Durante situações aversivas, como choque nas patas, imobilidade ou restrição dos movimentos, há um aumento nos níveis de acetilcolina no hipocampo de ratos. Além disso, o aumento desse neurotransmissor está envolvido com a modulação comportamental do MCC, principalmente em sua porção dorsal, HD. Diante disso, é proposto neste estudo que os receptores muscarínicos presentes no HD de ratos, modulam a expressão da REC, no modelo do MCC. Ratos wistar foram submetidos às sessões de condicionamento aversivo contextual, sendo divididos nos grupos: condicionado (6 choques de 3s; 1,5 mA) e não condicionado (sem choques) . Quarenta e oito horas após esta sessão foram avaliadas a comportamental (congelamento) e respostas autonômicas (PAM, FC e queda da TC). Além disso, foi verificada a distribuição de receptores M1 e M3 nas subáreas do HD e a quantificação dos mesmos em animais condicionados, não condicionados e naive, 48 após a sessão de condicionamento. A microinjeção bilateral de hemicolínio, inibidor da captação de colina, no HD promoveu uma redução do tempo de congelamento durante a reexposição ao contexto aversivo, caracterizando um efeito do tipo ansiolítico. Além disso, este tratamento inibiu o aumento da PAM, FC e a queda da TC induzidos pelo MCC. O mesmo ocorreu com a administração de atropina, antagonista não seletivo de receptores muscarínicos, de forma dose-dependente em todas as respostas observadas. Adicionalmente, a microinjeção de diferentes doses de J104129 fumarate bloquearam o tempo de congelamento (de forma dose-dependente, semelhante a atropina), a elevação da PAM, FC e a queda da TC durante a re-exposição ao contexto aversivo. Como o J104129 fumarate bloqueia receptores muscarínicos tanto M1 quanto M3, foi utilizado um antagonista de maior afinidade para receptores do tipo M1, pirenzepina. Todas as doses utilizadas de pirenzepina inibiram as respostas autonômicas, sem afetar o tempo de congelamento induzidos pelo MCC. A análise de imunofluorescência, por duplamarcação, mostrou que receptores M1 e M3 estão distribuídos nos mesmos compartimentos celulares nas subáreas do HD. A quantificação dos receptores 48 horas após o condicionamento evidencia apenas o aumento de receptores M3 no hipocampo de ratos, sem alteração na população de receptores M1. Com este conjunto de resultados podemos concluir que a ACh no HD é essencial para a expressão da REC. Especificamente, eles sugerem que os receptores muscarínicos do tipo M1 presentes nesta estrutura estão envolvidos com as respostas autonômicas e somente os receptores M3 participam das respostas comportamentais. / During aversive and stressful situations, such as footshock, stillness and restriction of movements, there is an increase in the levels of acetylcholine in rat hippocampus. Moreover, the increasing in the synaptic level of this neurotransmitter is involved with behavioral modulation of contextual fear conditioning (CFC), especially in the dorsal portion, DH. Therefore, this study investigated the involvement of muscarinic receptors in DH of rats in the expression of conditioned emotional response (CER) in the CFC. Moreover, we verified the expression of these receptors in the DH by double labeling immunofluorescence. Male Wistar rats were subjected to aversive contextual conditioning sessions and were divided into two groups: conditioned and unconditioned. Forty-eight hours after this session were evaluated autonomic (mean arterial pressure, MAP, heart rate, HR and tail temperature, TT) and behavioral (freezing) responses. Moreover, the distribution of M1/M3 receptors in subareas of DH was observed and the quantification of these receptors were performed 48 hours after the conditioning session in conditioned, unconditioned and naive animals. The bilateral microinjection of hemicholinium, inhibitor of choline reuptake, in DH, caused a decrease of freezing during re-exposure to the aversive context, featuring an anxiolytic-like effect. Furthermore, this treatment inhibited the increase in MAP, HR and TT drop by CFC. DH muscarinic receptors antagonism evoked by atropine, a non-selective muscarinic antagonist, reduced the freezing, in a dose-dependent manner. Similar reduction was observed in autonomic responses. The selective antagonism of M1/M3 receptors evoked by J104129 fumarate also reduced freezing, in a dose-dependent manner, when compared with control animals. The same effect was observed with autonomic responses in all the tested doses. As J104129 fumarate blocks both M1 muscarinic as M3 muscarinic, was used a higher-affinity M1 antagonist, pirenzepine. All doses inhibited cardiovascular responses and decrease the TT drop, without affecting the freezing induced by CFC. The immunofluorescence analysis revealed that M1 and M3 receptors are distributed in the same cellular compartments in DH. The quantification of receptors showed an increase of M3 receptors in rat hippocampus, while no change in the density of receptors M1 was detected. These findings support that cholinergic neurotransmission present in DH is involved with the expression of responses evoked by fear contextual conditioning, through muscarinic receptors activation. In particular, M3 muscarinic receptors modulate behavioral responses, M1 and M3 muscarinic receptors modulate the autonomic responses.

O sistema nervoso (SN) autonômico é fundamental na regulação cardiovascular. A análise da variabilidade da freqüência cardíaca (VFC), no domínio do tempo e da freqüência, expressa a modulação autonômica cardíaca, pois reflete a atividade do SN simpático (receptores adrenérgicos) e do SN parassimpático (receptores muscarínicos) sobre Nó Sinoatrial. As variantes genéticas funcionais (polimorfismos) do receptor adrenérgico beta2 vêm sendo associadas a diferentes estados funcionais do receptor e a diversos fenótipos cardiovasculares. Investigamos em 218 de jovens normotensos (entre 18 a 30 anos) a associação dos polimorfismos do receptor adrenérgico beta2 tipo Gln27Glu (Gln/Gln, Gln/Glu e Glu/Glu) e tipo Arg16Gly (Arg/Arg, Arg/Gly e Gly/Gly) com o perfil antropométrico e com os fenótipos cardiovasculares: o balanço autonômico para o coração (análise da VFC), a noradrenalina sérica, e variáveis hemodinâmicas, que foram registradas durante o repouso (5min) e o tilt test (teste de estresse postural, 5 min). Resultados: polimorfismo beta2 tipo Gln27Glu - comparados aos portadores do genótipo Gln/Gln, os indivíduos com genótipos Glu/Glu e Gln/Glu apresentaram uma menor relação cintura/quadril (p=0,008) e uma maior atividade simpática em resposta ao tilt teste, ou seja, maior aumento do componente LF (p=0,027) e maior relação LF/HF (p=0,014); polimorfismos beta2 tipo Arg16Gly - portadores do genótipo Arg/Arg apresentaram maior queda do índice alfa durante o tilt test, comparados aos outros genótipos; associação de polimorfismos (haplótipos) - portadores do haplótipo Gln27Gln/Arg16Gly apresentaram maior incremento da FC quando comparados aos portadores dos haplótipos Gln27Gln/Gly16Gly (p=0,06). Conclusão: foi possível detectar que os polimorfismos do receptor adrenérgico beta2 tipo Gln27Glu e tipo Arg16Gly têm impacto sobre o balanço autonômico cardíaco, respectivamente, aumentando a atividade simpática para o coração e diminuindo a atividade baroreflexa durante manobra de estresse postural, em indivíduos jovens normotensos / The autonomic nervous system (NS) has a pivotal role in cardiovascular control. Time domain and spectral analyzes of heart rate variability (HRV) indicates cardiac autonomic modulation, since it reflects the sympathetic (adrenergic receptors) and parasympathetic (muscarinic receptors) nerve activity over the Sinoatrial Node. Polymorphisms of the adrenergic receptor beta2 have been associated to different functional state of receptor and cardiovascular phenotypes. We analyzed in 218 young normotensive subjects (18-30 years old) the association of polymorphisms of the adrenergic receptor type Gln27Glu (Gln/Gln, Gln/Glu e Glu/Glu) and type Arg16Gly (Arg/Arg, Arg/Gly e Gly/Gly) with anthropometric data and cardiovascular phenotypes: cardiac autonomic balance (HRV), norephinefrine levels, and hemodynamic parameters, which were registered during rest (5min) and tilt test (5 min). Results: beta2 polymorphism type Gln27Glu - compared to subjects with genotype Gln/Gln, subjects with genotype Glu/Glu e Gln/Glu showed a lower WHR (p=0,008) and a higher increase in sympathetic activity during tilt teste, i.e., a higher increase in LF component (p=0,027) and LF/HF relation (p=0,014); beta2 polymorphism type Arg16Gly - subjects with genotype Arg/Arg demonstrated a higher decrease in alpha index during tilt test, compared to other genotypes; polymorphism association (haplotype) - subjects with Gln27Gln/Arg16Gly had a higher increase in hear rate compared to subjects with haplotype Gln27Gln/Gly16Gly (p=0,06). Conclusion: it was possible to detect in young normotensive subjects that polymorphisms of the adrenergic receptor type Gln27Glu and type Arg16Gly have an impact over cardiac autonomic balance, respectively, increasing the cardiac sympathetic activity and decreasing the baroreflex sensibility during tilt test

Durante situações aversivas, como choque nas patas, imobilidade ou restrição dos movimentos, há um aumento nos níveis de acetilcolina no hipocampo de ratos. Além disso, o aumento desse neurotransmissor está envolvido com a modulação comportamental do MCC, principalmente em sua porção dorsal, HD. Diante disso, é proposto neste estudo que os receptores muscarínicos presentes no HD de ratos, modulam a expressão da REC, no modelo do MCC. Ratos wistar foram submetidos às sessões de condicionamento aversivo contextual, sendo divididos nos grupos: condicionado (6 choques de 3s; 1,5 mA) e não condicionado (sem choques) . Quarenta e oito horas após esta sessão foram avaliadas a comportamental (congelamento) e respostas autonômicas (PAM, FC e queda da TC). Além disso, foi verificada a distribuição de receptores M1 e M3 nas subáreas do HD e a quantificação dos mesmos em animais condicionados, não condicionados e naive, 48 após a sessão de condicionamento. A microinjeção bilateral de hemicolínio, inibidor da captação de colina, no HD promoveu uma redução do tempo de congelamento durante a reexposição ao contexto aversivo, caracterizando um efeito do tipo ansiolítico. Além disso, este tratamento inibiu o aumento da PAM, FC e a queda da TC induzidos pelo MCC. O mesmo ocorreu com a administração de atropina, antagonista não seletivo de receptores muscarínicos, de forma dose-dependente em todas as respostas observadas. Adicionalmente, a microinjeção de diferentes doses de J104129 fumarate bloquearam o tempo de congelamento (de forma dose-dependente, semelhante a atropina), a elevação da PAM, FC e a queda da TC durante a re-exposição ao contexto aversivo. Como o J104129 fumarate bloqueia receptores muscarínicos tanto M1 quanto M3, foi utilizado um antagonista de maior afinidade para receptores do tipo M1, pirenzepina. Todas as doses utilizadas de pirenzepina inibiram as respostas autonômicas, sem afetar o tempo de congelamento induzidos pelo MCC. A análise de imunofluorescência, por duplamarcação, mostrou que receptores M1 e M3 estão distribuídos nos mesmos compartimentos celulares nas subáreas do HD. A quantificação dos receptores 48 horas após o condicionamento evidencia apenas o aumento de receptores M3 no hipocampo de ratos, sem alteração na população de receptores M1. Com este conjunto de resultados podemos concluir que a ACh no HD é essencial para a expressão da REC. Especificamente, eles sugerem que os receptores muscarínicos do tipo M1 presentes nesta estrutura estão envolvidos com as respostas autonômicas e somente os receptores M3 participam das respostas comportamentais. / During aversive and stressful situations, such as footshock, stillness and restriction of movements, there is an increase in the levels of acetylcholine in rat hippocampus. Moreover, the increasing in the synaptic level of this neurotransmitter is involved with behavioral modulation of contextual fear conditioning (CFC), especially in the dorsal portion, DH. Therefore, this study investigated the involvement of muscarinic receptors in DH of rats in the expression of conditioned emotional response (CER) in the CFC. Moreover, we verified the expression of these receptors in the DH by double labeling immunofluorescence. Male Wistar rats were subjected to aversive contextual conditioning sessions and were divided into two groups: conditioned and unconditioned. Forty-eight hours after this session were evaluated autonomic (mean arterial pressure, MAP, heart rate, HR and tail temperature, TT) and behavioral (freezing) responses. Moreover, the distribution of M1/M3 receptors in subareas of DH was observed and the quantification of these receptors were performed 48 hours after the conditioning session in conditioned, unconditioned and naive animals. The bilateral microinjection of hemicholinium, inhibitor of choline reuptake, in DH, caused a decrease of freezing during re-exposure to the aversive context, featuring an anxiolytic-like effect. Furthermore, this treatment inhibited the increase in MAP, HR and TT drop by CFC. DH muscarinic receptors antagonism evoked by atropine, a non-selective muscarinic antagonist, reduced the freezing, in a dose-dependent manner. Similar reduction was observed in autonomic responses. The selective antagonism of M1/M3 receptors evoked by J104129 fumarate also reduced freezing, in a dose-dependent manner, when compared with control animals. The same effect was observed with autonomic responses in all the tested doses. As J104129 fumarate blocks both M1 muscarinic as M3 muscarinic, was used a higher-affinity M1 antagonist, pirenzepine. All doses inhibited cardiovascular responses and decrease the TT drop, without affecting the freezing induced by CFC. The immunofluorescence analysis revealed that M1 and M3 receptors are distributed in the same cellular compartments in DH. The quantification of receptors showed an increase of M3 receptors in rat hippocampus, while no change in the density of receptors M1 was detected. These findings support that cholinergic neurotransmission present in DH is involved with the expression of responses evoked by fear contextual conditioning, through muscarinic receptors activation. In particular, M3 muscarinic receptors modulate behavioral responses, M1 and M3 muscarinic receptors modulate the autonomic responses.

Cholinergic input to, and cholinergic mechanisms within the lower lumbar (L6) and upper sacral (S1) spinal cord of rat may influence neuronal excitability and afferent transmission (Thor et al, 2000) and may provide the environment necessary for appropriate central nervous system control of bladder and bowel function. It is unclear, however, if cholinergic terminals and receptors are present in the L6 & S1 spinal segments of rat and when this may develop. Cholinergic mechanisms have been shown to alter sensory afferent transmission, enhance motoneuron excitability, induce plateau potentials via non-linear membrane properties in motoneurons and reveal oscillations in locomotor-related interneurons. The enhanced activity of sphincter motoneurons was attributed to non-linear properties during the continence phase of distention-evoked voiding in the decerebrate cat (Paroschy & Shefchyk, 2000). Candidate neurotransmitters inducing non-linear properties in cat sphincter motoneurons are 5-HT (Paroschy & Shefchyk, 2000) and acetylcholine via motoneuron axon collaterals (Sasaki, 1994) and other spinal sources. We have established using the antibody to the vesicular acetylcholine transporter (VAChT) that cholinergic terminals are present on ventrolateral Onuf (VLO), dorsomedial Onuf (DMO) motoneurons and parasympathetic preganglionic motoneurons (PGN) in the L6 and S1 rat spinal cord segments. Muscarinic receptor (M2), nicotinic-α4 and α7 receptor subunit immunoreactivity was also present on Onuf motoneurons and in regions dorsal to the PGN. One source of the cholinergic puncta on Onuf motoneurons may be from motoneuron axon collaterals which we observed on a postnatal day 15 VLO motoneuron. Cholinergic terminals were observed on vasoactive intestinal polypeptide-immunoreactive (VIP) afferents, interneurons in the intermediolateral (IML) region and perhaps on other afferents in the lateral and medial collateral pathway of L6 and S1 spinal segments. In the ventral horn, the cholinergic puncta and receptors appear to have a mature distribution around two weeks postnatal and the cholinergic terminals appeared to have a mature distribution in the IML region by three weeks postnatal. Using whole cell patch clamp recording techniques and thick slices of the L6 and S1 rat spinal cord, we observed excitatory responses of ventral horn neurons and motoneurons to carbachol (10-50 μM), a non-specific cholinergic agonist. Ventral horn neurons (postnatal day 8- 16) exhibited prolonged firing and prolonged depolarizations (plateau potentials) beyond the duration of the applied excitatory input from cholinergic (n=6/33) and other (n= 4/37) neurotransmitter systems. In a selection of the neurons with plateau potentials, the L-type calcium current played a role in the plateau production (n=5/5) and low frequency oscillations (n=2/2) as revealed by nifedipine. Postnatally, the voiding reflex changes from a perineal-evoked reflex, to the adult bladder-bladder reflex. Cholinergic input may be responsible in part for the bursting activity of the external urethral sphincter and the activation of the bladder, which is required for complete voiding reflexes in the adult rat. Plateau potentials and enhanced excitability due to cholinergic mechanisms could render inessential a constant excitatory drive that is required in the perineal-evoked voiding reflex in the neonatal rat and may underlie changes in the voiding reflexes that occur during postnatal development. / February 2006

The notion that learning and memory processes are highly dependent on central cholinergic neurotransmission has been widely accepted. However, studies documenting the importance of Acetylcholine (ACh) in attention have led some to suggest that attention impairments may underlie the deficits in learning and memory resulting from cholinergic disruptions. Using a visual discrimination task, I attempted to discern whether performance impairments by Scopolamine were predominantly due to the importance of muscarinic receptor integrity in attention, or memory consolidation in learning. Rats were trained in a visual discrimination task using a Y-shaped water maze apparatus. To successfully navigate to a hidden platform located in one of the two goal arms, rats learned to discriminate between 2 distinct visual cues, indicating the platform’s presence (CS+) or absence (CS-), respectively. Following task acquisition, testing continued using a combination of Regular trials (RT; both CS+ and CS- present) and Probe trials (PT; only one of the cues present). Results indicated that performance on PT was impaired due to greater task difficulty under conditions of reduced information, while Scopolamine (1 mg/kg) further impacted PT performance without affecting RTs. In a second experiment, PTs were administered with the platform present to provide reinforcement and a learning opportunity. Animals still exhibited poorer PT performance, but rapidly learned to rely on a single cue for accurate platform localization. Interestingly, this learning was not apparent under conditions of Scopolamine treatment (1 mg/kg), even though RT performance was completely unaffected. To examine experience-dependent changes in neuronal responding after visual discrimination learning, a subset of animals were anesthetised and visual evoked potentials (VEPs) in V1 and area CA1 of the hippocampus were recorded in response to CS+, CS-, and novel stimuli. In both the V1 and CA1, the VEP amplitudes elicited to familiar and novel stimuli were not significantly different. First, these experiments demonstrate the importance of the cholinergic system in sustaining visual attention and acquiring a new single-cue strategy. Furthermore, the null electrophysiology findings do not rule out the plastic response properties of the mature V1 and CA1, but remind us of the complex nature of memory encoding in the brain. / Thesis (Master, Psychology) -- Queen's University, 2011-09-16 13:50:24.045

Cholinergic input to, and cholinergic mechanisms within the lower lumbar (L6) and upper sacral (S1) spinal cord of rat may influence neuronal excitability and afferent transmission (Thor et al, 2000) and may provide the environment necessary for appropriate central nervous system control of bladder and bowel function. It is unclear, however, if cholinergic terminals and receptors are present in the L6 & S1 spinal segments of rat and when this may develop. Cholinergic mechanisms have been shown to alter sensory afferent transmission, enhance motoneuron excitability, induce plateau potentials via non-linear membrane properties in motoneurons and reveal oscillations in locomotor-related interneurons. The enhanced activity of sphincter motoneurons was attributed to non-linear properties during the continence phase of distention-evoked voiding in the decerebrate cat (Paroschy & Shefchyk, 2000). Candidate neurotransmitters inducing non-linear properties in cat sphincter motoneurons are 5-HT (Paroschy & Shefchyk, 2000) and acetylcholine via motoneuron axon collaterals (Sasaki, 1994) and other spinal sources. We have established using the antibody to the vesicular acetylcholine transporter (VAChT) that cholinergic terminals are present on ventrolateral Onuf (VLO), dorsomedial Onuf (DMO) motoneurons and parasympathetic preganglionic motoneurons (PGN) in the L6 and S1 rat spinal cord segments. Muscarinic receptor (M2), nicotinic-α4 and α7 receptor subunit immunoreactivity was also present on Onuf motoneurons and in regions dorsal to the PGN. One source of the cholinergic puncta on Onuf motoneurons may be from motoneuron axon collaterals which we observed on a postnatal day 15 VLO motoneuron. Cholinergic terminals were observed on vasoactive intestinal polypeptide-immunoreactive (VIP) afferents, interneurons in the intermediolateral (IML) region and perhaps on other afferents in the lateral and medial collateral pathway of L6 and S1 spinal segments. In the ventral horn, the cholinergic puncta and receptors appear to have a mature distribution around two weeks postnatal and the cholinergic terminals appeared to have a mature distribution in the IML region by three weeks postnatal. Using whole cell patch clamp recording techniques and thick slices of the L6 and S1 rat spinal cord, we observed excitatory responses of ventral horn neurons and motoneurons to carbachol (10-50 μM), a non-specific cholinergic agonist. Ventral horn neurons (postnatal day 8- 16) exhibited prolonged firing and prolonged depolarizations (plateau potentials) beyond the duration of the applied excitatory input from cholinergic (n=6/33) and other (n= 4/37) neurotransmitter systems. In a selection of the neurons with plateau potentials, the L-type calcium current played a role in the plateau production (n=5/5) and low frequency oscillations (n=2/2) as revealed by nifedipine. Postnatally, the voiding reflex changes from a perineal-evoked reflex, to the adult bladder-bladder reflex. Cholinergic input may be responsible in part for the bursting activity of the external urethral sphincter and the activation of the bladder, which is required for complete voiding reflexes in the adult rat. Plateau potentials and enhanced excitability due to cholinergic mechanisms could render inessential a constant excitatory drive that is required in the perineal-evoked voiding reflex in the neonatal rat and may underlie changes in the voiding reflexes that occur during postnatal development.

Cholinergic input to, and cholinergic mechanisms within the lower lumbar (L6) and upper sacral (S1) spinal cord of rat may influence neuronal excitability and afferent transmission (Thor et al, 2000) and may provide the environment necessary for appropriate central nervous system control of bladder and bowel function. It is unclear, however, if cholinergic terminals and receptors are present in the L6 & S1 spinal segments of rat and when this may develop. Cholinergic mechanisms have been shown to alter sensory afferent transmission, enhance motoneuron excitability, induce plateau potentials via non-linear membrane properties in motoneurons and reveal oscillations in locomotor-related interneurons. The enhanced activity of sphincter motoneurons was attributed to non-linear properties during the continence phase of distention-evoked voiding in the decerebrate cat (Paroschy & Shefchyk, 2000). Candidate neurotransmitters inducing non-linear properties in cat sphincter motoneurons are 5-HT (Paroschy & Shefchyk, 2000) and acetylcholine via motoneuron axon collaterals (Sasaki, 1994) and other spinal sources. We have established using the antibody to the vesicular acetylcholine transporter (VAChT) that cholinergic terminals are present on ventrolateral Onuf (VLO), dorsomedial Onuf (DMO) motoneurons and parasympathetic preganglionic motoneurons (PGN) in the L6 and S1 rat spinal cord segments. Muscarinic receptor (M2), nicotinic-α4 and α7 receptor subunit immunoreactivity was also present on Onuf motoneurons and in regions dorsal to the PGN. One source of the cholinergic puncta on Onuf motoneurons may be from motoneuron axon collaterals which we observed on a postnatal day 15 VLO motoneuron. Cholinergic terminals were observed on vasoactive intestinal polypeptide-immunoreactive (VIP) afferents, interneurons in the intermediolateral (IML) region and perhaps on other afferents in the lateral and medial collateral pathway of L6 and S1 spinal segments. In the ventral horn, the cholinergic puncta and receptors appear to have a mature distribution around two weeks postnatal and the cholinergic terminals appeared to have a mature distribution in the IML region by three weeks postnatal. Using whole cell patch clamp recording techniques and thick slices of the L6 and S1 rat spinal cord, we observed excitatory responses of ventral horn neurons and motoneurons to carbachol (10-50 μM), a non-specific cholinergic agonist. Ventral horn neurons (postnatal day 8- 16) exhibited prolonged firing and prolonged depolarizations (plateau potentials) beyond the duration of the applied excitatory input from cholinergic (n=6/33) and other (n= 4/37) neurotransmitter systems. In a selection of the neurons with plateau potentials, the L-type calcium current played a role in the plateau production (n=5/5) and low frequency oscillations (n=2/2) as revealed by nifedipine. Postnatally, the voiding reflex changes from a perineal-evoked reflex, to the adult bladder-bladder reflex. Cholinergic input may be responsible in part for the bursting activity of the external urethral sphincter and the activation of the bladder, which is required for complete voiding reflexes in the adult rat. Plateau potentials and enhanced excitability due to cholinergic mechanisms could render inessential a constant excitatory drive that is required in the perineal-evoked voiding reflex in the neonatal rat and may underlie changes in the voiding reflexes that occur during postnatal development.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2018-01-30T17:09:56Z No. of bitstreams: 1 DissAA.pdf: 1196078 bytes, checksum: c96629c7fdc72285ebf9260f9394bbae (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-02-01T17:39:56Z (GMT) No. of bitstreams: 1 DissAA.pdf: 1196078 bytes, checksum: c96629c7fdc72285ebf9260f9394bbae (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-02-01T17:40:05Z (GMT) No. of bitstreams: 1 DissAA.pdf: 1196078 bytes, checksum: c96629c7fdc72285ebf9260f9394bbae (MD5) / Made available in DSpace on 2018-02-01T17:44:38Z (GMT). No. of bitstreams: 1 DissAA.pdf: 1196078 bytes, checksum: c96629c7fdc72285ebf9260f9394bbae (MD5) Previous issue date: 2017-07-10 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Water and sodium intake are fundamental behaviors for body fluid homeostasis. These behaviors are controlled by a neural circuitry involving facilitatory and inhibitory mechanisms, which are modulated by signals activated by changes in body fluid volume and composition. Important inhibitory mechanisms for water intake and particularly for sodium intake are located in the lateral parabrachial nucleus (LPBN), a pontine structure. It is known that LPBN inhibitory mechanisms are controlled by several neurotransmitters, some increasing, others reducing the action of this nucleus on sodium intake... / A ingestão de água e a ingestão de sódio são comportamentos fundamentais para a homeostase dos líquidos corporais. A manifestação destes comportamentos é controlada por um circuito neural constituído por mecanismos facilitatórios e inibitórios os quais são constantemente modulados por informações relativas aos líquidos corporais. Importantes mecanismos inibitórios para a ingestão de água e especialmente para a ingestão de sódio localizam-se no núcleo parabraquial lateral (NPBL), uma estrutura pontina. Sabe-se que os mecanismos inibitórios do NPBL são controlados por diversos neurotransmissores, alguns aumentando e outros diminuindo a ação deste núcleo sobre a ingestão de sódio .....

The aim of this thesis was to clarify the influence of the stress on the adrenergic and muscarinic receptors in the heart and in the lungs. Research was perform on rat hearts and lungs and on the hearts and lungs of the CRH KO mice. First, we assessed mRNA levels of all α- and β-adrenergic receptor and muscarinic receptor subtypes. Subsequently, we performed the radioligand-binding studies to determine densities of these receptors. We identified all three α1-adrenergic receptor subtypes in the rat lungs. In the lungs of WT mice, we found that the amount of α1-adrenergic and muscarinic receptors was sex-dependent. Densities of the former were higher in females and those of the latter were higher in males. There was no difference between males and females in β-adrenergic receptor density. As for CRH KO mice, the basal densities of studied receptors were lower than in CRH WT mice (except β1-adrenergic receptors in females). The main purpose of the thesis was to detect the immobilization-induced changes in the studied receptors in the kontrol (WT) and CRH KO mice. Short-term and long-term immobilization caused decrease in all α1-adrenergic receptor subtypes in females, whereas only α1A-adrenergic receptors decreased in males. The amount of β1-adrenergic receptors decreased in males and remained without...