scholarly journals Effect of Manganese Chloride on the Neurochemical Profile of the Rat Hypothalamus

2011 ◽  
Vol 31 (12) ◽  
pp. 2324-2333 ◽  
Author(s):  
Nathalie Just ◽  
Cristina Cudalbu ◽  
Hongxia Lei ◽  
Rolf Gruetter

Manganese (Mn2+)-enhanced magnetic resonance imaging studies of the neuronal pathways of the hypothalamus showed that information about the regulation of food intake and energy balance circulate through specific hypothalamic nuclei. The dehydration-induced anorexia (DIA) model demonstrated to be appropriate for studying the hypothalamus with Mn2+-enhanced magnetic resonance imaging. Manganese is involved in the normal functioning of a variety of physiological processes and is associated with enzymes contributing to neurotransmitter synthesis and metabolism. It also induces psychiatric and motor disturbances. The molecular mechanisms by which Mn2+ produces alterations of the hypothalamic physiological processes are not well understood. 1H-magnetic resonance spectroscopy measurements of the rodent hypothalamus are challenging due to the distant location of the hypothalamus resulting in limited measurement sensitivity. The present study proposed to investigate the effects of Mn2+ on the neurochemical profile of the hypothalamus in normal, DIA, and overnight fasted female rats at 14.1 T. Results provide evidence that γ-aminobutyric acid has an essential role in the maintenance of energy homeostasis in the hypothalamus but is not condition specific. On the contrary, glutamine, glutamate, and taurine appear to respond more accurately to Mn2+ exposure. An increase in glutamine levels could also be a characteristic response of the hypothalamus to DIA.

2020 ◽  
Author(s):  
Jia-Xiang Xin ◽  
Yi Li ◽  
Hui-Xia Liu ◽  
Jianqi Li ◽  
Guang Yang ◽  
...  

ABSTRACTMagnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) have tremendous utility in many fields, such as clinical diagnosis, medical research and brain science. MRI provides high resolution anatomic images of tissues/organs, and MRS provides functional molecular information related to specific regions of tissues/organs. However, it is often difficult for conventional MRI/MRS to selectively image/probe a specific metabolite molecule other than water and fat. This greatly limits study of the molecular mechanisms underlying metabolism and disease. Herein, we report a novel method for obtaining an exact molecularly targeted MRI and MRS. This method uses the nuclear spin singlet state to select the signals from a specific molecule. Several endogenous molecules in living organism such as N-acetylaspartate and dopamine have been exemplarily imaged and probed as the targeted molecules in the MRI and MRS experiments, demonstrating the unique molecular selectivity of the developed method.Endogenous-molecule-targeted MRI and MRS can be achieved by using the new pulse sequences


2015 ◽  
Vol 8 (3) ◽  
pp. 113-117 ◽  
Author(s):  
Petr N. Menshanov ◽  
Andrey E. Akulov

Abstract In vivo study of cerebral metabolism in neonatal animals by high-resolution magnetic resonance spectroscopy (MRS) is an important tool for deciphering the developmental origins of adult diseases. Up to date, all in vivo spectrum acquisition procedures have been performed in neonatal rodents under anesthesia. However, it is still unknown if the inhaled anesthetic isoflurane, which is commonly used in magnetic resonance imaging studies, could affect metabolite levels in the brain of neonatal rats. Moreover, the unanesthetized MRS preparation that uses neonatal rodent pups is still lacking. Here, a novel restraint protocol was developed for neonatal rats in accordance with the European Directive 2010/63/EU. This protocol shares the same gradation of severity as the protocol for non-invasive magnetic resonance imaging of animals with appropriate sedation or anesthesia. Such immobilization of neonatal rats without anesthesia can be implemented for MRS studies when an interaction between anesthetic and target drugs is expected. Short-term isoflurane treatment did not affect the levels of key metabolites in the hippocampi of anesthetized pups and, in contrast to juvenile and adult rodents, it is suitable for MRS studies in neonatal rats when the interaction between anesthetic and target drugs is not expected.


2005 ◽  
Vol 2 (2) ◽  
pp. 133-140 ◽  
Author(s):  
D. Mietchen ◽  
H. Keupp ◽  
B. Manz ◽  
F. Volke

Abstract. For more than a decade, Magnetic Resonance Imaging (MRI) has been routinely employed in clinical diagnostics because it allows non-invasive studies of anatomical structures and physiological processes in vivo and to differentiate between healthy and pathological states, particularly of soft tissue. Here, we demonstrate that MRI can likewise be applied to fossilized biological samples and help in elucidating paleopathological and paleoecological questions: Five anomalous guards of Jurassic and Cretaceous belemnites are presented along with putative paleopathological diagnoses directly derived from 3D MR images with microscopic resolution. Syn vivo deformities of both the mineralized internal rostrum and the surrounding former soft tissue can be traced back in part to traumatic events of predator-prey-interactions, and partly to parasitism. Besides, evidence is presented that the frequently observed anomalous apical collar might be indicative of an inflammatory disease. These findings highlight the potential of Magnetic Resonance techniques for further paleontological applications.


2017 ◽  
Author(s):  
Joshua P Klein

Modern neuroimaging has revolutionized the practice of neurology by allowing visualization and monitoring of evolving pathophysiologic processes. High-resolution magnetic resonance imaging (MRI) can now resolve structural abnormalities on a near-cellular level. Advances in functional imaging can assess the in vivo metabolic, vascular, and functional states of neuronal and glial populations in real time. Given the high density of data obtained from neuroimaging studies, it is essential for the clinician to take an active role in understanding the nature and significance of imaging abnormalities. This chapter reviews computed tomography and MRI techniques (including angiography and advanced sequences), specialized protocols for investigating specific diagnoses, risks associated with imaging, disease-specific imaging findings with general strategies for interpretation, and incidental findings and artifacts. Figures include computed tomography, T1- and T2-weighted signal intensity, diffusion-weighted magnetic resonance imaging, magnetic resonance spectroscopy, imaging in epilepsy and dementia, extra-axial versus intra-axial lesions, typical lesions of multiple sclerosis, spinal imaging, spinal pathology, vascular pathology, intracranial hemorrhage, and common imaging artifacts. Tables list Hounsfield units, patterns of enhancement from imaging, advanced techniques in imaging, magnetic resonance imaging sequences, and the evolution of cerebral infarction and intraparenchymal hemorrhage on magnetic resonance imaging. This review contains 12 figures, 6 tables, and 213 references.


2021 ◽  
Vol 15 (9) ◽  
pp. 4009-4011
Author(s):  
Saulat Sarfraz ◽  
Mahwish Farzana

Background: In spite of recent advances in the use of diagnostic imaging modalities none of them has a hundred percent accuracy. So, misdiagnosis still occurs. Many trials are being done to evaluate the accuracy of these tools individually or in combination. The most useful investigation is MRI which broadly gives information of lesion as well its relationship with surrounding structures. While magnetic resonance spectroscopy further characterizes the lesion into benign or malignant. So this study is bit superior giving more details. By enlarge histopathology is gold standard for ultimate diagnosis. However these radiological investigations are extremely important for preoperative planning as well management of the lesion. In this study we compare the diagnostic accuracy of Magnetic Resonance Spectroscopy (MRS) with conventional MRI (Magnetic Resonance Imaging) sequences for diagnosis of brain tumors keeping histopathology as gold standard. Methods: The study was performed in 150 clinically suspected cases which were referred to Radiology Department from OPD, Indoor, Emergency and private sources from outside the hospital. Results: Majority 85(56.7%) were adult males and 65(43.3%) were adult females. The study was divided into two major age groups. There were 33cases (22%) with average age 20-35 years. The other age group 36-50 years had 40(26.7%) Majority of the cases 77(51.3%) were of average >50 years of age. The higher age groups showed a female dominance. Histopathology of 100(66.7%) cases confirmed positive and 50(33.3%) negative for MR Spectroscopy. On comparison of conventional MRI with contrast, and Histopathology it was observed that the sensitivity of MRI was 74.0% and the specificity 82.0%.The positive and negative predictive values gave a lower accuracy rate of 76.6%. Conclusion: The conclusion of our study is that MRS is a rigorous, non-invasive, safe and convenient imaging modality for the evaluation of brain tumors as compared to MRI. Keywords: Brain tumors, MRI, MRS, Histopathology


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