Diss. Linköping : Univ., 2003. / Härtill 4 uppsatser.

Tem sido sugerido que combinar o treinamento de força (TF) com o treinamento com vibração (TV) pode ser mais vantajoso do que realizar o TF isolado. OBJETIVOS: Foi objetivo deste estudo avaliar os efeitos da combinação do TF com o TV (TF+V) sobre o desenvolvimento de hipertrofia e os desempenhos da força máxima dinâmica de membros inferiores (FMD) e do salto vertical (SV). Investigou-se também se os benefícios proporcionados pelo treinamento são acompanhados por alterações agudas e crônicas na excitabilidade das vias reflexas. METÓDOS: Foram realizados dois experimentos. No primeiro, foram avaliados os efeitos de uma sessão de treinamento sobre o desempenho do SV e excitabilidade das vias reflexas. Doze sujeitos do sexo masculino foram submetidos a quatro condições experimentais. Na condição TF, realizaram cinco séries de 10 repetições do exercício agachamento, com 90% da massa corporal. Nas condições TF+V30 e TF+V50, o TF foi realizado sobre a plataforma vibratória nas freqüências de 30 Hz (2-4 mm) e 50 Hz (4-6 mm), respectivamente. Na condição controle (C), os sujeitos permaneceram em repouso. Antes e depois de todas as condições experimentais, foram mensurados o desempenho do SV, e os reflexos de Hoffmann (H com amplitude de 20% da onda M máxima, H20%) e tendíneo máximo (Tmáx), no músculo sóleo. No segundo experimento, 29 sujeitos do sexo masculino foram divididos aleatoriamente nos grupos TF, TF+V30 e TF+V50. Os três grupos realizaram entre 3-5 séries de 6-12 RM do exercício agachamento, duas vezes por semana, durante dez semanas. Os grupos TF+V30 e TF+V50 fizeram o agachamento sobre a plataforma vibratória nas freqüências de 30 Hz (amplitude de 2-4 mm) e 50 Hz (amplitude de 4-6 mm), respectivamente. Antes e depois do período de treinamento, foram avaliados a área de secção transversa do quadríceps femoral (ASTQ), os desempenhos da FMD e do SV, os reflexos H e T máximos (Hmáx e Tmáx) e a onda M máxima (Mmáx), no músculo sóleo. RESULTADOS: No primeiro experimento, não foram verificadas alterações significantes na amplitude de H20% em nenhuma das condições (p>0,05). Houve diminuições significantes na amplitude das ondas Tmáx, nas condições TF (-7,4%) e TF+V50 (-11,1%), no primeiro minuto, em comparação ao período antes da intervenção (p<0,001). Foram verificadas diminuições significantes na altura do SV após a realização de todas as condições (C= -11,8%, TF= -6,6%, TF+V30= -7,7% e TF+V50= -7,4%) (p<0, 001). Não houve diferenças significantes entre grupos em nenhuma das variáveis (p>0,05). No segundo experimento, após as dez semanas de treinamento, foram verificados aumentos significantes na ASTQ (TF= 9,8%, TF+V30= 11,7%, TF+V50= 12,9%); na FMD (TF= 16,9%, TF+V30= 15,2%, TF+V50= 16,6%) e na altura do SV (TF= 6,0%, TF+V30= 7,2%, TF+V50= 6,0%) para os três grupos (p<0,05). Não houve diferença significante entre grupos em nenhuma das três variáveis. O período de treinamento não causou alterações significantes nas razões Hmáx/Mmáx (TF = +28%, TF+V30 = -16,3%, TF+V50 = -14%) e Tmáx/Mmáx (TF = -30,3%, TF+V30 = -38,2%, TF+V50 = -28,1%) (p>0,05). Contudo, foi verificado efeito principal de tempo significante para a razão Tmáx/Mmáx (-48,9%) (p<0,05). CONCLUSÕES: A realização de uma sessão de treinamento de força causa uma breve redução da atividade dos fusos musculares. Essa redução não é ampliada quando o TF é combinado com vibração. Realizar um período de TF sobre a plataforma de vibração não proporciona qualquer aumento adicional na ASTQ ou nos desempenhos da FMD e do SV, em relação ao que pode ser conseguido através do TF / It has been suggested that the combination of strength and vibration training may be advantageous when compared with strength training alone. OBJECTIVES: The aim of this study was to assess the effects of combined strength training and vibration (ST+V) on lower limb hypertrophy and on maximal dynamic strength (MDS) and vertical jump (VJ) performances. In addition, we investigate if the training-induced adaptations were in agreement to acute and chronic changes on spinal reflex excitability. METHODS: Two experiments were performed. In the first experiment, the effects of a single training session on VJ performance and spinal reflexes excitability were assessed. Twelve young male undertook four experimental conditions. On ST condition, subjects performed five sets with 10 repetitions on squat exercise with load of 90% body mass. On both ST+V30 and ST+V50 conditions, subjects performed the ST on a vibration platform at 30 Hz (2-4 mm) and 50 Hz (4-6 mm), respectively. In C condition, subjects were only assessed. Vertical jumping performance and Hoffman (at 20% of maximal M wave, H20%) and maximal tendon soleus reflexes (Tmáx) were measured before and after all experimental conditions. In the second experiment, twenty nine young male were randomized into three groups. All groups performed 3-5 sets with 6-12 RM on squat exercise, twice a week, for ten weeks. The ST+V30 and ST+V50 groups performed the squat exercise on the vibration platform at 30 Hz (2-4 mm) and 50 Hz (4-6 mm), respectively. Quadriceps cross sectional area (QCSA), MDS and VJ performances, maximal soleus H- and T- reflexes and maximal M wave (Mmáx) were assessed before and after the 10-week training period. RESULTS: in the first experiment, no significant changes were found in H20% amplitude in any experimental condition (p>0,05). Significant decrease on Tmáx amplitude was found after ST+V30 (-7.4%) and ST+V50 (-11.1%) conditions, after the first minute, compared to before intervention assessment. VJ decreased in all experimental conditions (C= -11.8%, ST= -6.6%, ST+V30= -7.7% and ST+V50= -7.4%) (p<0.001). There were no significant changes between groups in any variable measured (p>0.05). In the second experiment, significant increases were found in QCSA (ST= 9.8%, ST+V30= 11.7%, ST+V50= 12.9%); MDS (ST= 16.9%, ST+V30= 15.2%, ST+V50= 16.6%) and VJ height (ST= 6.0%, ST+V30= 7.2%, ST+V50= 6.0%) in all groups (p<0.05). There were no significant changes between groups in any variable measured (p>0.05). The training period did not induce significant changes in Hmáx/ Mmáx (ST = +28%, ST+V30 = -16,3%, ST+V50 = -14%) and Tmáx/ Mmáx ratios (ST = -30,3%, ST+V30 = -38,2%, ST+V50 = -28,1%) (p>0.05). However it was found a significant time effect for Tmáx/ Mmáx ratio (-48.9%) (p<0,05).CONCLUSION: A single strength training session induces a brief impairment on muscle spindle activity. This impairment is not greater if ST is combined with vibration. Performing ST on a vibration platform did not additionally increase QCSA, MDS and VJ performance compared with ST alone

The first two chapters are devoted to general issues relating to the Achilles tendon and brings important insights that are required for subsequent practical part. To the practical part is also devoted the following chapter. The first chapter is more of a medical nature. It explains the function and location of the Achilles tendon. Above all, the nature of the examination. Then follow chapters dealing with the assembly of functional devices for sensing the Achilles tendon reflex. This section begins in the third chapter discusses the preparation and block diagrams for the sensor and its technical solutions. The following chapter is about constructing electrical circuits, calculation of component values for the device of Achilles tendon reflex. The fifth chapter deals with the ability to view the scanned signal and the final chapter is devoted to measurements of the device on a group of volunteers.

The M.A. thesis Metaphors of Nature in the Czech Weekly 'Reflex' explores the question of how the changing human-nature relationship is reflected in this journal's writing on nature over the period of the last twenty years. The rationale for the choice of the Reflex weekly magazine is that it is not focused on nature or nature-related themes, and thus what we find in it can help us understand how the relationship between humans and nature has changed not only in the journal, but also in society. The principal assumption underlying the present effort is that the many and variegated existing forms of the relationship between humanity and nature transform themselves into various metaphors. By uncovering and analyzing these metaphors we are able to better understand this relationship itself. The theoretical section of this thesis discusses various ways of understanding the metaphor in general, including the conceptual metaphor approach developed by George Lakoff and Mark Johnson which is applied to the textual material in the subsequent empirical section. The theoretical chapters also present a number of metaphors of nature that have previously been analyzed in the literature, and their implications for the human-nature relationship are indicated. The empirical section contains an analysis of the...

This thesis deals with the evaluation of the vestibulo-ocular reflex in patients indicated for neurosurgical resection of vestibular schwannoma, executed at the Motol University Hospital. To evaluate the function of the vestibulo-ocular reflex, three types of clinical examinations were used. In periods before the surgery, early after the surgery and before leaving the hospital we monitored the patients' ability to perceive subjective visual vertical, which reflects tonic function of otolith organs. Before the surgery we also tested relative dynamic visual acuity during passive isolated head movements in the transversal plane, whose impairment is related to dysfunction of lateral semicircular canals. Furthermore, we obtained patients' preoperative values achieved in caloric reflex test. In the early postoperative period, bordered by the first day after the vestibular schwannoma surgery and the last day of the hospitalization, patients underwent specialized vestibular rehabilitation. Based on statistical analysis of acquired data, we found out that in some patients there was a lesion of the vestibulo-ocular reflex already before the surgery and moreover, there was a correlation between dysfunction of translational and rotational parts of the vestibulo-ocular reflex. Although variance of subjective...

The human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) is a worldwide pandemic that affects the lives of millions of people across all ages. Its devastating effects are far-reaching and affect all aspects of an individual’s daily life. HIV/AIDS is responsible for widespread clinical manifestations involving the head and neck. Disorders of the auditory and vestibular systems are often associated with HIV/AIDS, however the extent and nature of these vestibular manifestations is still largely unknown. The main aim of this research study was to investigate vestibular functioning and pathology in adults with HIV/AIDS. This was achieved through three main research steps: a systematic literature review of the body of peer-reviewed literature on HIV/AIDS related vestibular manifestations and pathology, a description and comparison of vestibular involvement in adults with and without HIV/AIDS and an investigation to determine if HIV/AIDS influence the vestibulocollic reflex (VCR) pathways. For the first study a systematic literature review related to vestibular findings in individuals with HIV infection and AIDS was conducted. A varied search strategy was used across several electronic databases to identify relevant peer-reviewed reports in English. Several databases (Medline, Scopus and PubMed) and search strategies were employed. Where abstracts were not available, the full paper was reviewed, and excluded if not directly relevant to the study’s aims. Articles were reviewed for any HIV/AIDS associated vestibular symptoms and pathologies reported. For the second and third study, a cross-sectional, quasi-experimental comparative research design was employed. A convenience sampling method was used to recruit subjects. The sample consisted of 53 adults (29 male, 24 female, aged 23-49 years, mean = 38.5, SD = 4.4) infected with HIV, compared to a control group of 38 HIV negative adults (18 male, 20 female, aged 20-49 years, mean = 36.9, SD = 8.2). A structured interview probed the subjective perception of vestibular complaints and symptoms. Medical records were reviewed for cluster of differentiation 4+ (CD4+) cell counts and the use of antiretroviral (ARV) medication. An otologic assessment and a comprehensive vestibular assessment (bedside assessments, vestibular evoked myogenic potentials, ocular motor and positional tests and bithermal caloric irrigation) were conducted on all subjects. The systematic literature review identified 442 records, reduced to 210 after excluding duplicates, reviews, editorials, notes, letters and short surveys. These were reviewed for relevance to the scope of the study. There were only 13 reports investigating vestibular functioning and pathology in individuals affected by HIV/AIDS. This condition can affect both the peripheral and central vestibular system, irrespective of age and viral disease stage. Post-mortem studies suggest direct involvement of the entire vestibular system, while opportunistic infections such as oto- and neurosyphilis and encephalitis cause secondary vestibular dysfunction resulting in vertigo, dizziness and imbalance. The second study showed an overall vestibular involvement in 79.2% of subjects with HIV in all categories of disease progression, compared to 18.4% in those without HIV. Vestibular involvement increased from 18.9% in the Centers for Disease Control and Prevention (CDC) category 1 to 30.2% in category 2. Vestibular involvement was 30.1% in category 3. There was vestibular involvement in 35.9% of symptomatic HIV positive subjects and 41.5% in asymptomatic HIV positive subjects. Individuals with HIV were 16.6 times more likely to develop vestibular involvement during their lifetime, than among individuals without this disease. Vestibular involvement may occur despite being asymptomatic. The third study showed that abnormal cervical vestibular evoked myogenic potentials and caloric results were significantly higher in the HIV positive group (p=.001), with an odds ratio of 10.2. Vestibulocollic reflex and vestibulo-ocular reflex involvement increased with progression of the disease. There were more abnormal test results in subjects using ARV therapies (66.7%) compared to those not using ARV therapies (63.6%), but this difference was not statistically significant. Vestibular involvement was significantly more common in subjects with HIV than among those without this disease. This disease and its associated risk profile include direct effects of the virus on the vestibular system as demonstrated by postmortem studies. Opportunistic infections may compromise the functioning of the sensory and neural structures of hearing and the vestibular system indirectly, causing vertigo, dizziness or disequilibrium. Ototoxicity may also be related to vestibular dysfunction, due to the ototoxic nature of certain ARV medications. HIV/AIDS influence not only the vestibulo-ocular reflex, but also the vestibulocollic reflex pathways. Primary health care providers could screen HIV positive patients to ascertain if there are symptoms of vestibular involvement. If there are any, then they may consider further vestibular assessments and subsequent vestibular rehabilitation therapy, to minimize functional limitations of quality of life. / Thesis (DPhil)--University of Pretoria, 2014. / lk2014 / Speech-Language Pathology and Audiology / DPhil / Unrestricted

The diploma thesis Content changes of Reflex weekly according to the influence of its editors in chief focuses on the changes which this Czech magazine has gone through from its founding in 1990 to 2013 - during these twenty three years the position of editor in chief changed six times, passing from one person to another. The development of this thesis was based on the supposition that each of the personalities has left their mark on the magazine and has influenced its content according to their experience and preferences. In the theoretical part, the thesis deals with history of the magazine, with changes of editors in chief, the publishers, visual aspects, with the composition of editorial team or magazine sections and also with magazine's direct competitors and the number of editions sold. The following chapter focuses on the theoretical context of the research and refers to the analytical part. Terms as neutrality, negativity and agenda settings are being defined here and the impact of commercialization on visual aspect of the print media is being discussed in this chapter as well. The next part is based on the quantitative content analysis and it examines magazine content in specific periods; both the first and last three months of each editor in chief's era. The analysis outcomes present...

Einleitung: Zur Messung der Narkosetiefe standen bisher vor allem aus dem EEG abgeleitete Parameter im Mittelpunkt der Forschung, die sehr gut geeignet sind, die hypnotische Komponente der Anästhesie abzubilden. Eine Vorhersage auf motorische Reaktionen lassen sie jedoch nicht zu. Eine vorausgehende Studie hat gezeigt, dass unter Sevofluran der spinale H-Reflex mit der chirurgischen Immobilität korreliert. Die vorliegende Studie untersucht, ob motorische Reaktionen während Propofolmononarkosen mittels H-Reflex besser vorausgesagt werden können als mit den EEG-Parametern Bispektraler Index (BIS), spektrale Entropie (SE) und response Entropie (RE). Außerdem wurde der Einfluss von Propofol auf die Erholungskurve des H-Reflexes unter Doppelstimulation untersucht. Methodik: Nach Zustimmung der Ethikkommission und schriftlicher Einwilligung wurden 17 Patienten in die Studie eingeschlossen und ausgewertet. Nach der „up-and-down“-Methode von Dixon wurde die Konzentration von Propofol auf einen Wert eingestellt, bei dem die Hälfte der Patienten auf einen am Unterarm ausgelösten elektrischen Tetanus-Reiz (60 mA) mit einer gezielten motorischen Reaktion reagierten. Nach einer Kontrollmessung wurde die Konzentration von Propofol 15 min konstant gehalten. Danach wurde von einem „steady state“ ausgegangen und der Tetanusreiz wurde ausgelöst. Die Vorhersagefähigkeit der möglichen Narkosetiefe-parameter auf eine Bewegung wurde mit der „Prediction Probability“ (PK-Wert) ermittelt. Im zweiten Teil wurde der H-Reflex anhand der Doppelstimulation mit größer werdenden Interstimulusintervallen (50-8000 ms) untersucht. Ergebnisse: Die Wachwerte für die H-Reflexamplitude liegen bei 5,9 (± 3,8 SD) mV. Der von uns berechnete C50-Tetanus-Wert beträgt 4,5 ± 0,45 mg/l. Die PK-Werte 0,47 für den H-Reflex und 0,45 für die Herzfrequenz lassen nur zufällige Aussagen auf motorische Reaktionen zu. Die EEG-Parameter zeigen höhere PK-Werte: BIS (0,74), SE (0,73), RE (0,71). In diesem Bereich liegt auch der PK-Wert der Propofolzielkonzentration (0,76). Der Schmerzreiz beeinflusste weder die H-Reflexamplitude noch die EEG-Parameter. Bei der Doppelstimulation zeigte sich eine verzögerte Erholung des H-Reflexes unter Doppelstimulation, die am stärksten im Bereich der interkurrenten Fazilitation unter den Interstimulusabständen von 150 und 200 ms. Schlussfolgerung: Für die Vorhersage motorischer Reaktionen während Propofolmono-narkosen sind EEG-Parameter wie BIS, SE und RE etwas besser geeignet als der spinale H-Reflex. Dies steht im Gegensatz zu einer Untersuchung mit Sevofluran und wird auf die unterschiedlichen Wirkmechanismen von volatilen und intravenösen Anästhetika zurückgeführt. Die Unterdrückung der Erholungskurve des H-Reflexes unter Doppelstimula-tion, die vor allem im Bereich der interkurrenten Fazilitation stattfindet, ist möglicherweise durch eine Reduktion supraspinaler exzitatorischer Einflüsse zu erklären. / Introduction: The measurement of „depth of anaesthesia“ is mostly done by parameters of the electroencephalogram (EEG) which can predict hypnosis whereas the prediction of immobility is not possible with those parameters. A previous study has shown that the H-reflex amplitude can be used for monitoring of immobility during sevoflurane anaesthesia. This study examined whether the prediction of movement to painful stimulation is also possible during propofol anaesthesia on the basis of the H-reflex-amplitude compared with the EEG-parameters bispectral index (BIS), spectral entropy (SE) and response entropy (RE). Furthermore the influence of propofol on the H-reflex-recovery under double pulse stimulation was tested. Methods: After approval of the institutional review board and informed consent were obtained, 17 patients were included into this study. Using the “up-and down”-method the concentration of propofol was adjusted to the level where half of the patients do not move to painful stimulation (C50-tetanus-value). Propofol was administered after a baseline measurement. After at least 15 minutes of constant propofol concentration a "steady-state" was assumed and a painful electrical stimulation (tetanic stimulus of 60mA) was applied. To estimate and compare the predictive value of the parameters, prediction probability Pk was calculated. The H-reflex during double pulse stimulation was examined with interstimulus intervals ranging from 50 to 8000 ms. Results: At awake level, H-reflexes had a mean amplitude of 5.9 (+/- 3.8 SD) mV. The calculated C50-tetanus-value was 4.5 (+/- 0.45 SD) mg/l. With Pk-values of 0.47 for the H-reflex amplitude and 0.45 for the heart rate the prediction of movements is just by chance. The Pk-values of the EEG-parameters were higher: BIS (0.74), SE (0.73), RE (0.71). At this level was also the Pk-value of the propofol concentration (0.76). The painful stimulation influenced neither the H-reflex amplitude nor the EEG-parameters. The double pulse stimulation showed a delay in the H-reflex-recovery at interstimulus intervals of 150 and 200 ms. Conclusion: The prediction of movement during propofol anaesthesia is better using the EEG-parameters BIS, SE and RE compared to the H-reflex-amplitude. These results are in contrast to a previous study with sevoflurane which can be explained by the different molecular mechanisms of action of volatile and intravenous anaesthetics. The depression of the recovery-curve of the H-reflex under double pulse stimulation is possibly due to the reduction of supraspinal excitatory influences.

O subnúcleo póstero-dorsal da amígdala medial (AMePD) de ratos modula comportamentos sociais, como é o reprodutivo, e respostas a estímulos estressantes. Para tanto, são necessários ajustes concomitantes da função cardiovascular. Dada sua notável presença no AMePD, o glutamato (GLU), o ácido δ-aminobutírico (GABA), a ocitocina (OT), a somatostatina (SST) e a angiotensina II (Ang II) poderiam estar envolvidos em tais ajustes homeostáticos. O objetivo deste trabalho foi avaliar o efeito da microinjeção de GLU, GABA, OT, SST e Ang II microinjetados diretamente no AMePD de ratos não anestesiados sobre o controle cardiovascular em situação basal e após estimulação dos barorreceptores e quimiorreceptores. Ratos machos Wistar (3 meses de idade) foram mantidos em condições padrão de biotério e cuidados éticos. Os animais foram anestesiados e submetidos à cirurgia estereotáxica para implantação unilateral de cânula no AMePD, lado direito. No quinto dia pós-cirúrgico, os animais foram novamente anestesiados e submetidos à colocação de cateter de polietileno na luz da artéria aorta abdominal e outro na veia cava inferior. Um dia após a canulação dos vasos, os animais foram microinjetados no AMePD com solução salina (0,3 μl; n = 8), GLU na dose de 2 μg/0,3 μl (n = 7), GABA nas doses de 61 ng/0.3μl (n = 7) e de 100 μg/0.3 μl (n = 7), OT nas doses de 10 ng/0,3 μl (n = 7) e de 25 pg/0,3 μl (n = 6), SST nas doses de 1 μM/0,3μl (n = 8) e de 15 fmol/0,3μl (n = 5) e Ang II nas doses de 50 fmol/0,3 μl (n = 7) e de 50 pmol/0,3 μl (n = 7). Dados de frequência cardíaca (FC) e de pressão arterial (PA) foram registrados por 15 minutos em período basal, controle, e, a seguir, foram microinjetadas as substâncias mencionadas e testadas as variáveis de interesse. Os reflexos pressóricos foram testados pela injeção de fenilefrina (8 μg/ml) e nitroprussiato de sódio (100 μg/ml) e os quimiorreceptores, pela de cianeto de potássio (doses crescentes desde 60 até 180 μg/kg). O modelo autoregressivo de análise espectral e a análise simbólica foram utilizados para avaliar a variabilidade da FC e da PA e as atividades simpática e vagal responsáveis pela variabilidade nos dados registrados. Os dados foram comparados pelo teste da análise da variância (ANOVA) de duas vias para medidas repetidas e pelo teste post hoc de Newman- Keuls ou pela ANOVA de uma via e pelo teste de Tukey, conforme apropriado. O nível de significância estatística foi estabelecido em p < 0,05. Não houve diferença estatística entre os grupos estudados nos valores de FC, PA sistólica, PA diastólica e PA média em situação basal ou após as diferentes microinjeções nos grupos microinjetados com neurotransmissores ou com os neuropeptídeos estudados (p > 0,05). Microinjeções de salina, de GLU (2 μg) ou GABA (61 ng ou 100 μg; n = 7 cada grupo) não afetaram os parâmetros basais ou respostas do quimiorreflexo. Os valores correspondentes à curva da modificação da PAM de acordo com a variação da FC foram estatisticamente diferentes entre os grupos estudados, sendo que a curva após a microinjeção de GABA 61 ng no AMePD foi diferente dos grupos que receberam salina ou GABA na maior dose (100 μg; p < 0,05 em ambos os casos). No que se refere ao platô de taquicardia, a curva de inclinação dos dados referente à sensibilidade média do barorreflexo foi diferente entre os grupos que receberam GLU ou GABA em ambas as doses em comparação com o que recebeu salina (p < 0,01). O GLU aumentou valores índices das análises espectral e simbólica simpáticos relacionados com modulações cardíaca e vascular (P <0,05). A administração de GABA (61 ng) também induziu os maiores valores de variabilidade na FC (P <0,05) que pode ser e associado a uma ativação parassimpática central. No grupo de animais microinjetados com salina, OT (10 ng e 25 pg), SST (1μM e 15 fmol) e Ang II (50 fmol e 50 pmol) no AMePD, os valores mais próximos do basal foram obtidos com a menor dose de KCN (60 μg/kg) e ocorreu, conforme o esperado, uma redução estatisticamente significativa maior na FC quando foram aumentadas as doses injetadas de KCN para 100 μg/kg, 140 μg/kg ou 180 μg/kg (teste de Newman-Keuls, p < 0,001 em todos os casos, quando comparadas com a menor dose injetada). Ang II na dose de 50 pmol microinjetada no AMePD gerou maior diminuição reflexa na FC quando comparado com o grupo controle após a estimulação dos quimiorreceptores com KCN nas doses de 60 e 140 μg/kg (p < 0,05). Ang II na dose de 50 pmol microinjetada no AMePD gerou maior diminuição reflexa na PA quando comparado com o grupo controle após a estimulação dos quimiorreceptores com KCN na dose de 140 μg/kg (p < 0,05). Os valores referentes ao ponto de maior inclinação da curva pressórica referente a respostas geradas pelos barorreceptores, (PA50), após injeções de fenilefrina e nitroprussiato de sódio, foram menores nos ratos que receberam OT na dose de 10 ng ou SST na dose de 1 μM microinjetadas no AMePD, quando comparado ao grupo controle (p < 0,05). Os valores referentes à sensibilidade média do barorreflexo (ganho em bpm/mmHg), após injeções de fenilefrina e nitroprussiato de sódio, foi maior no grupo que recebeu OT na dose de 10 ng quando comparado com a Ang II na dose de 50 pmol. Houve maior variabilidade na PA sistólica, na FC, no componente de baixa e de alta frequência do tacograma e no índice de atividade simpático-vagal da análise espectral nos grupos que receberam OT nas doses de (10 ng e 25 pg), SST (1μM e 15 fmol) e Ang II na dose de 50 pmol (p < 0,05). Tais dados, indicam que o AMePD se vale de sua atividade glutamatérgica, GABAérgica, ocitocinérgica, somatostatinérgica e angiotensinérgica local, por circuitaria própria ou devido a aferências neurais, para modificar variáveis cardiovasculares provavelmente concomitantemente à organização de comportamentos. / The postero-dorsal subnucleus of the medial amygdala (MePD) modulates social behavior of rats, such as reproduction, and responses to stressful stimuli. To this end, concomitants adjustments of the cardiovascular function are modulate. Given its remarkable presence in the MePD, glutamate (GLU), Gamma-amino butyric acid (GABA), oxytocin (OT), somatostatin (SST) and angiotensin II (Ang II) could be involved in such homeostatic adjustments. The objective of this study was to evaluate the effect of microinjection of GLU, GABA, OT, SST and Ang II microinjected directly into the rats MePD on non-anesthetized of cardiovascular control under basal conditions and after stimulation of baroreceptors and chemoreceptors. Male Wistar rats (3 months old) were maintained under standard laboratory conditions and ethical care. The animals were anesthetized and submitted to unilateral stereotactic surgery for implantation of the cannula in the right MePD. On the fifth postoperative day, the animals were again anesthetized and underwent placement of polyethylene catheter in the abdominal aorta and inferior vena cava. One day after the cannulation of the vessels, the animals were microinjected with saline solution, GLU (2 μg/0,3 μl, n = 7), GABA (61 ng/0.3μl, n = 7 and 100 μg/0.3 μl, n = 7), OT (10 ng/0,3 μl, n = 7 and 25 pg/0,3 μl, n = 6), SST (1 μM/0,3μl, n = 8 and 15 fmol/0,3μl, n = 5) and Ang II (50 fmol/0,3 μl, n = 7 and 50 pmol/0,3 μl, n = 7) in the MePD. Data for heart rate (HR) and blood pressure (BP) were recorded for 15 minutes at baseline and then were microinjected the substances aforementioned and tested the variables of interest. Baroreceptor function was tested by phenylephrine (8 μg/ml) and sodium nitroprusside (100 μg/ml) injections. Chemoreflex was tested by potassium cyanide (60 – 180 μg/ml) injections. The autoregressive model of symbolic analysis and spectral analysis were used to evaluate the variability of HR and BP and the sympathetic and vagal activities responsible for variability in the data recorded. The data were compared by a two-way analysis of variance (ANOVA) test for repeated measures and the post hoc Newman-Keuls or an one-way analysis of variance (ANOVA) test for repeated measures and the post hoc Newman-Keuls whenever appropriate. The level of statistical significance was set at P ≤ 0.05. There was no statistical difference between groups in the values of HR, systolic BP, diastolic BP and mean BP at baseline or after microinjections in the different groups (P > 0.05). Microinjections of saline, GLU (2 μg) or GABA (61 ng or 100 μg; n = 7 each group) did not affect the basal or responses the of chemoreflex. The values of the curve of change in the MAP in accordive to the variation of HR, were statistically different between groups, and the curve after the microinjection of GABA 61 ng in the MePD was different in the groups that received saline or the highest GABA dose (100 μg, P < 0.05 in both cases). With regard to the plateau of tachycardia, the slope of the data on the average baroreflex sensitivity was different among the groups receiving GLU or GABA at both doses compared to that received saline (P < 0.01). GLU increased power spectral and symbolic sympathetic indexes related with both cardiac and vascular modulations (P < 0.05). The GABA administration (61 ng, but not 100 μg) also induced higher values of HR variability (P < 0.05), rather associated with a parasympathetic activation. In the group of animals microinjected with saline, OT (10 ng and 25 pg), SST (1μM and 15 fmol) and Ang II (50 fmol and 50 pmol) in MePD, there was as expected, a statistically significant greater reduction in HR increasing when the injected doses of KCN to 100 μg/kg, 140 μg/kg or 180 μg/kg (Newman-Keuls test, P < 0.001 in all cases when compared with the lower injected dose). Ang II at the dose of 50 pmol generated a higher reflex decrease in HR compared to the control group after stimulation of the chemoreceptors with KCN at doses of 60 and 140 μg/kg (P < 0.05). Ang II at the dose of 50 pmol generated a higher reflex decrease in BP compared with the control group after stimulation of the chemoreceptors with KCN at the dose of 140 μg/kg (P < 0.05). The values for the point of greatest slope of the AP response generated by baroreceptors (MAP50) was lower in rats given OT at the dose of 10 ng or SST at the dose of 1 μM compared to the control group (P < 0.05). The average values for the baroreflex sensitivity (gain in bpm/mm Hg) after the injection of phenylephrine and sodium nitroprusside was greater in the group receiving OT at the dose of 10 ng compared with Ang II at the dose of 50 pmol. There was a greater variability in systolic BP, HR, the component of low and high frequency of tachogram and the sympathovagal index studied by spectral analysis in the groups that received OT (10 ng and 25 pg), SST (1 μM and 15 fmol) and Ang II (50 pmol; P < 0.05). These data indicate that the MePD has a glutamatergic, GABAergic, ocitocinergic, somatostatinergic angiotensinergic modulatory activity on cardiovascular response most likely involved in the central organization of behaviors.

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