Efeitos da exposição à nicotina e à fumaça de cigarro durante a lactação sobre o sistema de recompensa cerebral em ratos

Crianças de mães fumantes são mais suscetíveis a se tornarem adultos obesos e se viciarem em drogas ou alimentos palatáveis. Drogas e alimentos ativam a via mesolímbica de recompensa, causando sensação de prazer que induz ainda mais o consumo. Assim, avaliamos a relação entre a exposição apenas à nicotina ou à fumaça do cigarro durante a lactação com a preferência alimentar e sistema dopaminérgico de recompensa cerebral das proles, em dois modelos de programação: Modelo I: no 2o dia pós-natal (PN), lactantes receberam implante de minibombas osmóticas que liberam nicotina (NIC) ou salina (C), durante 14 dias. Em PN150 e novamente em PN160, as proles foram divididas em 4 grupos para um desafio alimentar: N-SC e C-SC que receberam ração padrão; N-SSD e C-SSD que podiam escolher livremente entre as dietas hiperlipídica e hiperglicídica. A ingestão alimentar foi avaliada após 12 h. As mães foram sacrificadas apenas na 21 da lactação (desmame) e as proles em PN15 (com nicotina), PN21 e PN170 (ausência da NIC). Ao desmame, as ratas lactantes NIC apresentaram menor conteúdo de tirosina hidroxilase (TH), maior OBRb e SOCS3 na area tegmentar ventral (VTA); menor TH, maior receptor de dopamina 1 (D1R), receptor de dopamina 2 (D2R) e transportador de dopamina (DAT) no núcleo accumbens (NAc); maior conteúdo de TH no estriado dorsal (DS); e maior D2R e SOCS3 no núcleo arqueado (ARC). Em PN15, os filhotes NIC apresentaram maior conteúdo de D1R, D2R e menor DAT no NAc, enquanto em PN21, apresentaram apenas menor DAT no DS, e menor conteúdo de pSTAT3 em ARC. Aos 170 dias, as proles SSD demonstraram maior preferência para a ração hiperlipídica. No entanto, os animais N-SSD consumiram mais ração hiperglicidica do que as proles C-SSD. A prole N apresentou menor conteúdo de D2R e DAT no NAc e menor D2R no ARC. Modelo II: as mães e suas proles foram divididas em: expostos à fumaça do cigarro (grupo S: 4 vezes / dia, do 3 ao 21 dia de lactação), e expostos ao ar filtrado (grupo C). Em PN175, as proles foram divididas em 4 grupos para o desafio alimentar S-SC, C-SC, S-SSD e C-SSD. A ingestão alimentar foi avaliada após 30 min e 12 h. Em PN180, as proles foram sacrificadas. O grupo S-SSD ingeriu mais das rações palatáveis do que o grupo C-SSD em 30 min e 12 h. Ambos os grupos preferiram a ração hiperlipídica. No entanto, os animais S-SSD consumiram mais ração hiperlipídica do que C-SSD em 30 min. A prole S apresentou menor conteúdo de TH no VTA, menor conteúdo de TH, D2R e maior conteúdo de D1R no NAc e menor OBRb no ARC. Demonstramos que tanto a nicotina isolada como a exposição à fumaça do cigarro durante a lactação resultaram em mudanças no sistema dopaminérgico das proles, programando o comportamento alimentar devido à diminuição da dopamina no NAc.

The computer simulation of primate (Macaca mulatta) spatial visual delayed response and cerebral prefrontal control function

Cerebral prefrontal function is one of the important aspects in neurobiology. Based on the experimental results of neuroanatomy, neurophysiology, behavioral sciences, and the principles of cybernetics and information theory after constructed a simple model simulating prefrontal control function, this paper simulated the behavior of Macaca mulatta completing delayed tasks both before and after its cerebral prefrontal cortex being damaged. The results indicated that there is an obvious difference in the capacity of completing delayed response tasks for the normal monkeys and those of prefrontal cortex cut away. The results are agreement with experiments. The authors suggest that the factors of affecting complete delayed response tasks might be in information keeping and extracting of memory including information storing, keeping and extracting procedures rather than in information storing process.

Neurons characterization in the cerebral ganglia of the green-lipped mussel, Perna canaliculus, using antibodies raised against neuropeptides and neurotransmitters involved in gastropod egg-laying behaviour and bivalve reproduction and spawning

Immunohistochemical techniques were used to characterise central neurons in the cerebral ganglia of both male and female Perna canaliculus. We used mollusc antibodies raised against neuropeptides and neurotransmitters known to control reproduction and spawning. Anti-ELH and anti-APGWamide showed very strong immunoreactivity in small type of neurons. Anti-5-HT and anti-DA immunoreactivity was mostly in large type of neurons. The labelled neurons are consistent with descriptions of neurosecretory cells implicated in the control of reproduction and spawning on the basis of earlier histological staining techniques used in this species. The use of selective immunological markers for peptides and amines appears to be a promising tool for further characterisation of neurosecretory cells, and to isolate and characterise neuropeptides and other biologically active materials involved in the control of reproduction in Perna canaliculus.

Effect of Pyrethrins and Rosemary on the ATPase Activities of Rat Cerebral Synaptosome

除虫菊酯越来越广泛地被应用于农业和家庭昆虫防治,主要通过作用于膜结合蛋白而对动物起神经毒性.迷迭香因其抗氧化功能而被应用于很多商业化的除虫菊酯产品中.本实验以大鼠大脑突触体ATP酶为研究对象,对除虫菊酯和迷迭香的药理学进行了研究.用Percoll梯度离心法分离突触体,通过检测无机磷的量来测定总ATP酶和Mg2+-ATP酶活性.结果表明,除虫菊酯在浓度为10 μmol/L时总ATP酶和Mg2+-ATP酶分别降低到对照的80.3%和46.9%.迷迭香在浓度为0.3～30 μmol/L时几乎不影响ATP酶活性,当浓度上升到3 000 μmol/L时,总ATP酶活性降低到66.8%,而Mg2+-ATP酶活性降低到54.5%. 10 μmol/L 除虫菊酯和30 μmol/L迷迭香混合物引起总ATP酶和Mg2+-ATP酶分别降低到72.9%和33.4%.结论: 1) 除虫菊酯能抑制大鼠大脑ATP酶活性; 2) 迷迭香只在高浓度下才对ATP酶有抑制作用; 3) 迷迭香能增强除虫菊酯对ATP酶的抑制作用.图3参19

GABAA receptor chloride channels are involved in the neuroprotective role of GABA following oxygen and glucose deprivation in the rat cerebral cortex but not in the hippocampus.

Assays on "ex vivo" sections of rat hippocampus and rat cerebral cortex, subjected to oxygen and glucose deprivation (OGD) and a three-hour reperfusion-like (RL) recovery, were performed in the presence of either GABA or the GABA(A) receptor binding site antagonist, bicuculline. Lactate dehydrogenase (LDH) and propidium iodide were used to quantify cell mortality. We also measured, using real-time quantitative polymerase chain reaction (qPCR), the early transcriptional response of a number of genes of the glutamatergic and GABAergic systems. Specifically, glial pre- and post-synaptic glutamatergic transporters (namely GLAST1a, EAAC-1, GLT-1 and VGLUT1), three GABAA receptor subunits (α1, β2 and γ2), and the GABAergic presynaptic marker, glutamic acid decarboxylase (GAD65), were studied. Mortality assays revealed that GABAA receptor chloride channels play an important role in the neuroprotective effect of GABA in the cerebral cortex, but have a much smaller effect in the hippocampus. We also found that GABA reverses the OGD-dependent decrease in GABA(A) receptor transcript levels, as well as mRNA levels of the membrane and vesicular glutamate transporter genes. Based on the markers used, we conclude that OGD results in differential responses in the GABAergic presynaptic and postsynaptic systems.

The effect of concentration and duration of normobaric oxygen in reducing caspase-3 and -9 expression in a rat-model of focal cerebral ischaemia.

The aim of this study was to determine the effect of different concentrations of normobaric oxygen (NBO) on neurological function and the expression of caspase-3 and -9 in a rat model of acute cerebral ischaemia. Sprague-Dawley rats (n=120) were randomly divided into four groups (n=30 per group), including 3 groups given NBO at concentrations of 33%, 45% or 61% and one control group given air (21% oxygen). After 2 h of ischaemic occlusion, each group was further subdivided into six subgroups (n=5) during reperfusion according to the duration (3, 6, 12, 24, 48 or 72 h) and concentration of NBO (33%, 45% or 61%) or air treatment. The Fluorescence Quantitative polymerase chain reaction (PCR) and immunohistochemistry were used to detect caspase-3 and -9 mRNA and protein relative expression respectively. The Neurologic Impairment Score (NIS) was significantly lower in rats given 61% NBO ≥3 h after reperfusion when compared to the control group (P<0.05, Mann–Whitney U). NBO significantly reduced caspase-3 and -9 mRNA and protein expression when compared to the control group at all NBO concentrations and time points (P<0.05, ANOVA). The expression of caspase-3 and -9 was lower in the group given 61% NBO compared any other group, and this difference was statistically significant when compared to the group given 33% NBO for ≥48 h and the control group (both P<0.05, ANOVA). These findings indicate that NBO may inhibit the apoptotic pathway by reducing caspase-3 and -9 expression, thereby promoting neurological functional recovery after stroke.

Revascularização pulpar

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

Estimulação cognitiva em idosos institucionalizados após Acidente Vascular Cerebral

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para a obtenção do grau de Mestre em Psicologia, ramo de Psicologia Clínica e da Saúde

How Does the Cerebral Cortex Work? Developement, Learning, Attention, and 3D Vision by Laminar Circuits of Visual Cortex

A key goal of behavioral and cognitive neuroscience is to link brain mechanisms to behavioral functions. The present article describes recent progress towards explaining how the visual cortex sees. Visual cortex, like many parts of perceptual and cognitive neocortex, is organized into six main layers of cells, as well as characteristic sub-lamina. Here it is proposed how these layered circuits help to realize the processes of developement, learning, perceptual grouping, attention, and 3D vision through a combination of bottom-up, horizontal, and top-down interactions. A key theme is that the mechanisms which enable developement and learning to occur in a stable way imply properties of adult behavior. These results thus begin to unify three fields: infant cortical developement, adult cortical neurophysiology and anatomy, and adult visual perception. The identified cortical mechanisms promise to generalize to explain how other perceptual and cognitive processes work.

Laminar Cortical Dynamics of Cognitive and Motor Working Memory, Sequence Learning and Performance: Toward a Unified Theory of How the Cerebral Cortex Works

How do the layered circuits of prefrontal and motor cortex carry out working memory storage, sequence learning, and voluntary sequential item selection and performance? A neural model called LIST PARSE is presented to explain and quantitatively simulate cognitive data about both immediate serial recall and free recall, including bowing of the serial position performance curves, error-type distributions, temporal limitations upon recall, and list length effects. The model also qualitatively explains cognitive effects related to attentional modulation, temporal grouping, variable presentation rates, phonemic similarity, presentation of non-words, word frequency/item familiarity and list strength, distracters and modality effects. In addition, the model quantitatively simulates neurophysiological data from the macaque prefrontal cortex obtained during sequential sensory-motor imitation and planned performance. The article further develops a theory concerning how the cerebral cortex works by showing how variations of the laminar circuits that have previously clarified how the visual cortex sees can also support cognitive processing of sequentially organized behaviors.

Use of physiotherapy and alternatives by children with cerebral palsy: a population study

Objectives: To describe the use of physiotherapy services and alternative therapies by a population of children with moderate to severe cerebral palsy (CP).
Design: Descriptive cross-sectional survey.
Subjects: A total of 212 parents of children aged 4–14 years with moderate to severe CP were identified from the Northern Ireland Cerebral Palsy Register (NICPR) and a random subsample of their paediatric physiotherapists.
Main measures: A standardized description of motor impairment or assessment form; a postal questionnaire to parents and paediatric physiotherapists (to validate parents’ reports of service use).
Response rates: In total, 85% of parent questionnaires were returned and 100% of paediatric physiotherapists responded.
Results: Service use among families was high; on average the families had contact with approximately seven services in a 6-month time interval. The overwhelming majority of children (96%) received physiotherapy during the school term and most (59%) received treatment at least twice a week for 30 min; 43% of children had their physiotherapy discontinued over the summer holidays. Over one-quarter (28%) of families had opted out of the NHS and bought alternatives like conductive education (21%) or private forms of conventional physiotherapy (16%). Children with more severe forms of CP, in special education, particularly at schools for physical disability, were high-intensity users of the physiotherapy service. Despite this, 74% of parents wanted more physiotherapy for their child.
Conclusions and implications: The demand for physiotherapy services is likely to continue given the relatively stable prevalence rate of CP, the proportion of children with disabling CP and the level of parent interest in the service. A number of quality aspects and gaps in the service have been identified.

Making doors open: caring for families of children with severe cerebral palsy

Cerebral palsy is a relatively rare condition affecting approximately 2-2.5 children in every 1,000 (Parkes et al 2001). It is a leading cause of physical disability in childhood and is often associated with severe motor and other impairments (Table 1). Improved survival of small and premature babies who are particularly at risk of developing the condition raises concerns about increasing numbers of children with cerebral palsy possibly with more severe forms. In the UK, information about the number and needs of children with CP is not collected routinely. The most reliable sources of information on CP in the UK comes from five dedicated case registers which have monitored live births in their respective geographically defined areas since the 1960s and 1970s. These registers have formed a collaborative network called the United Kingdom Collaboration of Cerebral Palsy Registers (or UKCP) and are listed in Table 2. All five registers are currently funded and all are active in surveillance activities and research.