Global ETD Search

31	Pharmaceutical and Natural (Exercise) Mechanisms to Mitigate the Negative Impact of PTSD and Chronic Stress on Synaptic Plasticity and Memory Miller, Roxanne M 01 November 2017 (has links) Synapses can be altered due to experiences in a process called synaptic plasticity, which causes memory formations. Synapses can be strengthened through methods known as long-term potentiation (LTP) or weakened through long-term depression (LTD). Stresses can cause changes by altering synapses through either LTP or LTD. Rats were used to study the effects of post-traumatic stress disorder (PTSD)-like symptoms and a prophylactic treatment using pharmaceuticals. The first model used was the single prolonged stress (SPS) with two weeks of chronic light, which was not as effective for causing changes in synaptic plasticity. The second model, seven days of social defeat (SD) with two weeks of chronic light was more effective at inducing PTSD-like behavior symptoms and causing changes in LTP levels in the ventral hippocampus, amygdala, and prefrontal cortex between stressed and non-stressed rats. For the prophylactic treatment, propranolol and mifepristone were administered one week prior to and throughout the two weeks of the social defeat protocol. The drugs were able to prevent the changes due to stress on LTP in the three aforementioned brain regions, but did not change the anxious behavior of the rats. An enzyme-linked immunosorbent assay (ELISA) was used to determine corticosterone and norepinephrine levels between the different groups of rats. No significant differences were detected between SD and control rats, but SD injected rats were different from controls indicating that the injections were causing added stress. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was used to detect changes in the adrenergic, corticoid, AMPA, and NMDA receptors. There were a few significant changes to some of the targets indicating that the stress protocol and drugs were having an effect on the mRNA expression. Propranolol and mifepristone could possibly be used as a prophylactic treatment for traumatic stress. In a separate study, techniques were used to determine the negative effects chronic stress (non-PTSD-like) has on synaptic plasticity in the dorsal hippocampus and to show how exercise was able to mitigate some of those negative stress effects. Electrophysiology showed differences in LTP between four groups of mice: sedentary no stress (SNS), sedentary with stress (SWS), exercise with stress (EWS), and exercise no stress (ENS). SWS had the lowest amount of LTP, whereas ENS had the highest. SNS and EWS had similar levels of LTP, which were in between the SWS and ENS groups. Corticosterone blood levels measured by an ELISA showed significant increases in the stressed groups compared to the non-stressed groups. The radial arm maze showed that both groups of exercise mice made fewer reference memory errors the second week of testing compared to the sedentary groups. RT-qPCR determined that brain-derived neurotrophic factor (BDNF) and corticoid and dopamine 5 receptors were likely causing some of the memory changes. chronic stress LTP LTD corticoid receptor dopamine receptor adrenergic receptor exercise propranolol mifepristone BDNF hippocampus amygdala prefrontal cortex Life Sciences Physiology
32	Pharmaceutical and Natural (Exercise) Mechanisms to Mitigate the Negative Impact of PTSD and Chronic Stress on Synaptic Plasticity and Memory Miller, Roxanne M 01 November 2017 (has links) Synapses can be altered due to experiences in a process called synaptic plasticity, which causes memory formations. Synapses can be strengthened through methods known as long-term potentiation (LTP) or weakened through long-term depression (LTD). Stresses can cause changes by altering synapses through either LTP or LTD. Rats were used to study the effects of post-traumatic stress disorder (PTSD)-like symptoms and a prophylactic treatment using pharmaceuticals. The first model used was the single prolonged stress (SPS) with two weeks of chronic light, which was not as effective for causing changes in synaptic plasticity. The second model, seven days of social defeat (SD) with two weeks of chronic light was more effective at inducing PTSD-like behavior symptoms and causing changes in LTP levels in the ventral hippocampus, amygdala, and prefrontal cortex between stressed and non-stressed rats. For the prophylactic treatment, propranolol and mifepristone were administered one week prior to and throughout the two weeks of the social defeat protocol. The drugs were able to prevent the changes due to stress on LTP in the three aforementioned brain regions, but did not change the anxious behavior of the rats. An enzyme-linked immunosorbent assay (ELISA) was used to determine corticosterone and norepinephrine levels between the different groups of rats. No significant differences were detected between SD and control rats, but SD injected rats were different from controls indicating that the injections were causing added stress. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was used to detect changes in the adrenergic, corticoid, AMPA, and NMDA receptors. There were a few significant changes to some of the targets indicating that the stress protocol and drugs were having an effect on the mRNA expression. Propranolol and mifepristone could possibly be used as a prophylactic treatment for traumatic stress. In a separate study, techniques were used to determine the negative effects chronic stress (non-PTSD-like) has on synaptic plasticity in the dorsal hippocampus and to show how exercise was able to mitigate some of those negative stress effects. Electrophysiology showed differences in LTP between four groups of mice: sedentary no stress (SNS), sedentary with stress (SWS), exercise with stress (EWS), and exercise no stress (ENS). SWS had the lowest amount of LTP, whereas ENS had the highest. SNS and EWS had similar levels of LTP, which were in between the SWS and ENS groups. Corticosterone blood levels measured by an ELISA showed significant increases in the stressed groups compared to the non-stressed groups. The radial arm maze showed that both groups of exercise mice made fewer reference memory errors the second week of testing compared to the sedentary groups. RT-qPCR determined that brain-derived neurotrophic factor (BDNF) and corticoid and dopamine 5 receptors were likely causing some of the memory changes. chronic stress LTP LTD corticoid receptor dopamine receptor adrenergic receptor exercise propranolol mifepristone BDNF hippocampus amygdala prefrontal cortex Life Sciences Physiology
33	Quantitative dopamine imaging in humans using magnetic resonance and positron emission tomography Tziortzi, Andri January 2014 (has links) Dopamine is an important neurotransmitter that is involved in several human functions such as reward, cognition, emotions and movement. Abnormalities of the neurotransmitter itself, or the dopamine receptors through which it exerts its actions, contribute to a wide range of psychiatric and neurological disorders such as Parkinson’s disease and schizophrenia. Thus far, despite the great interest and extensive research, the exact role of dopamine and the causalities of dopamine related disorders are not fully understood. Here we have developed multimodal imaging methods, to investigate the release of dopamine and the distribution of the dopamine D2-like receptor family in-vivo in healthy humans. We use the [<sup>11</sup>C]PHNO PET ligand, which enables exploration of dopamine-related parameters in striatal regions, and for the first time in extrastriatal regions, that are known to be associated with distinctive functions and disorders. Our methods involve robust approaches for the manual and automated delineation of these brain regions, in terms of structural and functional organisation, using information from structural and diffusion MRI images. These data have been combined with [<sup>11</sup>C]PHNO PET data for quantitative dopamine imaging. Our investigation has revealed the distribution and the relative density of the D3R and D2R sites of the dopamine D2-like receptor family, in healthy humans. In addition, we have demonstrated that the release of dopamine has a functional rather than a structural specificity and that the relative densities of the D3R and D2R sites do not drive this specificity. We have also shown that the dopamine D3R receptor is primarily distributed in regions that have a central role in reward and addiction. A finding that supports theories that assigns a primarily limbic role to the D3R. 612.8042
34	Multiple Sklerose und Dopamin-Rezeptoren / Multiple sclerosis and dopamine receptors Schumacher, Jakob 13 April 2011 (has links) No description available. 610 Medizin, Gesundheit Medicine 44.90
35	Effect of Dopamine Receptor DRD2 and ANKK1 Polymorphisms on Dietary Compliance, Blood Pressure, and BMI in Type 2 Diabetic Patients Abdulnour, Shahad 14 December 2010 (has links) Reduction in dopamine receptor D2, has been associated with insufficient brain reward, food addiction, obesity, and type 2 diabetes (T2D). Our aim was to assess whether the genetic variability responsible for this reduction is associated with poor dietary compliance and life style habits in T2D patients. Genetic-analysis was done for 109 T2D individuals who completed a 24-week randomized clinical trial and were assigned to follow either a low-GI or a high-fibre diet. Polymorphisms of TaqIA and C957T were compared with physical and biochemical measures. Regardless of dietary treatments, individuals with the C957T-T allele and the TaqIA-A2 allele were significantly associated with blood pressure reduction. Carriers of the T allele significantly lowered their body mass index (BMI) over the 24-week trial. Our findings suggest that the presence of the TaqIA-A2 allele is associated with a decrease in blood pressure. The C957T-T allele was associated with decrease in pressure and body weight. dopamine receptor Glycemic Index DRD2 ANKK1 addiction diabetes BMI blood pressure dietary compliance reward obestiy weight genetic glucose C957T TaqIA polymorphism triglycerides cholesterol linkage disequilibrium DNA single nucleotide polymorphism HbA1c insulin resistance eating gene dopamine behaviour nutrition neuroscience Reward Deficiency Syndrome HDL LDL exercise fatty acid LOD neurogenetics 0369 0570 0317 0384
36	Effect of Dopamine Receptor DRD2 and ANKK1 Polymorphisms on Dietary Compliance, Blood Pressure, and BMI in Type 2 Diabetic Patients Abdulnour, Shahad 14 December 2010 (has links) Reduction in dopamine receptor D2, has been associated with insufficient brain reward, food addiction, obesity, and type 2 diabetes (T2D). Our aim was to assess whether the genetic variability responsible for this reduction is associated with poor dietary compliance and life style habits in T2D patients. Genetic-analysis was done for 109 T2D individuals who completed a 24-week randomized clinical trial and were assigned to follow either a low-GI or a high-fibre diet. Polymorphisms of TaqIA and C957T were compared with physical and biochemical measures. Regardless of dietary treatments, individuals with the C957T-T allele and the TaqIA-A2 allele were significantly associated with blood pressure reduction. Carriers of the T allele significantly lowered their body mass index (BMI) over the 24-week trial. Our findings suggest that the presence of the TaqIA-A2 allele is associated with a decrease in blood pressure. The C957T-T allele was associated with decrease in pressure and body weight. dopamine receptor Glycemic Index DRD2 ANKK1 addiction diabetes BMI blood pressure dietary compliance reward obestiy weight genetic glucose C957T TaqIA polymorphism triglycerides cholesterol linkage disequilibrium DNA single nucleotide polymorphism HbA1c insulin resistance eating gene dopamine behaviour nutrition neuroscience Reward Deficiency Syndrome HDL LDL exercise fatty acid LOD neurogenetics 0369 0570 0317 0384
37	電刺激大鼠側韁核對區辨性低頻操作式制約行為的影響 / The effects of electrical stimulation in the lateral habenula on operant behavior maintained by the differential reinforcement of low-rate (DRL) schedule of reinforcement in the rat 林禧岳 Unknown Date (has links) 透過神經科學的研究，對於大腦的行為功能已有一定的認識，不同於以往的認識，目前認為神經行為機制不只由單一腦區或單一神經化學系統所調控。深部大腦電刺激經常被用來研究特定腦區的行為功能。但是，深部大腦電刺激的作用機制仍然不清楚。最近幾年臨床研究發現，利用電刺激在側韁核成功的治療憂鬱症患者。然而，目前認為側韁核與多巴胺系統互為負回饋作用，共同參與在動機行為的酬賞反應中。本實驗室先前的研究顯示，破壞韁核造成區辨性低頻操作式制約行為 (簡稱DRL行為)學習的障礙，然而，電刺激在側韁核造成DRL行為表現的結果還是未知的。所以，本實驗主要以電刺激在側韁核觀察大鼠行為上的改變，探討側韁核在行為上參與的功能。實驗一的結果顯示電刺激在側韁核並不影響自發性運動能力，在不同電流強度的刺激下也不會影響。實驗二的結果顯示電刺激在側韁核造成DRL 15秒的行為有類安非他命效果之行為表現，在高頻率電刺激有較顯著類安非他命的效果。實驗三的結果顯示電刺激在側韁核造成DRL 15秒的行為之影響，會被多巴胺受體抑制劑所抵消，而單獨注射巴胺受體抑制劑並不影響DRL 15秒的行為。實驗四的結果顯示電刺激在側韁核造成DRL 15秒的行為之影響，不會被正腎上腺素受體抑制劑所抵消。實驗五的結果顯示電刺激在側韁核造成DRL 72秒的行為之影響並不如DRL 15秒的行為顯著。實驗六的結果顯示電刺激在側韁核並不會造成大鼠無法區辨酬賞的量。綜合而言，側韁核在動機行為的角色，是透過影響多巴胺系統造成行為的改變。 / Behavioral function of the brain has been studied in neuroscience and progressively accumulated informative data to reveal the neurobehavioral mechanisms. It is now realized that those underlying mechanisms of behaviors is not as such simple as previous thought of limiting only in one locus of the brain or solely by one neurochemical system. The deep brain stimulation is usually used to study the behavioral function of specific brain regions. However, the mechanism of the deep brain stimulation is still unclear. The previous study has shown that electrical stimulation of the lateral habenula (LHb) successfully treated depression symptoms in the patients. It is proposed that an inhibitory role of LHb on the mibrain dopamine (DA) system which mediates the reward-related behavior. A previous study of this lab showed that lesion of habenula impaired the acquisition of differential reinforcement of low-rate responding (DRL) behavior. But, the effect of LHb stimulation on the DRL behavior is still unclear. To determine the functions of LHb involving in the behavior, the electrical stimulation was applied in LHb to observe the behavioral change of rats. The results of Experiment 1 showed that the LHb stimulation had no effect on locomotor activity. In Experiment 2, the LHb stimulation was shown to affect DRL 15-s behavior, which effects were similar to those affected by amphetamine. Experiment 3 showed that the DA receptor antagonists reversed the effects of LHb stimulation, while experiment 4 showed that norepinephrine (NE) receptor antagonists had no reversal effect on DRL 15-s behavior. In Experiment 5, the amphetamine-like behavior induced by LHb stimulation had subtle effects on DRL 72-s behavior. Experiment 6 showed that the LHb stimulation had no effect on a discrimination task. These data suggest that the LHb modulating DRL behavior is DA-dependent. 深部大腦電刺激側韁核多巴胺受體抑制劑正腎上腺素受體抑制劑 deep brain stimulation lateral habenula dopamine receptor antagonists norepinephrine receptor antagonists

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