scholarly journals Whole Brain Mapping of Neurons Innervating Extraorbital Lacrimal Glands in Mice and Rats of Both Genders

2021 ◽  
Vol 15 ◽  
Author(s):  
Ying Zhai ◽  
Min Li ◽  
Zhu Gui ◽  
Yeli Wang ◽  
Ting Hu ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Pseudorabies Virus ◽  
Isotope Labeling ◽  
Female Rats ◽  
Structural Basis ◽  
Reticular Nucleus ◽  
Resonance Spectroscopy ◽  
Lacrimal Glands ◽  
Hypothalamic Area ◽  
Whole Brain

The extraorbital lacrimal glands (ELGs) secret tears to maintain a homeostatic environment for ocular surfaces, and pheromones to mediate social interactions. Although its distinct gender-related differences in mice and rats have been identified, its comprehensive histology together with whole-brain neuronal network remain largely unknown. The primary objective of the present study was to investigate whether sex-specific differences take place in histological and physiological perspectives. Morphological and histological data were obtained via magnetic resonance imaging (MRI), hematoxylin-eosin (HE) staining in mice and rats of both genders. The innervating network was visualized by a pseudorabies virus (PRV) mediated retrograde trans-multi-synaptic tracing system for adult C57BL6/J mice of both genders. In terms of ELGs' anatomy, mice and rats across genders both have 7 main lobes, with one exception observed in female rats which have only 5 lobes. Both female rats and mice generally have relatively smaller shape size, absolute weight, and cell size than males. Our viral tracing revealed a similar trend of innervating patterns antero-posteriorly, but significant gender differences were also observed in the hypothalamus (HY), olfactory areas (OLF), and striatum (STR). Brain regions including piriform area (Pir), post-piriform transition area (TR), central amygdalar nucleus (CEA), medial amygdalar nucleus (MEA), lateral hypothalamic area (LHA), parasubthalamic nucleus (PSTN), pontin reticular nucleus (caudal part) (PRNc), and parabrachial nucleus, (PB) were commonly labeled. In addition, chemical isotope labeling-assisted liquid chromatography-mass spectrometry (CIL-LC-MS) and nuclear magnetic resonance spectroscopy (NMR spectroscopy) were performed to reveal the fatty acids and metabolism of the ELGs, reflecting the relationship between pheromone secretion and brain network. Overall, our results revealed basic properties and the input neural networks for ELGs in both genders of mice, providing a structural basis to analyze the diverse functions of ELGs.

scholarly journals Relationship between depression, prefrontal creatine and grey matter volume

2021 ◽  
pp. 026988112110505
Author(s):  
Paul Faulkner ◽  
Susanna Lucini Paioni ◽  
Petya Kozhuharova ◽  
Natasza Orlov ◽  
David J Lythgoe ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Magnetic Resonance ◽  
Grey Matter ◽  
Well Being ◽  
Future Research ◽  
Resonance Spectroscopy ◽  
Grey Matter Volume ◽  
Whole Brain ◽  
Negatively Associated ◽  
Matter Volume

Background: Depression and low mood are leading contributors to disability worldwide. Research indicates that clinical depression may be associated with low creatine concentrations in the brain and low prefrontal grey matter volume. Because subclinical depression also contributes to difficulties in day-to-day life, understanding the neural mechanisms of depressive symptoms in all individuals, even at a subclinical level, may aid public health. Methods: Eighty-four young adult participants completed the Depression, Anxiety and Stress Scale (DASS) to quantify severity of depression, anxiety and stress, and underwent 1H-Magnetic Resonance Spectroscopy of the medial prefrontal cortex and structural magnetic resonance imaging (MRI) to determine whole-brain grey matter volume. Results/outcomes: DASS depression scores were negatively associated (a) with concentrations of creatine (but not other metabolites) in the prefrontal cortex and (b) with grey matter volume in the right superior medial frontal gyrus. Medial prefrontal creatine concentrations and right superior medial frontal grey matter volume were positively correlated. DASS anxiety and DASS stress scores were not related to prefrontal metabolite concentrations or whole-brain grey matter volume. Conclusions/interpretations: This study provides preliminary evidence from a representative group of individuals who exhibit a range of depression levels that prefrontal creatine and grey matter volume are negatively associated with depression. While future research is needed to fully understand this relationship, these results provide support for previous findings, which indicate that increasing creatine concentrations in the prefrontal cortex may improve mood and well-being.

scholarly journals Comparison of reproducibility of single voxel spectroscopy and whole-brain magnetic resonance spectroscopy imaging at 3T

2018 ◽  
Vol 31 (4) ◽  
pp. e3898 ◽  
Author(s):  
Yue Zhang ◽  
Edward Taub ◽  
Nouha Salibi ◽  
Gitendra Uswatte ◽  
Andrew A. Maudsley ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Whole Brain ◽  
Single Voxel ◽  
Magnetic Resonance Spectroscopy Imaging

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
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Energy Homeostasis ◽  
Molecular Mechanisms ◽  
Female Rats ◽  
Resonance Spectroscopy ◽  
Resonance Imaging ◽  
Measurement Sensitivity ◽  
Physiological Processes ◽  
Neurochemical Profile

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.

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