Apresentação

Universidade Federal de São Paulo (UNIFESP) Departamento de FisiologiaUNIFESP, Depto. de FisiologiaSciEL

Neo-Timm staining in the thalamus of chronically epileptic rats

The thalamus is an important modulator of seizures and is severely affected in cholinergic models of epilepsy. In the present study, chronically epileptic rats had their brains processed for neo-Timm and acetylcholinesterase two months after the induction of status epilepticus with pilocarpine. Both controls and pilocarpine-treated animals presented neo-Timm staining in the anterodorsal nucleus, laterodorsal nucleus, reticular nucleus, most intralaminar nuclei, nucleus reuniens, and rhomboid nucleus of the thalamus, as well as in the zona incerta. The intensity of neo-Timm staining was similar in control and pilocarpine-treated rats, except for the nucleus reuniens and the rhomboid nucleus, which had a lower intensity of staining in the epileptic group. In animal models of temporal lobe epilepsy, zinc seems to modulate glutamate release and to decrease seizure activity. In this context, a reduction of neo-Timm-stained terminals in the midline thalamus could ultimately result in an increased excitatory activity, not only within its related nuclei, but also in anatomical structures that receive their efferent connections. This might contribute to the pathological substrate observed in chronic pilocarpine-treated epileptic animals.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaUNIFESP, EPM, Depto. de FisiologiaSciEL

c-Fos expression induced by electroacupuncture at the Zusanli point in rats submitted to repeated immobilization

In laboratory animals, acupuncture needs to be performed on either anesthetized or, if unanesthetized, restrained subjects. Both procedures up-regulate c-Fos expression in several areas of the central nervous system, representing therefore a major pitfall for the assessment of c-Fos expression induced by electroacupuncture. Thus, in order to reduce the effect of acute restraint we used a protocol of repeated restraint for the assessment of the brain areas activated by electroacupuncture in adult male Wistar rats weighing 180-230 g. Repeated immobilization protocols (6 days, 1 h/day and 13 days, 2 h/day) were used to reduce the effect of acute immobilization stress on the c-Fos expression induced by electroacupuncture at the Zusanli point (EA36S). Animals submitted to immobilization alone or to electroacupuncture (100 Hz, 2-4 V, faradic wave) in a non-point region were compared to animals submitted to electroacupuncture at EA36S (4 animals/subgroup). c-Fos expression was measured in 41 brain areas by simple counting of cells and the results are reported as number of c-Fos-immunoreactive cells/10,000 µm². The protocols of repeated immobilization significantly reduced the immobilization-induced c-Fos expression in most of the brain areas analyzed (P < 0.05). Animals of the EA36S groups had significantly higher levels of c-Fos expression in the dorsal raphe nucleus, locus coeruleus, posterior hypothalamus and central medial nucleus of the thalamus. Furthermore, the repeated immobilization protocols intensified the differences between the effects of 36S and non-point stimulation in the dorsal raphe nucleus (P < 0.05). These data suggest that high levels of stress can interact with and mask the evaluation of specific effects of acupuncture in unanesthetized animals.Universidade Federal Rural do Rio de Janeiro Departamento de Ciências FisiológicasUniversidade de São Paulo Instituto de Ciências Biomédicas Departamento de Fisiologia e BiofísicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PsicobiologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaUNIFESP, EPM, Depto. de PsicobiologiaUNIFESP, EPM, Depto. de FisiologiaSciEL

Effect of the acupoints ST-36 (Zusanli) and SP-6 (Sanyinjiao) on intestinal myoelectric activity of Wistar rats

Despite its ancient use as a therapeutic tool to treat several ailments, acupuncture still faces the challenge of scrutiny by Western science both in terms of its efficacy and in terms of the characterization of its effects and mechanisms of actions underlying these effects. We investigated under well-controlled and carefully characterized conditions the influence of electrical stimulation of acupuncture points ST-36 (Zusanli) and SP-6 (Sanyinjiao) on the myoelectric activity of the small intestine of 38 adult male Wistar rats. Electrical recordings obtained by means of four electrodes chronically implanted in the small intestine were used to assess the effects of acupuncture (electroacupuncture stimulation set at 2 Hz, intermittent stimulation, 1 V, for 30 min). Immobilization of the animals was associated with a consistent decrease (-8 ± 7%) in the myoelectric activity of the small intestine as measured by means of the root mean square. Conversely, acupuncture was able to significantly increase (overshoot) this activity compared to baseline (+44 ± 7%). In contrast, immobilized animals subjected to sham acupuncture had only modest (nonsignificant) increases in myoelectric activity (+9 ± 6%). Using carefully controlled conditions we confirmed previous noncontrolled studies on the ability of acupuncture to alter intestinal motility. The characterization of the topographic and temporal profiles of the effects observed here represents a basis for future dissection of the physiological and pharmacological systems underlying these effects.Universidade Federal de São Paulo (UNIFESP) Departamento de Ortopedia e Traumatologia Divisão de Medicina Chinesa e AcupunturaUniversidade Federal de São Paulo (UNIFESP) Departamento de FisiologiaUNIFESP, Depto. de Ortopedia e Traumatologia Divisão de Medicina Chinesa e AcupunturaUNIFESP, Depto. de FisiologiaSciEL

Transplant of GABAergic Precursors Restores Hippocampal Inhibitory Function in a Mouse Model of Seizure Susceptibility

Defects in GABAergic function can cause epilepsy. in the last years, cell-based therapies have attempted to correct these defects with disparate success on animal models of epilepsy. Recently, we demonstrated that medial ganglionic eminence (MGE)-derived cells grafted into the neonatal normal brain migrate and differentiate into functional mature GABAergic interneurons. These cells are able to modulate the local level of GABA-mediated synaptic inhibition, which suggests their suitability for cell-based therapies. However, it is unclear whether they can integrate in the host circuitry and rescue the loss of inhibition in pathological conditions. Thus, as proof of principle, we grafted MGE-derived cells into a mouse model of seizure susceptibility caused by specific elimination of GABAergic interneuron subpopulations in the mouse hippocampus after injection of the neurotoxic saporin conjugated to substance P (SSP-Sap). This ablation was associated with significant decrease in inhibitory postsynaptic currents (IPSC) on CA1 pyramidal cells and increased seizure susceptibility induced by pentylenetetrazol (PTZ). Grafting of GFP(+) MGE-derived cells in SSP-Sap-treated mice repopulates the hippocampal ablated zone with cells expressing molecular markers of mature interneurons. Interestingly, IPSC kinetics on CA1 pyramidal cells of ablated hippocampus significantly increased after transplantation, reaching levels similar to the normal mice. More importantly, this was associated with reduction in seizure severity and decrease in postseizure mortality induced by PTZ. Our data show that MGE-derived cells fulfill most of the requirements for an appropriate cell-based therapy, and indicate their suitability for neurological conditions where a modulation of synaptic inhibition is needed, such as epilepsy.Spanish Ministry of Science and InnovationCIPFCarlos III Institute (Spanish Ministry of Science and Innovation)Generalitat ValencianaAndalusian Ctr Mol Biol & Regenerat Med CABIMER, Dept Cell Therapy & Regenerat Med, Seville, SpainCIPF, Valencia, SpainUniversidade Federal de São Paulo, Dept Physiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, São Paulo, BrazilSpanish Ministry of Science and Innovation: SAF 07/61880Spanish Ministry of Science and Innovation: FIS 07/0079Web of Scienc

The pattern of c-Fos expression and its refractory period in the brain of rats and monkeys

Intense activation of neurons triggers the appearance of immediate expression genes, including c-Fos. This gene is related to various signal cascades involved in biochemical processes such as neuronal plasticity, cell growth and mitosis. Here we investigate the expression pattern and the refractory period of c-Fos in rats and monkey's brains after stimulation with pentylenetetrazol. Rats and monkeys were sacrificed at various times after PTZ-induced seizure. Here we show that rats and monkeys already showed c-Fos expression at 0.5 h after seizure. Yet, the pattern of protein expression was longer in monkeys than rats, and also was not uniform (relative intensity) across different brain regions in monkeys as opposed to rats. in addition monkeys had a regional brain variation with regard to the temporal profile of c-Fos expression, which was not seen in rats. the refractory period after a second PTZ stimulation was also markedly different between rats and monkeys with the latter even showing a summatory effect on c-Fos expression after a second stimulation. However, assessment of c-Fos mRNA in rats indicated a post-transcriptional control mechanism underlying the duration of the refractory period. the difference in the protein expression pattern in rodents and primates characterizes a functional aspect of brain biochemistry that differs between these mammalian orders and may contribute for the more developed primate cognitive complexity as compared to rodents given c-Fos involvement in cognitive and learning tasks.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Physiol, BR-04039032 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Biochem, BR-04039032 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04039032 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Biochem, BR-04039032 São Paulo, SP, BrazilWeb of Scienc

Em uma encruzilhada: potencial do nível plasmático de lítio como preditor da dose ideal

OBJECTIVE: Lithium has been successfully employed to treat bipolar disorder for decades, and recently, was shown to attenuate the symptoms of other pathologies such as Alzheimer's disease, Down's syndrome, ischemic processes, and glutamate-mediated excitotoxicity. However, lithium's narrow therapeutic range limits its broader use. Therefore, the development of methods to better predict its dose becomes essential to an ideal therapy. METHOD: the performance of adult Wistar rats was evaluated at the open field and elevated plus maze after a six weeks treatment with chow supplemented with 0.255%, or 0.383% of lithium chloride, or normal feed. Thereafter, blood samples were collected to measure the serum lithium concentration. RESULTS: Animals fed with 0.255% lithium chloride supplemented chow presented a higher rearing frequency at the open field, and higher frequency of arms entrance at the elevated plus maze than animals fed with a 50% higher lithium dose presented. Nevertheless, both groups presented similar lithium plasmatic concentration. DISCUSSION: different behaviors induced by both lithium doses suggest that these animals had different lithium distribution in their brains that was not detected by lithium serum measurement. CONCLUSION: serum lithium concentration measurements do not seem to provide sufficient precision to support its use as predictive of behaviors.OBJETIVO: Além de ser usado há décadas para tratar distúrbio bipolar, o lítio, mais recentemente, demonstrou-se eficaz para Alzheimer, síndrome de Down, processos isquêmicos e excitotoxicidade mediada por glutamato. Contudo, a estreita janela terapêutica do lítio limita seu uso. Portanto, o estabelecimento de métodos preditivos de dose torna-se importante. MÉTODO: O desempenho de ratos Wistar adultos foi avaliado no campo aberto e labirinto em cruz elevado após seis semanas de tratamento com uma ração suplementada com 0,255% ou 0,383% de cloreto de lítio ou ração normal. Coletou-se amostras de sangue para dosagem plasmática do lítio. RESULTADOS: Os animais alimentados com a ração com 0,255% de cloreto de lítio fizeram mais rearing no campo aberto e tiveram uma maior freqüência de entradas nos braços do labirinto elevado que os animais que ingeriram a dose mais alta. Apesar disso, verificou-se níveis plasmáticos de lítio semelhantes em ambos os grupos. DISCUSSÃO: A variação nos comportamentos destarte a presença de níveis plasmáticos semelhantes sugere que as diferentes doses produziram diferentes concentrações cerebrais não detectadas pela medida plasmática. CONCLUSÃO: Medidas da concentração plasmática de lítio não permitem prever de forma completa seus efeitos comportamentais.Universidade Federal de São Paulo (UNIFESP) Department of PhysiologyUNIFESP, Department of PhysiologySciEL

Intervenções mente-corpo para o tratamento de insônia: uma revisão

OBJECTIVE: As insomnia is highly prevalent, and side effects of medication are well-known, mind-body interventions are increasingly being sought. The objective of this study is to present a narrative review regarding the effects of mind-body interventions for the treatment of insomnia. METHOD: A PubMed search was conducted including only randomized, controlled trials in which the main objective was to treat insomnia. DISCUSSION: Twelve studies were selected. In three of the studies, objective parameters (polysomnography) were analyzed. Mind-body interventions were able to improve sleep efficiency and total sleep time. Most can ameliorate sleep quality; some can reduce the use of hypnotic drugs in those who are dependent on these drugs. CONCLUSION: According to the studies we selected, self-reported sleep was improved by all mind-body treatments, among them yoga, relaxation, Tai Chi Chih and music. Cognitive behavioral therapy seems to be the most effective mind-body intervention. Cognitive behavioral therapy was the only intervention that showed better results than medication. However, considering that only five of the twelve studies chosen reached a score of 3 in the Jadad scale, new studies with a higher methodological quality have to be conducted especially in mind-body interventions that belong to the complementary or alternative medicine field.OBJETIVO: Considerando-se que a insônia é altamente prevalente, e os efeitos colaterais das medicações para seu tratamento são bem conhecidos, pesquisas no campo das intervenções mente-corpo têm sido desenvolvidas. O objetivo deste estudo é apresentar uma revisão narrativa sobre os efeitos das intervenções mente-corpo para o tratamento de insônia. MÉTODO: Uma busca pelo site Pubmed foi conduzida incluindo-se apenas estudos controlados e randomizados nos quais o principal objetivo era o tratamento da insônia. DISCUSSÃO: Doze estudos foram selecionados. Em três deles, parâmetros objetivos (polissonografia) foram analisados. Vários destes estudos mostraram melhora na qualidade do sono; em grupos de usuários de drogas hipnóticas ocorreu redução no uso das mesmas. CONCLUSÃO: De acordo com os estudos selecionados, todas as intervenções mente-corpo melhoraram ao menos a qualidade subjetiva do sono, dentre elas yoga, Tai Chi Chih e música. A terapia comportamental cognitiva parece ser a mais efetiva destas intervenções e foi a única que mostrou melhores resultados que a medicação. Porém, considerando que apenas cinco dos 12 estudos selecionados alcançaram o escore 3 na escala de Jadad, novos estudos com melhor qualidade metodológica precisam ser conduzidos especialmente dentre as intervenções mente-corpo que estão no campo das práticas complementares ou alternativas.Universidade Federal de São Paulo (UNIFESP) Department of PsychobiologyUniversidade Nove de Julho Núcleo de Estudos em Saúde Coletiva e da FamíliaInstituto Israelita de Ensino e Pesquisa Albert Einstein Instituto do CérebroUniversidade Federal de São Paulo (UNIFESP) Instituto do SonoUniversidade Federal de São Paulo (UNIFESP) Department of GynecologyUniversidade Federal de São Paulo (UNIFESP) Centro Cochrane do BrasilUniversidade Federal de São Paulo (UNIFESP) Department of PhysiologyUNIFESP, Department of PsychobiologyUNIFESP, Instituto do SonoUNIFESP, Department of GynecologyUNIFESP, Centro Cochrane do BrasilUNIFESP, Department of PhysiologySciEL