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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Estimulação colinérgica com piridostigmina reduz arritmia ventricular e aumenta a variabilidade da frequência cardíaca em pacientes com insuficiência cardíaca

Behling, Alice January 2001 (has links)
INTRODUÇÃO. O aumento da densidade de arritmia ventricular e a redução da variabilidade da freqüência cardíaca estão associados com risco de morte súbita e mortalidade total em insuficiência cardíaca. A inibição colinesterásica com brometo de piridostigmina (PIR) aumenta a variabilidade da freqüência de pessoas normais, porém seu efeito em pacientes com insuficiência cardíaca é desconhecido. OBJETIVOS. Testar a hipótese de que a administração a curto prazo de piridostigmina reduz a densidade de arritmia ventricular e aumenta a variabilidade da freqüência cardíaca em pacientes com insuficiência cardíaca. MÉTODOS. Pacientes com insuficiência cardíaca e em ritmo sinusal participaram de um estudo duplo-cego, cruzado, randomizado para placebo e piridostigmina (30mg VO de 8 em 8 horas por 2 dias). Monitorização eletrocardiográfica ambulatorial de 24 horas foi realizada para análise de arritmia e para avaliação dos índices do domínio do tempo da variabilidade da freqüência cardíaca. Pacientes foram separados em 2 grupos, de acordo com a densidade de arritmia ventricular. O grupo Arritmia (n = 11) incluiu pacientes com mais de 10 extrassístoles ventriculares por hora (ESV/h), e o grupo Variabilidade da Freqüêcia Cardíaca (n = 12) incluiu pacientes com um número de ESVs em 24 horas que não excedia 1 % do número total de intervalos RR. RESULTADOS. No grupo Arritmia, PIR resultou em uma redução de 65% no número de extrassístoles ventriculares (Placebo 266 + 56 ESV/h vs. PIR 173 + 49 ESV/h; p = 0,03). No grupo da Variabilidade da Freqüência Cardíaca, a administração de PIR resultou em um aumento do intervalo RR médio (Placebo 733 + 22 ms vs PIR 790 + 33 ms; p = 0,01), e nos índices do domínio do tempo da variabilidade da freqüência cardíaca PNN50 (Placebo 3 + 1,1 % vs PIR 6 + 1,6 %; p = 0,03) e RMSSD (Placebo 21 + 2 vs PIR 27 + 3; p = 0,008). CONCLUSÃO. Em pacientes com insuficiência cardíaca, PIR reduziu a densidade de arritmia ventricular e aumentou a VFC, provavelmente por seu efeito colinomimético. Estudos a longo prazo com PIR em insuficiência cardíaca devem ser realizados. / OBJECTIVE To test the hypothesis that short-term administration of pyridostigmine bromide (PYR) reduces ventricular arrhythmia density and increases heart rate variability in patients with congestive heart failure. BACKGROUND Increased ventricular arrhythmia density and reduced heart rate variability are associated with risk of sudden death and overall mortality in patients with heart failure. Cholinesterase inhibition with pyridostigmine bromide increases heart rate variability in normal subjects, but its effect in patients with heart failure is unknown. METHODS Patients with heart failure and in sinus rhythm participated in a double-blind, cross-over protocol, randomized for placebo and pyridostigmine (30 mg PO TID for 2 days). Twenty-four hour electrocardiographic recordings were performed for arrhythmia analysis and for the measurement of time domain indices of heart rate variability. Patients were separated in 2 groups, according to their ventricular arrhythmia density. The Arrhythmia Group (n = 11) included patients with more than 10 ventricular premature beats per hour (VPBs/h), and the Heart Rate Variability Group (n = 12) included patients with a number of VPBs in 24 hours not exceeding 1 % of the total number of RR intervals. RESULTS For the Arrhythmia Group, PYR resulted in 65 % reduction of ventricular ectopic activity (Placebo 266 ± 56 VPBs/h vs. PYR 173 ± 49 VPBs/h; P = 0.03). For the Heart Rate Variability Group, PYR administration resulted in an increment of mean RR interval (Placebo 733 ± 22 msec vs PYR 790 ± 33 msec; P = 0.01), and in the time domain indices of heart rate variability RMSSD (Placebo 21± 2 vs PYR 27 ± 3; P = 0.01) and PNN50 (Placebo 3 ± 1 % vs PYR .6 ± 2 %; P = 0.03). CONCLUSION In patients with heart failure, PYR reduced ventricular arrhythmia density and increased HRV, most likely due to its cholinomimetic effect. Long-term trials with PYR in heart failure should be conducted.
12

Influência da neuromodulação parassimpática durante a indução da periodontite em camundongos / Influence of parasympathetic neuromodulation during periodontitis induction in mice

Santana, Juliana Bueno [UNESP] 22 February 2016 (has links)
Submitted by JULIANA BUENO SANTANA null (juli_bsantana@hotmail.com) on 2016-05-05T15:29:58Z No. of bitstreams: 1 Dissertação final.pdf: 1846480 bytes, checksum: 4a7009afba6cc2b58f17ba4282681092 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-09T13:47:58Z (GMT) No. of bitstreams: 1 santana_jb_me_sjc.pdf: 1846480 bytes, checksum: 4a7009afba6cc2b58f17ba4282681092 (MD5) / Made available in DSpace on 2016-05-09T13:47:58Z (GMT). No. of bitstreams: 1 santana_jb_me_sjc.pdf: 1846480 bytes, checksum: 4a7009afba6cc2b58f17ba4282681092 (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A doença periodontal (DP) é uma das infecções mais comuns dos seres humanos e é caracterizada pela destruição dos tecidos de suporte dentários, incluindo o osso alveolar. Recentemente tem sido demonstrado que a regulação sistêmica da remodelação óssea é feita também por duas ramificações do Sistema Nervoso Autônomo: a simpática, que favorece a perda óssea, e a parassimpática, que favorece o acréscimo de massa óssea. O objetivo desse trabalho foi verificar, através da administração de inibidores da acetilcolinesterase, o efeito da neuromodulação parassimpática na DP induzida e no tecido ósseo em camundongos. Foram utilizados 40 camundongos machos, divididos em 4 grupos: (1) Grupo Galantamina (G), dez animais com DP induzida e tratados com 3 mg/Kg/dia de Galantamina; (2) Grupo Donepezil (D), dez animais com DP induzida e tratados com 2 mg/Kg/dia de donepezil; (3) Grupo Ligadura (L), dez animais com DP induzida; e (4) Grupo Controle (C). A indução da doença periodontal foi realizada com a inserção de fio de algodão ao redor dos primeiros molares inferiores e o tratamento durou 42 dias. No dia do sacrifício, amostras de sangue foram coletadas para análise sorológica do fator nuclear κB ligante (RANKL) e osteoprotegerina (OPG). As hemimandíbulas esquerdas foram submetidas à análise histomorfométrica e os fêmures esquerdos, ao teste de flexão em três pontos para avaliação das propriedades extrínsecas e intrínsecas. O uso dos medicamentos não reduziu a perda óssea alveolar dos grupos tratados. Também não foram observadas diferenças estatísticas significantes com relação às propriedades biomecânicas dos fêmures ou à concentração sérica de RANKL e OPG. Concluímos que a galantamina e o donepezil, nas doses e período utilizados, não influenciaram a patogênese da DP ou a remodelação óssea sistêmica. / Periodontal disease (PD) is one of the most common infections of human beings, and it is characterized by destruction of tooth supporting tissues, including alveolar bone. Recently it has been shown that the systemic regulation of bone remodeling is also made by two branches of the autonomic nervous system: the sympathetic, favoring bone loss and the parasympathetic, which promotes increase of bone mass. The aim of this study was to verify, through the administration of acetylcholinesterase inhibitors, the effect of parasympathetic neuromodulation in induced periodontitis and bone tissue in mice. Forty male mice were divided into 4 groups: (1) Group Galantamine (G), ten animals with induced PD and treated with 3 mg/ kg/day of galantamine; (2) Donepezil group (D), ten animals with induced PD and treated with 2 mg/kg/day of donepezil; (3) Ligature group (L), ten animals with induced PD; and (4) control group (C). The induction of periodontal disease was carried out with a cotton thread insertion around the lower first molars and the treatment lasted 42 days. On the day of sacrifice, animalsblood samples were collected for serological analysis of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG). The left hemimandibles were submitted to histomorphometric analysis and the left femur to the three point bending test for assessment of extrinsic and intrinsic properties. The use of the drugs did not reduce alveolar bone loss in treated groups. No statistically significant differences regarding the biomechanical properties of femurs or serum RANKL and OPG were observed. We conclude that galantamine and donepezil, at doses and time used, did not influence the pathogenesis of PD or systemic bone remodeling. / CNPq: 459759/2014-0
13

Estimulação colinérgica com piridostigmina reduz arritmia ventricular e aumenta a variabilidade da frequência cardíaca em pacientes com insuficiência cardíaca

Behling, Alice January 2001 (has links)
INTRODUÇÃO. O aumento da densidade de arritmia ventricular e a redução da variabilidade da freqüência cardíaca estão associados com risco de morte súbita e mortalidade total em insuficiência cardíaca. A inibição colinesterásica com brometo de piridostigmina (PIR) aumenta a variabilidade da freqüência de pessoas normais, porém seu efeito em pacientes com insuficiência cardíaca é desconhecido. OBJETIVOS. Testar a hipótese de que a administração a curto prazo de piridostigmina reduz a densidade de arritmia ventricular e aumenta a variabilidade da freqüência cardíaca em pacientes com insuficiência cardíaca. MÉTODOS. Pacientes com insuficiência cardíaca e em ritmo sinusal participaram de um estudo duplo-cego, cruzado, randomizado para placebo e piridostigmina (30mg VO de 8 em 8 horas por 2 dias). Monitorização eletrocardiográfica ambulatorial de 24 horas foi realizada para análise de arritmia e para avaliação dos índices do domínio do tempo da variabilidade da freqüência cardíaca. Pacientes foram separados em 2 grupos, de acordo com a densidade de arritmia ventricular. O grupo Arritmia (n = 11) incluiu pacientes com mais de 10 extrassístoles ventriculares por hora (ESV/h), e o grupo Variabilidade da Freqüêcia Cardíaca (n = 12) incluiu pacientes com um número de ESVs em 24 horas que não excedia 1 % do número total de intervalos RR. RESULTADOS. No grupo Arritmia, PIR resultou em uma redução de 65% no número de extrassístoles ventriculares (Placebo 266 + 56 ESV/h vs. PIR 173 + 49 ESV/h; p = 0,03). No grupo da Variabilidade da Freqüência Cardíaca, a administração de PIR resultou em um aumento do intervalo RR médio (Placebo 733 + 22 ms vs PIR 790 + 33 ms; p = 0,01), e nos índices do domínio do tempo da variabilidade da freqüência cardíaca PNN50 (Placebo 3 + 1,1 % vs PIR 6 + 1,6 %; p = 0,03) e RMSSD (Placebo 21 + 2 vs PIR 27 + 3; p = 0,008). CONCLUSÃO. Em pacientes com insuficiência cardíaca, PIR reduziu a densidade de arritmia ventricular e aumentou a VFC, provavelmente por seu efeito colinomimético. Estudos a longo prazo com PIR em insuficiência cardíaca devem ser realizados. / OBJECTIVE To test the hypothesis that short-term administration of pyridostigmine bromide (PYR) reduces ventricular arrhythmia density and increases heart rate variability in patients with congestive heart failure. BACKGROUND Increased ventricular arrhythmia density and reduced heart rate variability are associated with risk of sudden death and overall mortality in patients with heart failure. Cholinesterase inhibition with pyridostigmine bromide increases heart rate variability in normal subjects, but its effect in patients with heart failure is unknown. METHODS Patients with heart failure and in sinus rhythm participated in a double-blind, cross-over protocol, randomized for placebo and pyridostigmine (30 mg PO TID for 2 days). Twenty-four hour electrocardiographic recordings were performed for arrhythmia analysis and for the measurement of time domain indices of heart rate variability. Patients were separated in 2 groups, according to their ventricular arrhythmia density. The Arrhythmia Group (n = 11) included patients with more than 10 ventricular premature beats per hour (VPBs/h), and the Heart Rate Variability Group (n = 12) included patients with a number of VPBs in 24 hours not exceeding 1 % of the total number of RR intervals. RESULTS For the Arrhythmia Group, PYR resulted in 65 % reduction of ventricular ectopic activity (Placebo 266 ± 56 VPBs/h vs. PYR 173 ± 49 VPBs/h; P = 0.03). For the Heart Rate Variability Group, PYR administration resulted in an increment of mean RR interval (Placebo 733 ± 22 msec vs PYR 790 ± 33 msec; P = 0.01), and in the time domain indices of heart rate variability RMSSD (Placebo 21± 2 vs PYR 27 ± 3; P = 0.01) and PNN50 (Placebo 3 ± 1 % vs PYR .6 ± 2 %; P = 0.03). CONCLUSION In patients with heart failure, PYR reduced ventricular arrhythmia density and increased HRV, most likely due to its cholinomimetic effect. Long-term trials with PYR in heart failure should be conducted.
14

Variabilidade da freqüência cardíaca como ferramenta de análise da função autonômica: revisão de literatura e comparação do comportamento autonômico e metabólico em recuperação pós-exercício

Hoshi, Rosangela Akemi [UNESP] 14 August 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-14Bitstream added on 2014-06-13T19:08:19Z : No. of bitstreams: 1 hoshi_ra_me_prud.pdf: 470187 bytes, checksum: 5cba677581b43beb6b7309e781ff9714 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O sistema nervoso autônomo (SNA) desempenha um papel importante na regulação dos processos fisiológicos do organismo humano tanto em condições normais quanto patológicas. Dentre as técnicas utilizadas para sua avaliação, a variabilidade da frequência cardíaca (VFC) tem emergido como uma medida simples e não-invasiva dos impulsos autonômicos, representando um dos mais promissores marcadores quantitativos do balanço autonômico. A VFC descreve as oscilações no intervalo entre batimentos cardíacos consecutivos (intervalos R-R), assim como oscilações entre frequências cardíacas instantâneas consecutivas. Trata-se de uma medida que pode ser utilizada para avaliar a modulação do SNA sob condições fisiológicas, tais como em situações de vigília e sono, diferentes posições do corpo, treinamento físico, e também em condições patológicas. Mudanças nos padrões da VFC fornecem um indicador sensível e antecipado de comprometimentos na saúde. Uma alta variabilidade na frequência cardíaca é sinal de boa adaptação, caracterizando um indivíduo saudável, com mecanismos autonômicos eficientes, enquanto que, baixa variabilidade é frequentemente um indicador de adaptação anormal e insuficiente do SNA, implicando a presença de mau funcionamento fisiológico no indivíduo. Diante da sua importância como um marcador que reflete a atividade do SNA sobre o nódulo sinusal e como uma ferramenta clínica para avaliar e identificar comprometimentos na saúde, este artigo revisa aspectos conceituais da VFC, dispositivos de mensuração, métodos de filtragem, índices utilizados para análise da VFC, limitações de utilização e aplicações clínicas da VFC. / Autonomic nervous system (ANS) plays an important role in the regulation of the physiological processes of the human organism during normal and pathological conditions. Among the techniques used in its evaluation, the heart rate variability (HRV) has arising as a simple and non-invasive measure of the autonomic impulses, representing one of the most promising quantitative markers of the autonomic balance. The HRV describes the oscillations in the interval between consecutive heart beats (RR interval), as well as the oscillations between consecutive instantaneous heart rates. It is a measure that can be used to assess the ANS modulation under physiological conditions, such as wakefulness and sleep conditions, different body positions, physical training and also pathological conditions. Changes in the HRV patterns provide a sensible and advanced indicator of health involvements. Higher HRV is a signal of good adaptation and characterizes a health person with efficient autonomic mechanisms, while lower HRV is frequently an indicator of abnormal and insufficient adaptation of the autonomic nervous system, provoking poor patient's physiological function. Because of its importance as a marker that reflects the ANS activity on the sinus node and as a clinical instrument to assess and identify health involvements, this study reviews conceptual aspects of the HRV, measurement devices, filtering methods, indexes used in the HRV analyses, limitations in the use and clinical applications of the HRV.
15

Envolvimento da via colinergica na hiperinsulinemia induzida por glicocorticoide em ratos / Involvement of the cholinergic pathway in the glucocorticoid-induced hyperinsulinemia in rats

Angelini, Nagela 13 August 2018 (has links)
Orientador: Jose Roberto Bosqueiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T20:49:58Z (GMT). No. of bitstreams: 1 Angelini_Nagela_M.pdf: 1358649 bytes, checksum: fa79dc1fdebb1f263e4c5e7db9dfb597 (MD5) Previous issue date: 2009 / Resumo: Em adultos, a massa de célula ? é mantida por um balanço entre proliferação, tamanho, neogênesis e morte de célula ?. A resistência à insulina (RI) perturba esta regulação e altera o crescimento e a sobrevivência destas células, promovendo um aumento compensatório da massa de céulas ? e secreção de insulina. Neste trabalho nos investigamos a contribuição do sistema nervoso parassimpático na RI induzida por Dexametasona (DEX) e hiperinsulinemia em ratos. Ratos Wistar de 70 dias foram divididos em três grupos: Controle (CTL), vagotomizados (VAG) e sham operados (SHAM). Aos 90 dias de vida metade dos animais de cada grupo foram tratados com 1 mg/kg de DEX por 5 dias consecutivos (CTL DEX, VAG DEX e SHAM DEX). Na presença de glicose 8.3 mM mais Carbacol (Cch) 100 ?M ilhotas isoladas CTL DEX secretaram significantemente mais insulina que ilhotas CTL. Não foi obervado diferença na secrecão de insulina entre CTL e SHAM ou entre CTL DEX e SHAM DEX. Entretanto ilhotas de VAG DEX secretaram significantemente mais insulina. A potencialização da secreção de insulina estimulada pela glicose (SIEG) frente ao estímulo do agonista colinérgico (Cch) foi significantemente maior em ilhotas VAG CTL e VAG DEX que SHAM CTL e SHAM DEX, respectivamente. Em ilhotas CTL DEX o conteúdo das proteínas M3R e PLC?1, mas não PKC?, foi significantemente maior comparado com seus respectivos controles. Entretanto, pPKC? aumentou significantemente em CTL DEX. Em ilhotas VAG DEX a expressão da proteína M3R aumentou significantemente comparado com VAG CTL e SHAM DEX. A vagotomia per se não afetou a RI, mas atenuou a insulinemia de jejum e alimentado em VAG DEX vs SHAM DEX . Em conclusão, este trabalho indica uma importante participação do sistema nervoso parassimpático através do receptor muscarínico na hiperinsulinemia / Abstract: In adults, the beta-cell mass is maintained via a balance of beta-cell proliferation, size, neogenesis, and beta-cell death. The insulin-resistant state disrupts this regulation and alters beta-cell growth and survival, promoting a compensatory increase in beta-cell mass and insulin secretion. Here, we investigated the contribution of the cholinergic nervous system to dexamethasone-induced insulin resistance and hyperinsulinemia in rats. Seventy-day-old Wistar male rats were distributed in three groups, control (CTL), vagotomized (VAG), and sham operated (SHAM). On the 90th day of life, half of the rats were treated daily with 1 mg/kg of dexamethasone for 5 days (CTL DEX, VAG DEX, and SHAM DEX). In the presence of 8.3 mM glucose plus 100 µM carbachol (Cch), isolated islets from CTL DEX secreted significantly more insulin than CTL. No differences in insulin secretion were observed between CTL and SHAM or CTL DEX and SHAM DEX. However, islets from VAG DEX secreted significantly more insulin than SHAM DEX. Cch-potentialization of secretion was further increased in islets from VAG CTL and VAG DEX than SHAM CTL and SHAM DEX, respectively. In CTL DEX islets, M3R and PLC?1, but not PKC?, protein content was significantly higher compared with each respective control; however, pPKC? was significantly increased in the CTL DEX. In islets from VAG DEX, the expression of M3R protein increased significantly compared to VAG CTL and SHAM DEX. Vagotomy per se did not affect insulin resistance, but attenuated fasted and fed insulinemia in VAG DEX, compared with SHAM DEX rats. In conclusion, these data indicate an important participation of the cholinergic nervous system through muscaric receptors in dexamethasone-induced hyperinsulinemia in rats / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular
16

The Parasympathetic Nervous System in Human Heart Failure

French, Jessica Autumn 26 May 2011 (has links)
No description available.
17

Autonomic Nervous System Functioning in Posttraumatic Stress Disorder at Rest and During Stress: The Role of the Parasympathetic Nervous System

Keary, Therese A. 26 August 2008 (has links)
No description available.
18

Testing emotion regulation and parasympathetic nervous system deficits as a mechanism for the transmission of borderline personality disorder

Richmond, Julia R. 06 June 2017 (has links)
No description available.
19

Psychophysiological distinctions in emotional responding: sensitivity to perceiving loss of connection

Seah, Lily 10 May 2023 (has links)
The study investigated how distinctions in perception might affect emotional responding to a change in an affordance. There is evidence that Europeans tend to perceive salient objects in the foreground, while East Asians tend to perceive holistically. Due to sensitivity to focal objects, European Americans (EA) were hypothesized to respond negatively with increased HR variance on perceiving loss of connection when playing Cyberball. EA would also feel sadness more intensely, in terms of decreased heart rate and increased RSA, at an earlier time during a sad clip. Chinese Americans (CA) were predicted to show no difference in affect from controls. ECG, fEMG, respiration and self-report data were acquired from 51 subjects (38 EA, 13 CA, 25 male, mean age 21.1) in a between-subjects design. 26 subjects (19 EA, 6 CA) received 2 out of 48 balls tossed and the controls received 10. 88% in the experimental condition reported a negative emotion (e.g. anger). Control subjects reported mainly neutral affect. ANOVA analyses revealed HR variance had an interaction effect (time x condition, p=0.009) and RSA had a main effect (condition, p=0.033). Both experimental groups had increased heart rate variance and increased RSA. Facial coding revealed EA expressed more negative emotion. CA in the experimental condition showed correlation across measures: HR variance, RSA and respiration, suggesting automatic regulation to perceiving loss contained its expression. Most subjects reported feeling sad during the clip. fEMG of the corrugator muscle revealed EA activated higher peak intensity 5.5 seconds earlier than CA (increased 1.571 vs 0.844). EA also had decreased HR and increased RSA, a sign of withdrawal in sadness, earlier. Evidence suggests exposure to loss had stronger effect on EA to increase their arousal and sensitivity thereafter. / M.S. / The study investigated how differences in perceiving a change in social connection might affect emotional responses. There is evidence that Europeans tend to perceive salient objects in the foreground, while East Asians tend to perceive holistically. Due to sensitivity to focal objects, European Americans (EA) were hypothesized to respond negatively with increased heart rate variance on perceiving loss of connection when playing Cyberball, a ball-tossing video game. EA would also feel sadness more intensely, in terms of decreased heart rate and increased vagal activation, at an earlier time during a sad clip. Chinese Americans (CA) were predicted to show no difference in affect from controls. ECG, fEMG, respiration and self-report data were acquired from 51 subjects (38 EA, 13 CA, 25 male, mean age 21.1) in a between-subjects design. 26 subjects (19 EA, 6 CA) received 2 out of 48 balls tossed and the controls received 10. 88% in the experimental condition reported a negative emotion (e.g. anger). Control subjects reported mainly neutral affect. Unexpectedly, both experimental groups had increased heart rate variance. CA in the experimental condition showed correlation across physiological measures: heart rate variance, vagal activation and respiration, suggesting automatic regulation to perceiving loss during Cyberball. These correlations were not observed in the EA, but as predicted, EA in the experimental condition had decreased heart rate and increased vagal activation, a sign of withdrawal in sadness, earlier during a sad clip. Evidence suggests exposure to loss had stronger effect on EA to increase their arousal and sensitivity thereafter.
20

Altered Autonomic Nervous System Function in Chickens Divergently Selected for Body Weight

Kuo, Alice Yi-Wen 01 September 2000 (has links)
Autonomic nervous system activity is related to body weight regulation. Based on the MONA LISA hypothesis it has been suggested that most obese subjects and animals have low sympathetic nervous system activity. The aim of this study was to investigate whether there are differences in autonomic nervous system activity between lines of chickens selected for either high (HWS) or low body weight (LWS). In Exp. 1, various pharmacological agents were injected intravenously, and the changes in blood pressure (BP) and heart rate (HR) of both HWS and LWS chickens were compared. The results showed that the HWS birds had a greater increase in BP and HR than the LWS following injection of atropine, a muscarinic receptor blocker, and LWS birds had a greater decrease in BP and HR to propranolol, a beta- adrenergic receptor blocker than the HWS birds. These results suggested that HWS chickens have higher parasympathetic tone, whereas LWS chickens have a higher sympathetic nervous system tone regulating the cardiovascular system. HWS and LWS chickens displayed a similar response in BP and HR following injection of the ganglion blocker tetraethylammonium chloride. These results suggest that there is no significant difference in the central autonomic nervous system in the cardiovascular regulation between HWS and LWS together. Since there does not appear to be any differences in the activity of the autonomic nervous system activity at the level of the central nervous system, these findings imply that the difference in response to atropine and propranolol could be caused by differences in adrenal activity. The ratio of heart rate and blood pressure after the injection of phenylephrine showed significant difference between these two lines of birds, but not when phenylephrine was injected following atropine. This result indicated that HWS are more dependent on the parasympathetic nervous system to regulate the baroreceptor reflex. The percentage of adrenal and sympathetic impact on the regulation of heart rate showed that LWS females required greater adrenal activity than the other birds. In Exp. 2, the body weight and food intake responses of HWS and LWS chickens to ip injections of reserpine were compared. Reserpine caused a transitory decrease in food intake and body weight in both lines of birds. However HWS chickens recovered more slowly from the depression caused by reserpine than the LWS chickens. This could be due to lower sympathetic nervous system activity. In conclusion, it appears that HWS may have lower sympathetic activity than LWS. Combining the results of both experiments, it appears that the HWS birds have lower sympathetic and higher parasympathetic activity. Furthermore central nervous system autonomic activity in BP and HR regulation is not different between HWS and LWS, but the activity of the adrenal gland may be different between these two lines of birds. / Master of Science

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