, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182820

RESUMO

The herb Centella asiatica has long been considered a memory tonic. A recent review found no strong evidence for improvement of cognitive function, suggesting negative results were due to limitations in dose, standardization and product variation. We used a standardized extract of C. asiatica (ECa 233) to study behavioral, cellular and molecular effects on learning and memory enhancement. ECa 233 (10, 30, and 100 mg/kg) was given orally to normal rats twice a day for 30 days. We used the Morris water maze to test spatial learning and performed acute brain slice recording to measure changes of synaptic plasticity in the hippocampus, a core brain region for memory formation. Plasticity-related protein expressions (NR2A, NR2B, PSD-95, BDNF and TrkB) in hippocampus was also measured. Rats receiving 10 and 30 mg/kg doses showed significantly enhanced memory retention, and hippocampal long-term potentiation; however, only the 30 mg/kg dose showed increased plasticity-related proteins. There was an inverted U-shaped response of ECa 233 on memory enhancement; 30 mg/kg maximally enhanced memory retention with an increase of synaptic plasticity and plasticity-related proteins in hippocampus. Our data clearly support the beneficial effect on memory retention of a standardized extract of Centella asiatica within a specific therapeutic range.


Assuntos
Centella/química , Memória/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Proteína 4 Homóloga a Disks-Large , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Plasticidade Neuronal/efeitos dos fármacos , Ratos Wistar , Receptor trkB/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Aprendizagem Espacial/efeitos dos fármacos , Memória Espacial/efeitos dos fármacos , Triterpenos/sangue
16.
Ann Rehabil Med ; 42(6): 777-787, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30613070

RESUMO

OBJECTIVE: To examine the long-term effects of the low-frequency repetitive transcranial magnetic stimulation (LFrTMS) combined with task-specific training on paretic hand function following subacute stroke. METHODS: Sixteen participants were randomly selected and grouped into two: the experimental group (real LFrTMS) and the control group (sham LF-rTMS). All the 16 participants were then taken through a 1-hour taskspecific training of the paretic hand. The corticospinal excitability (motor evoke potential [MEP] amplitude) of the non-lesioned hemisphere, and the paretic hand performance (Wolf Motor Function Test total movement time [WMFT-TMT]) were evaluated at baseline, after the LF-rTMS, immediately after task-specific training, 1 and 2 weeks after the training. RESULTS: Groups comparisons showed a significant difference in the MEP after LF-rTMS and after the training. Compared to the baseline, the MEP of the experimental group significantly decreased after LF-rTMS and after the training and that effect was maintained for 2 weeks. Group comparisons showed significant difference in WMFT-TMT after the training. Only in the experimental group, the WMFT-TMT of the can lifting item significantly reduced compared to the baseline and the effect was sustained for 2 weeks. CONCLUSION: The results of this study established that the improvement in paretic hand after task-specific training was enhanced by LF-rTMS and it persisted for at least 2 weeks.

18.
Neuroreport ; 28(16): 1031-1035, 2017 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-28885486

RESUMO

Bacopa monnieri has been used in Ayurvedic medicine as a memory enhancer for a long time; however, its direct effect on synaptic plasticity has not been investigated. To the best of our knowledge, this study is the first to report the effect of B. monnieri on long-term synaptic potentiation in acute hippocampal slices. Adult male Wistar rats were orally administered either sterile water or the ethanolic extract of B. monnieri for 60 days. The extracellular recording was performed to measure the field excitatory postsynaptic potential in the acute hippocampal slices of these rats. Our results showed that B. monnieri extract significantly increased long-term potentiation magnitude compared with the control group, whereas there was no change in basal synaptic transmission. The data support the beneficial mnemonic effect of B. monnieri, and suggest that this effect might be because of the increase of learning-associated synaptic machinery, resulting in the long-term potentiation enhancement and strengthening of hippocampal synapses, which plays a critical role in learning and memory formation.


Assuntos
Bacopa , Hipocampo/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Nootrópicos/farmacologia , Extratos Vegetais/farmacologia , Animais , Região CA1 Hipocampal/efeitos dos fármacos , Masculino , Nootrópicos/administração & dosagem , Extratos Vegetais/administração & dosagem , Ratos , Ratos Wistar , Transmissão Sináptica/efeitos dos fármacos
19.
PLoS One ; 12(1): e0170360, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28107420

RESUMO

Alzheimer's disease is characterized by the deposition of insoluble amyloid-ß peptides produced from the ß-amyloid precursor protein (ßAPP). Because α-secretase cleavage by ADAM10 and ADAM17 takes place in the middle of Aß, its activation is considered as a promising anti-AD therapeutic track. Here we establish that the polyherbal Wattana formula (WNF) stimulates sAPPα production in cells of neuronal and non-neuronal origins through an increase of both ADAM10 and ADAM17 catalytic activities with no modification of BACE1 activity and expression. This effect is blocked by specific inhibition or genetic depletion of these disintegrins and we show that WNF up-regulates ADAM10 transcription and ADAM17 maturation. In addition, WNF reduces Aß40 and Aß42 generation in human cell lines. Altogether, WNF presents all the characteristics of a potent preventive anti-Alzheimer formula. Importantly, this natural recipe, currently prescribed to patients for the treatment of other symptoms without any secondary effect, can be tested immediately for further clinical studies.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Medicina Herbária , Animais , Linhagem Celular , Ativação Enzimática , Humanos
20.
J. appl. oral sci ; 29: e20210329, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1346398

RESUMO

Abstract Objectives To investigate the effect of a standardized extract of Centella asiatica (ECa 233), which has anti-inflammatory properties, on the local expression of the transient receptor potential vanilloid 1 (TRPV1), the acid-sensing ion channel subunit 3 (ASIC3), and the calcitonin gene-related peptide (CGRP) in the temporomandibular joint (TMJ) structure 21 days after injecting the TMJ with complete Freund's adjuvant (CFA). Methodology A mouse model was induced by analyzing the CFA-injected TMJ on days 7, 14, and 21. We assessed TMJ histology by the osteoarthritis cartilage grade score. Then, we observed the effect of different ECa 233 concentrations (30, 100, and 300 mg/kg) and of 140 mg/kg ibuprofen doses on TRPV1, ASIC3, and CGRP local expression on day 21. Results Osteoarthritis cartilage scores were 1.17±0.37 and 3.83±0.68 on days 14 and 21, respectively, in the CFA group (n=5). On day 21, TRPV1, ASIC3, and CGRP expression significantly increased in the CFA group. In the ibuprofen-treated group, TRPV1 expression significantly decreased, but ASIC3 and CGRP showed no significant difference. All ECa 233 doses reduced TRPV1 expression, but the 100 mg/kg ECa 233 dose significantly decreased ASIC3 expression. Conclusions TRPV1, ASIC3, and CGRP expression increased in mice with TMJ-OA on day 21. All ECa 233 and ibuprofen doses inhibited pathogenesis by modulating the local expression of TRPV1 and ASIC3. Therefore, ECa 233 was more effective than ibuprofen.


Assuntos
Animais , Coelhos , Osteoartrite/tratamento farmacológico , Centella , Articulação Temporomandibular , Extratos Vegetais/farmacologia , Mediadores da Inflamação
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