scholarly journals Circulating IGF1 regulates hippocampal IGF1 levels and brain gene expression during adolescence

2011 ◽  
Vol 211 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Han Yan ◽  
Matthew Mitschelen ◽  
Georgina V Bixler ◽  
Robert M Brucklacher ◽  
Julie A Farley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Growth ◽  
Somatic Growth ◽  
Brain Structures ◽  
Gh Treatment ◽  
Brain Gene Expression ◽  
Gh Replacement ◽  
Final Adult Height ◽  
And Function ◽  
The Brain

GH and its anabolic mediator, IGF1, are important not only in somatic growth but also in the regulation of brain function. Even though GH treatment has been used clinically to improve body composition and exercise capacity in adults, its influence on central nervous system function has only recently been recognized. This is also the case for children with childhood-onset GH deficiency (GHD) where GH has been used to stimulate bone growth and enhance final adult height. Circulating IGF1 is transported across the blood–brain barrier and IGF1 and its receptors are also synthesized in the brain by neurons and glial and endothelial cells. Nevertheless, the relationship between circulating IGF1 and brain IGF1 remains unclear. This study, using a GH-deficient dwarf rat model and peripheral GH replacement, investigated the effects of circulating IGF1 during adolescence on IGF1 levels in the brain. Our results demonstrated that hippocampal IGF1 protein concentrations during adolescence are highly regulated by circulating IGF1, which were reduced by GHD and restored by systematic GH replacement. Importantly, IGF1 levels in the cerebrospinal fluid were decreased by GHD but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF1 levels did not modify the transcription ofIgf1or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period.

35 Nicotinic receptors (nAChR) in the brain : Gene expression and contribution to learning and aging processes

1996 ◽  
Vol 17 (4) ◽  
pp. S9-S10
Author(s):  
Jean-Pierre Changeux ◽  
Alain Bessis ◽  
Marina Picciotto ◽  
Michele Zoli
Keyword(s):  
Gene Expression ◽  
Nicotinic Receptors ◽  
Brain Gene Expression ◽  
The Brain

scholarly journals Can exercise make our children smarter?

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Nenad Stojiljković ◽  
Petar Mitić ◽  
Goran Sporiš
Keyword(s):  
White Matter ◽  
Brain Structure ◽  
Methodological Approach ◽  
Brain Structures ◽  
Structure And Function ◽  
Healthy Children ◽  
Cross Sectional ◽  
Brain Structure And Function ◽  
And Function ◽  
The Brain

Purpose. The aim of this study is to reveal the effects of exercise on the brain structure and function in children, and to analyze methodological approach applied in the researches of this topic. Methods. This literature review provides an overview of important findings in this fast growing research domain. Results from cross-sectional, longitudinal, and interventional studies of the influence of exercise on the brain structure and function of healthy children are reviewed and discussed. Results. The majority of researches are done as cross sectional studies based on the exploring correlation between the level of physical activity and characteristics of brain structure and function. Results of the studies indicate that exercise has positive correlation with improved cognition and beneficial changes to brain function in children. Physically active children have greater white matter integrity in several white matter tracts (corpus callosum, corona radiata, and superior longitudinal fasciculus), have greater volume of gray matter in the hippocampus and basal ganglia than their physically inactive counterparts. The longitudinal/interventional studies also showed that exercise (mainly aerobic) improve cognitive performance of children and causes changes observed on functional magnetic resonance imaging scans (fMRI) located in prefrontal and parietal regions. Conclusion. Previous researches undoubtable proved that exercise can make positive changes of the brain structures in children, specifically the volume of the hippocampus which is the center of learning and memory. Finally the researchers agree that the most influential type of exercise on changes of brain structure and functions are the aerobic exercises. 

scholarly journals Tanycyte-independent control of hypothalamic leptin signaling

2019 ◽  
Author(s):  
Sooyeon Yoo ◽  
David Cha ◽  
Dong Won Kim ◽  
Thanh V. Hoang ◽  
Seth Blackshaw
Keyword(s):  
Gene Expression ◽  
Single Molecule ◽  
Leptin Receptor ◽  
Cell Types ◽  
Leptin Signaling ◽  
And Function ◽  
Induced Changes ◽  
The Brain ◽  
Specific Deletion

AbstractLeptin is secreted by adipocytes to regulate appetite and body weight. Recent studies have reported that tanycytes actively transport circulating leptin across the brain barrier into the hypothalamus, and are required for normal levels of hypothalamic leptin signaling. However, direct evidence for leptin receptor (LepR) expression is lacking, and the effect of tanycyte-specific deletion of LepR has not been investigated. In this study, we analyze the expression and function of the tanycytic LepR in mice. Using single-molecule fluorescent in situ hybridization (smfISH), RT-qPCR, single-cell RNA sequencing (scRNA-Seq), and selective deletion of the LepR in tanycytes, we are unable to detect expression of LepR in the tanycytes. Tanycyte-specific deletion of LepR likewise did not affect leptin-induced pSTAT3 expression in hypothalamic neurons, regardless of whether leptin was delivered by intraperitoneal or intracerebroventricular injection. Finally, we use activity-regulated scRNA-Seq (act-Seq) to comprehensively profile leptin-induced changes in gene expression in all cell types in mediobasal hypothalamus. Clear evidence for leptin signaling is only seen in endothelial cells and subsets of neurons, although virtually all cell types show leptin-induced changes in gene expression. We thus conclude that LepR expression in tanycytes is either absent or undetectably low, that tanycytes do not directly regulate hypothalamic leptin signaling through a LepR-dependent mechanism, and that leptin regulates gene expression in diverse hypothalamic cell types through both direct and indirect mechanisms.

scholarly journals Automated high-throughput registration for localizing 3D mouse brain gene expression using ITK

2005 ◽  
Author(s):  
Lydia Ng ◽  
Michael Hawrylycz ◽  
David Haynor
Keyword(s):  
Gene Expression ◽  
Mouse Brain ◽  
High Throughput ◽  
Image Data ◽  
Brain Structures ◽  
Brain Atlas ◽  
The Public ◽  
Brain Gene Expression ◽  
Genome Wide ◽  
Registration Scheme

The Allen Brain Atlas (ABA) project aims to create a cellular-resolution, genome-wide map of gene expression in the adult mouse brain. The resulting in situ hybridization (ISH) image data will be available free-of-charge to the public. Additionally, we are developing an informatics pipeline to support searching of the data by anatomic region and expression level and/or pattern. This paper describes a robust, high-throughput registration scheme to automatically annotate hierarchical brain structures in the ISH imagery.

scholarly journals Brain surface temperature under a craniotomy

2012 ◽  
Vol 108 (11) ◽  
pp. 3138-3146 ◽  
Author(s):  
Abigail S. Kalmbach ◽  
Jack Waters
Keyword(s):  
Heat Loss ◽  
Brain Temperature ◽  
Core Body Temperature ◽  
Region Of Interest ◽  
Brain Structures ◽  
Network Function ◽  
Cranial Window ◽  
Brain Surface ◽  
And Function ◽  
The Brain

Many neuroscientists access surface brain structures via a small cranial window, opened in the bone above the brain region of interest. Unfortunately this methodology has the potential to perturb the structure and function of the underlying brain tissue. One potential perturbation is heat loss from the brain surface, which may result in local dysregulation of brain temperature. Here, we demonstrate that heat loss is a significant problem in a cranial window preparation in common use for electrical recording and imaging studies in mice. In the absence of corrective measures, the exposed surface of the neocortex was at ∼28°C, ∼10°C below core body temperature, and a standing temperature gradient existed, with tissue below the core temperature even several millimeters into the brain. Cooling affected cellular and network function in neocortex and resulted principally from increased heat loss due to convection and radiation through the skull and cranial window. We demonstrate that constant perfusion of solution, warmed to 37°C, over the brain surface readily corrects the brain temperature, resulting in a stable temperature of 36–38°C at all depths. Our results indicate that temperature dysregulation may be common in cranial window preparations that are in widespread use in neuroscience, underlining the need to take measures to maintain the brain temperature in many physiology experiments.

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