scholarly journals Density of mushroom body synaptic complexes limits intraspecies brain miniaturization in highly polymorphic leaf-cutting ant workers

2014 ◽  
Vol 281 (1785) ◽  
pp. 20140432 ◽  
Author(s):  
Claudia Groh ◽  
Christina Kelber ◽  
Kornelia Grübel ◽  
Wolfgang Rössler
Keyword(s):  
Mushroom Body ◽  
Three Dimensional ◽  
Division Of Labour ◽  
Confocal Imaging ◽  
Total Brain Volume ◽  
Total Brain ◽  
Input Region ◽  
Leaf Cutting ◽  
Synaptic Complexes ◽  
Species Specific

Hymenoptera possess voluminous mushroom bodies (MBs), brain centres associated with sensory integration, learning and memory. The mushroom body input region (calyx) is organized in distinct synaptic complexes (microglomeruli, MG) that can be quantified to analyse body size-related phenotypic plasticity of synaptic microcircuits in these small brains. Leaf-cutting ant workers ( Atta vollenweideri ) exhibit an enormous size polymorphism, which makes them outstanding to investigate neuronal adaptations underlying division of labour and brain miniaturization. We particularly asked how size-related division of labour in polymorphic workers is reflected in volume and total numbers of MG in olfactory calyx subregions. Whole brains of mini, media and large workers were immunolabelled with anti-synapsin antibodies, and mushroom body volumes as well as densities and absolute numbers of MG were determined by confocal imaging and three-dimensional analyses. The total brain volume and absolute volumes of olfactory mushroom body subdivisions were positively correlated with head widths, but mini workers had significantly larger MB to total brain ratios. Interestingly, the density of olfactory MG was remarkably independent from worker size. Consequently, absolute numbers of olfactory MG still were approximately three times higher in large compared with mini workers. The results show that the maximum packing density of synaptic microcircuits may represent a species-specific limit to brain miniaturization.

scholarly journals Pyruvate to Lactate Metabolic Changes during Neurodevelopment Measured Dynamically Using Hyperpolarized 13C Imaging in Juvenile Murine Brain

2015 ◽  
Vol 38 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Yiran Chen ◽  
Hosung Kim ◽  
Robert Bok ◽  
Subramaniam Sukumar ◽  
Xin Mu ◽  
...  
Keyword(s):  
Body Weight ◽  
Magnetic Resonance ◽  
Mouse Brain ◽  
Brain Volume ◽  
Metabolic Changes ◽  
Brain Maturation ◽  
Multiple Time ◽  
Total Brain Volume ◽  
Hyperpolarized 13C ◽  
Total Brain

Hyperpolarized 13C magnetic resonance imaging has recently been used to dynamically image metabolism in vivo. This technique provides the capability to investigate metabolic changes in mouse brain development over multiple time points. In this study, we used 13C magnetic resonance spectroscopic imaging and hyperpolarized 13C-1-labeled pyruvate to analyze its conversion into lactate. We also applied T2-weighted anatomical imaging to examine brain volume changes starting from postnatal day 18 (P18). We combined these results with body weight measurements for a comprehensive interpretation of mouse brain maturation. Both the produced lactate level and pyruvate to lactate conversion rate decreased with increasing age in a linear manner. Total brain volume remained the same after P18, even though body weight continued to grow exponentially. Our results have shown that the rate of metabolism of 13C-1 pyruvate to lactate in brain is high in the young mouse and decreases with age. The brain at P18 is still relatively immature and continues to develop even as the total brain volume remains the same.

Cognition, structural brain changes and complicated grief. A population-based study

2014 ◽  
Vol 45 (7) ◽  
pp. 1389-1399 ◽  
Author(s):  
H. C. Saavedra Pérez ◽  
M. A. Ikram ◽  
N. Direk ◽  
H. G. Prigerson ◽  
R. Freak-Poli ◽  
...  
Keyword(s):  
White Matter ◽  
Brain Volume ◽  
Complicated Grief ◽  
Population Based ◽  
Word Fluency ◽  
Total Brain Volume ◽  
Population Based Study ◽  
Total Brain ◽  
Fluency Task ◽  
Structural Brain

BackgroundSeveral psychosocial risk factors for complicated grief have been described. However, the association of complicated grief with cognitive and biological risk factors is unclear. The present study examined whether complicated grief and normal grief are related to cognitive performance or structural brain volumes in a large population-based study.MethodThe present research comprised cross-sectional analyses embedded in the Rotterdam Study. The study included 5501 non-demented persons. Participants were classified as experiencing no grief (n = 4731), normal grief (n = 615) or complicated grief (n = 155) as assessed with the Inventory of Complicated Grief. All persons underwent cognitive testing (Mini-Mental State Examination, Letter–Digit Substitution Test, Stroop Test, Word Fluency Task, word learning test – immediate and delayed recall), and magnetic resonance imaging to measure general brain parameters (white matter, gray matter), and white matter lesions. Total brain volume was defined as the sum of gray matter plus normal white matter and white matter lesion volume. Persons with depressive disorders were excluded and analyses were adjusted for depressive symptoms.ResultsCompared with no-grief participants, participants with complicated grief had lower scores for the Letter–Digit Substitution Test [Z-score −0.16 v. 0.04, 95% confidence interval (CI) −0.36 to −0.04, p = 0.01] and Word Fluency Task (Z-score −0.15 v. 0.03, 95% CI −0.35 to −0.02, p = 0.02) and smaller total volumes of brain matter (933.53 ml v. 952.42 ml, 95% CI −37.6 to −0.10, p = 0.04).ConclusionsParticipants with complicated grief performed poorly in cognitive tests and had a smaller total brain volume. Although the effect sizes were small, these findings suggest that there may be a neurological correlate of complicated grief, but not of normal grief, in the general population.

scholarly journals Three-dimensional Super-resolved Imaging of Paraffin-embedded Kidney Samples

2021 ◽  
Author(s):  
David Unnersjoe-Jess ◽  
Amer Ramdedovic ◽  
Martin Hoehne ◽  
Linus Butt ◽  
Felix C Koehler ◽  
...  
Keyword(s):  
New Technologies ◽  
Three Dimensional ◽  
Kidney Tissue ◽  
Confocal Imaging ◽  
Disease Assessment ◽  
Gold Standard Method ◽  
Filtration Barrier ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Monitoring Treatment

Diseases of the glomeruli, the renal filtration units, are a leading cause of progressive kidney disease. Assessment of the ultrastructure of podocytes at the glomerular filtration barrier is essential for diagnosing diverse disease entities, providing insight into the disease pathogenesis as well as monitoring treatment responses. New technologies, including super-resolved nanoscopy and expansion microscopy, as well as new sample preparation techniques, are starting to revolutionize imaging of biopsy specimens. However, our previous approaches for simple and fast three-dimensional imaging of optically cleared samples are to date not compatible with formalin fixed paraffin-embedded (FFPE) tissue, impeding application in clinical routine. Here we provide protocols that circumvent these limitations and allow for three dimensional STED and confocal imaging of FFPE kidney tissue with similar staining and image quality as compared to our previous approaches. This would increase the feasibility to implement these protocols in clinical routines, as FFPE is the gold standard method for storage of patient samples.

scholarly journals Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

2014 ◽  
Author(s):  
Homayun Mehrabani ◽  
Neil Ray ◽  
Kyle Tse ◽  
Dennis Evangelista
Keyword(s):  
Surface Texture ◽  
Marine Invertebrates ◽  
Freezing Point ◽  
Three Dimensional ◽  
Surface Pattern ◽  
Ice Formation ◽  
Cold Air ◽  
Three Dimensional Printing ◽  
Species Specific ◽  
Effect Of Surface

Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g. Antarctic anchor ice), or in environments with moisture and cold air (e.g.vplants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We screened biological and artifical samples for ice formation and accretion in submerged conditions using previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. It appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels,Crassostrea gigas, or on the spines of the Antarctic sea urchinSterechinus neumayeri) slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams,Saxidomas nuttali). The geometric dimensions of the features have only a small (~6%) effect on ice formation. Surface texture affects ice formation, but does not explain by itself the large variation in ice formation and species-specific ice resistance observed in other work. This suggests future examination of other factors, such as material elastic properties and coatings, and their interaction with surface pattern.

Three-dimensional graphic reconstruction of the insect exoskeleton through confocal imaging of endogenous fluorescence

2000 ◽  
Vol 48 (6) ◽  
pp. 367-384 ◽  
Author(s):  
Sasha Zill ◽  
S. Faith Frazier ◽  
David Neff ◽  
Laura Quimby ◽  
Michelle Carney ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Confocal Imaging ◽  
Endogenous Fluorescence

Abstract T MP62: Acute Infarct Volume in Perinatal Stroke Can Be Accurately Estimated by Measuring Residual Uninfarcted Tissue on Follow-up MRI

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Nicholas V Stence ◽  
David M Mirsky ◽  
David Weitzenkamp ◽  
Sharon Poisson ◽  
Paco S Herson ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Direct Measurement ◽  
Infarct Volume ◽  
Arterial Ischemic Stroke ◽  
Total Brain Volume ◽  
Total Brain ◽  
Acute Infarct ◽  
Volume Measurements ◽  
Perinatal Arterial Ischemic Stroke

Introduction: Developing accurate measurements of infarct volume is vital to studying outcomes in Perinatal Arterial Ischemic Stroke (PAS). Methods for measuring Acute Infarct Volumes (aIV) are well established in PAS. However, techniques for measuring chronic infarct volume (cIV) in order to estimate aIV have not been validated and must account for changes in Total Brain Volume (TBV) over time, as well as contraction of the infarct. We compared two methods of measuring cIV, hypothesizing that cIV extrapolated from residual uninfarcted brain tissue volume would better estimate aIV than direct measurement of cIV. Methods: Using modified manual segmentation techniques, two pediatric neuroradiologists independently measured the brain and infarct volumes of 10 PAS patients both on the acute (0-7 days old) and chronic (>3 months) MRIs. Volume measurements were averaged after high inter-rater reliability was established (ICC>0.9). We evaluated acute and chronic scans for changes in infarct anatomy, and excluded patients with bilateral infarctions. Method 1 for estimating cIV used a direct measurement of the infarct (figure). Method 2 extrapolated infarct volume from residual uninfarcted brain tissue (figure). The cIV for each method was then compared to the aIV. Results: 3 patients with bilateral infarcts were excluded. Infarct anatomy between acute and chronic scans did not change for the 7 unilateral infarcts evaluated. In these 7 cases, the ICC comparing aIV and cIV from Method 1 was 0.507 (CI -0.120, 0.891), while the ICC comparing aIV and cIV from Method 2 was 0.964 (CI 0.821, 0.994). cIV’s from Method 1 were smaller than the aIV’s in all cases, despite stability of infarct anatomy. Conclusions: In this pilot study measuring cIV in PAS, direct measurement of cIV likely underestimates volume because of contraction of infarcted tissue. In conclusion, extrapolation of cIV from measurement of residual uninfarcted tissue appears to accurately estimate aIV.

Sign in / Sign up

Export Citation Format

Share Document