Decreased ß-cell volume and insulin secretion but preserved glucose tolerance in a growth hormone insensitive pig model.

PURPOSE: Growth hormone (GH) is a central regulator of ß-cell proliferation, insulin secretion and sensitivity. Aim of this study was to investigate the effect of GH insensitivity on pancreatic ß-cell histomorphology and consequences for metabolism in vivo. METHODS: Pancreata from pigs with growth hormone receptor deficiency (GHR-KO, n = 12) were analyzed by unbiased quantitative stereology in comparison to wild-type controls (WT, n = 12) at 3 and 7-8.5 months of age. In vivo secretion capacity for insulin and glucose tolerance were assessed by intravenous glucose tolerance tests (ivGTTs) in GHR-KO (n = 3) and WT (n = 3) pigs of the respective age groups. RESULTS: Unbiased quantitative stereological analyses revealed a significant reduction in total ß-cell volume (83% and 73% reduction in young and adult GHR-KO vs. age-matched WT pigs; p < 0.0001) and volume density of ß-cells in the pancreas of GHR-KO pigs (42% and 39% reduction in young and adult GHR-KO pigs; p = 0.0018). GHR-KO pigs displayed a significant, age-dependent increase in the proportion of isolated ß-cells in the pancreas (28% in young and 97% in adult GHR-KO vs. age-matched WT pigs; p = 0.0009). Despite reduced insulin secretion in ivGTTs, GHR-KO pigs maintained normal glucose tolerance. CONCLUSION: GH insensitivity in GHR-KO pigs leads to decreased ß-cell volume and volume proportion of ß-cells in the pancreas, causing a reduced insulin secretion capacity. The increased proportion of isolated ß-cells in the pancreas of GHR-KO pigs highlights the dependency on GH stimulation for proper ß-cell maturation. Preserved glucose tolerance accomplished with decreased insulin secretion indicates enhanced sensitivity for insulin in GH insensitivity.

Neuronal Stability, Volumetric Changes, and Decrease in GFAP Expression of Marmoset (Callithrix jacchus) Subcortical Visual Nuclei During Aging.

The physiological aging process is well known for functional decline in visual abilities. Among the components of the visual system, the dorsal lateral geniculate nucleus (DLG) and superior colliculus (SC) provide a good model for aging investigations, as these structures constitute the main visual pathways for retinal inputs reaching the visual cortex. However, there are limited data available on quantitative morphological and neurochemical aspects in DLG and SC across lifespan. Here, we used optical density to determine immunoexpression of glial fibrillary acidic protein (GFAP) and design-based stereological probes to estimate the neuronal number, total volume, and layer volume of the DLG and SC in marmosets (Callithrix jacchus), ranging from 36 to 143 months of age. Our results revealed an age-related increase in total volume and layer volume of the DLG, with an overall stability in SC volume. Furthermore, a stable neuronal number was demonstrated in DLG and superficial layers of SC (SCv). A decrease in GFAP immunoexpression was observed in both visual centers. The results indicate region-specific variability in volumetric parameter, possibly attributed to structural plastic events in response to inflammation and compensatory mechanisms at the cellular and subcellular level. Additionally, the DLG and SCv seem to be less vulnerable to aging effects in terms of neuronal number. The neuropeptidergic data suggest that reduced GFAP expression may reflect morphological atrophy in the astroglial cells. This study contributes to updating the current understanding of aging effects in the visual system and stablishes a crucial foundation for future research on visual perception throughout the aging process.

Quantifying myelin density in the feline auditory cortex.

The cerebral cortex comprises many distinct regions that differ in structure, function, and patterns of connectivity. Current approaches to parcellating these regions often take advantage of functional neuroimaging approaches that can identify regions involved in a particular process with reasonable spatial resolution. However, neuroanatomical biomarkers are also very useful in identifying distinct cortical regions either in addition to, or in place of functional measures. For example, differences in myelin density are thought to relate to functional differences between regions, are sensitive to individual patterns of experience, and have been shown to vary across functional hierarchies in a predictable manner. Accordingly, the current study provides quantitative stereological estimates of myelin density for each of the 13 regions that make up the feline auditory cortex. We demonstrate that significant differences can be observed between auditory cortical regions, with the highest myelin density observed in the regions that comprise the auditory core (i.e., the primary auditory cortex and anterior auditory field). Moreover, our myeloarchitectonic map suggests that myelin density varies in a hierarchical fashion that conforms to the traditional model of spatial organization in auditory cortex. Taken together, these results establish myelin as a useful biomarker for parcellating auditory cortical regions, and provide detailed estimates against which other, less invasive methods of quantifying cortical myelination may be compared.

Autistic-like behaviour and changes in thalamic cell numbers a rat model of valproic acid-induced autism; A behavioural and stereological study.

The contribution of the thalamus to the development and behavioural changes in autism spectrum disorders (ASD), a neurodevelopmental syndrome, remains unclear. The aim of this study was to determine the changes in thalamic volume and cell number in the valproic acid (VPA)-induced ASD model using stereological methods and to clarify the relationship between thalamus and ASD-like behaviour. Ten pregnant rats were administered a single dose (600 mg/kg) of VPA intraperitoneally on G12.5 (VPA group), while five pregnant rats were injected with 5 ml saline (control group). Behavioural tests were performed to determine appropriate subjects and ASD-like behaviours. At P55, the brains of the subjects were removed. The sagittal sections were stained with cresyl violet and toluidine blue. The thalamic and hemispheric volumes with their ratios, the total number of thalamic cells, neurons and non-neuronal cells were calculated using stereological methods. Data were compared using a t-test and a Pearson correlation analysis was performed to examine the relationship between behaviour and stereological outcomes. VPA-treated rats had lower sociability and sociability indexes. There was no difference in social novelty preference and anxiety. The VPA group had larger hemispheric volume, lower thalamic volume, and fewer neurons. The highest percentage decrease was in non-neuronal cells. There was a moderate positive correlation between the number of non-neuronal cells and sociability, thalamic volume and the number of neurons as well as the time spent in the light box. The correlation between behaviour and stereological data suggests that the thalamus is associated with ASD-like behaviour.

Deep learning-based localization algorithms on fluorescence human brain 3D reconstruction: a comparative study using stereology as a reference.

3D reconstruction of human brain volumes at high resolution is now possible thanks to advancements in tissue clearing methods and fluorescence microscopy techniques. Analyzing the massive data produced with these approaches requires automatic methods able to perform fast and accurate cell counting and localization. Recent advances in deep learning have enabled the development of various tools for cell segmentation. However, accurate quantification of neurons in the human brain presents specific challenges, such as high pixel intensity variability, autofluorescence, non-specific fluorescence and very large size of data. In this paper, we provide a thorough empirical evaluation of three techniques based on deep learning (StarDist, CellPose and BCFind-v2, an updated version of BCFind) using a recently introduced three-dimensional stereological design as a reference for large-scale insights. As a representative problem in human brain analysis, we focus on a 4 -cm 3 portion of the Broca's area. We aim at helping users in selecting appropriate techniques depending on their research objectives. To this end, we compare methods along various dimensions of analysis, including correctness of the predicted density and localization, computational efficiency, and human annotation effort. Our results suggest that deep learning approaches are very effective, have a high throughput providing each cell 3D location, and obtain results comparable to the estimates of the adopted stereological design.

Investigating Contributions of Canonical Transient Receptor Potential Channel 3 to Hippocampal Hyperexcitability and Seizure-Induced Neuronal Cell Death.

Canonical transient receptor potential channel 3 (TRPC3) is the most abundant TRPC channel in the brain and is highly expressed in all subfields of the hippocampus. Previous studies have suggested that TRPC3 channels may be involved in the hyperexcitability of hippocampal pyramidal neurons and seizures. Genetic ablation of TRPC3 channel expression reduced the intensity of pilocarpine-induced status epilepticus (SE). However, the underlying cellular mechanisms remain unexplored and the contribution of TRPC3 channels to SE-induced neurodegeneration is not determined. In this study, we investigated the contribution of TRPC3 channels to the electrophysiological properties of hippocampal pyramidal neurons and hippocampal synaptic plasticity, and the contribution of TRPC3 channels to seizure-induced neuronal cell death. We found that genetic ablation of TRPC3 expression did not alter basic electrophysiological properties of hippocampal pyramidal neurons and had a complex impact on epileptiform bursting in CA3. However, TRPC3 channels contribute significantly to long-term potentiation in CA1 and SE-induced neurodegeneration. Our results provided further support for therapeutic potential of TRPC3 inhibitors and raised new questions that need to be answered by future studies.

Volumetric study on sheep brain using stereology technique.

Three-dimensional morphometric data better show the structural and functional characteristics of the brain. The objective of this study was to estimate the volume of the cerebral structures of the sheep using design-based stereology. The brains of five sheep were used, fixed in formalin 10% and embedded in agar 6%. An average of 10-12 slab was obtained from each brain. All slabs were stained using Mulligan's method and photographs were recorded. The volume of the brain and its structures were estimated using the Cavalieri's estimator and the point counting system. The total volume was 70604.8 ± 132.45 mm3. The volume fractions of the grey and white matters were calculated as 42.55 ± 0.21% and 24.23 ± 0.51% of the whole brain, respectively. The fractional volume of the caudate nucleus and claustrum were estimated at 2.39 ± 0.08% and at 1.008 ± 0.057% of total brain volume. The volumes of corpus callosum, internal capsule and external capsule were 1.24 ± 0.053%, 3.63 ± 0.22% and 0.698 ± 0.049% of total cerebral volume, respectively. These data could help improve the veterinary comparative neuroanatomy knowledge and development of experimental studies in the field.

No Evidence of Sensory Neuropathy in a Traditional Mouse Model of Idiopathic Parkinson's Disease.

Parkinson's disease (PD) is the second-most common neurodegenerative disorder worldwide and is diagnosed based on motor impairments. Non-motor symptoms are also well-recognised in this disorder, and peripheral neuropathy is a frequent but poorly appreciated non-motor sign. Studying how central and peripheral sensory systems are affected can contribute to the development of targeted therapies and deepen our understanding of the pathophysiology of PD. Although the cause of sporadic PD is unknown, chronic exposure to the pesticide rotenone in humans increases the risk of developing the disease. Here, we aimed to investigate whether peripheral neuropathy is present in a traditional model of PD. Mice receiving intrastriatal rotenone showed greatly reduced dopamine terminals in the striatum and a reduction in tyrosine hydroxylase-positive neurons in the Substantia nigra pars compacta and developed progressive motor impairments in hindlimb stepping and rotarod but no change in spontaneous activity. Interestingly, repeated testing using gold-standard protocols showed no change in gut motility, a well-known non-motor symptom of PD. Importantly, we did not observe any change in heat, cold, or touch sensitivity, again based upon repeated testing with well-validated protocols that were statistically well powered. Therefore, this traditional model fails to replicate PD, and our data again reiterate the importance of the periphery to the disorder.

The fix is not yet in: recommendation for fixation of lungs within physiologic/pathophysiologic volume range in preclinical pulmonary structure-function studies.

Quantitative characterization of lung structures by morphometric or stereologic analysis of histologic sections is a powerful means of elucidating pulmonary structure-function relations. The overwhelming majority of studies, however, fix lungs for histology at pressures outside the physiologic/pathophysiologic respiratory volume range. Thus valuable information is being lost. In this perspective article, we argue that investigators performing pulmonary histologic studies should consider whether the aims of their studies would benefit from fixation at functional transpulmonary pressures, particular those of end-inspiration and end-expiration. We survey the pressures at which lungs are typically fixed in preclinical structure-function studies; provide examples of conditions that would benefit from histologic evaluation at functional lung volumes; summarize available fixation methods; discuss alternative imaging modalities; and discuss challenges to implementing the suggested approach and means of addressing those challenges. We aim to persuade investigators that modifying or complementing the traditional histologic approach by fixing lungs at minimal and maximal functional volumes could enable new understanding of pulmonary structure-function relations.

Low-volume ventilation of preinjured lungs degrades lung function via stress concentration and progressive alveolar collapse.

Mechanical ventilation can cause ventilation-induced lung injury (VILI). The concept of stress concentrations suggests that surfactant dysfunction-induced microatelectases might impose injurious stresses on adjacent, open alveoli and function as germinal centers for injury propagation. The aim of the present study was to quantify the histopathological pattern of VILI progression and to test the hypothesis that injury progresses at the interface between microatelectases and ventilated lung parenchyma during low-positive end-expiratory pressure (PEEP) ventilation. Bleomycin was used to induce lung injury with microatelectases in rats. Lungs were then mechanically ventilated for up to 6 h at PEEP = 1 cmH2O and compared with bleomycin-treated group ventilated protectively with PEEP = 5 cmH2O to minimize microatelectases. Lung mechanics were measured during ventilation. Afterward, lungs were fixed at end-inspiration or end-expiration for design-based stereology. Before VILI, bleomycin challenge reduced the number of open alveoli [N(alvair,par)] by 29%. No differences between end-inspiration and end-expiration were observed. Collapsed alveoli clustered in areas with a radius of up to 56 µm. After PEEP = 5 cmH2O ventilation for 6 h, N(alvair,par) remained stable while PEEP = 1 cmH2O ventilation led to an additional loss of aerated alveoli by 26%, mainly due to collapse, with a small fraction partly edema filled. Alveolar loss strongly correlated to worsening of tissue elastance, quasistatic compliance, and inspiratory capacity. The radius of areas of collapsed alveoli increased to 94 µm, suggesting growth of the microatelectases. These data provide evidence that alveoli become unstable in neighborhood of microatelectases, which most likely occurs due to stress concentration-induced local vascular leak and surfactant dysfunction.NEW & NOTEWORTHY Low-volume mechanical ventilation in the presence of high surface tension-induced microatelectases leads to the degradation of lung mechanical function via the progressive loss of alveoli. Microatelectases grow at the interfaces of collapsed and open alveoli. Here, stress concentrations might cause injury and alveolar instability. Accumulation of small amounts of alveolar edema can be found in a fraction of partly collapsed alveoli but, in this model, alveolar flooding is not a major driver for degradation of lung mechanics.

Morphological evidence for the potential protective effects of curcumin and Garcinia kola against diabetes in the rat hippocampus.

This research investigated the effects of sciatic nerve transection and diabetes on the hippocampus, and the protective effects of Garcinia kola and curcumin. Thirty-five adults male Wistar albino rats were divided into five groups: a control group (Cont), a transected group (Sham group), a transected + diabetes mellitus group (DM), a transected + diabetes mellitus + Garcinia kola group (DM + GK), and a transected + DM + curcumin group (DM + Cur), each containing seven animals. The experimental diabetes model was created with the intraperitoneal injection of a single dose of streptozotocin. No procedure was applied to the Cont group, while sciatic nerve transection was performed on the other groups. Garcinia kola was administered to the rats in DM + GK, and curcumin to those in DM + Cur. Cardiac perfusion was performed at the end of the experimental period. Brain tissues were dissected for stereological, histopathological, and immunohistochemical evaluations. The volume ratios of hippocampal layers to the entire hippocampus volume were compared between the groups. Anti-S100, anti-caspase 3, and anti-SOX 2 antibodies were used for immunohistochemical analysis. No statistically significant difference was observed in the volume ratios of the four hippocampal layers. However, the volume ratio of the stratum lucidum was higher in the Sham, DM, and DM + Cur groups compared to the Cont group. While curcumin exhibited a protective effect on hippocampal tissue following diabetes induction, Garcinia kola had only a weak protective effect. Increased cell density and nuclear deterioration due to diabetes and nerve transection can be partially ameliorated by treatment with Garcinia kola and curcumin.

Exploring alveolar recruitability using positive end-expiratory pressure in mice overexpressing TGF-ß1: a structure-function analysis.

Pre-injured lungs are prone to injury progression in response to mechanical ventilation. Heterogeneous ventilation due to (micro)atelectases imparts injurious strains on open alveoli (known as volutrauma). Hence, recruitment of (micro)atelectases by positive end-expiratory pressure (PEEP) is necessary to interrupt this vicious circle of injury but needs to be balanced against acinar overdistension. In this study, the lung-protective potential of alveolar recruitment was investigated and balanced against overdistension in pre-injured lungs. Mice, treated with empty vector (AdCl) or adenoviral active TGF-ß1 (AdTGF-ß1) were subjected to lung mechanical measurements during descending PEEP ventilation from 12 to 0 cmH2O. At each PEEP level, recruitability tests consisting of two recruitment maneuvers followed by repetitive forced oscillation perturbations to determine tissue elastance (H) and damping (G) were performed. Finally, lungs were fixed by vascular perfusion at end-expiratory airway opening pressures (Pao) of 20, 10, 5 and 2 cmH2O after a recruitment maneuver, and processed for design-based stereology to quantify derecruitment and distension. H and G were significantly elevated in AdTGF-ß1 compared to AdCl across PEEP levels. H was minimized at PEEP = 5-8 cmH2O and increased at lower and higher PEEP in both groups. These findings correlated with increasing septal wall folding (= derecruitment) and reduced density of alveolar number and surface area (= distension), respectively. In AdTGF-ß1 exposed mice, 27% of alveoli remained derecruited at Pao = 20 cmH2O. A further decrease in Pao down to 2 cmH2O showed derecruitment of an additional 1.1 million alveoli (48%), which was linked with an increase in alveolar size heterogeneity at Pao = 2-5 cmH2O. In AdCl, decreased Pao resulted in septal folding with virtually no alveolar collapse. In essence, in healthy mice alveoli do not derecruit at low PEEP ventilation. The potential of alveolar recruitability in AdTGF-ß1 exposed mice is high. H is optimized at PEEP 5-8 cmH2O. Lower PEEP folds and larger PEEP stretches septa which results in higher H and is more pronounced in AdTGF-ß1 than in AdCl. The increased alveolar size heterogeneity at Pao = 5 cmH2O argues for the use of PEEP = 8 cmH2O for lung protective mechanical ventilation in this animal model.

The IC87201 (a PSD95/nNOS Inhibitor) Attenuates Post- Stroke Injuries.

N-methyl-D-aspartate receptor-dependent excitotoxicity is one of the most important mechanisms underlying stroke injury and the resulting neuronal death. In the present study, in order to reduce post-stroke brain injury and improve behavioral performance, a new molecule named IC87201, which acts as an inhibitor of PSD95/nNOS interaction in the intracellular signaling pathway of NMDA receptors, was administered. Using the middle cerebral artery occlusion (MCAO) technique, 24 adult male rats were subjected to one hour of cerebral ischemia. Animals were randomly divided into sham, MCAO, MCAO + DXM, and MCAO + IC87201 groups, and in the last two groups, intraperitoneal injection of dextromethorphan hydrobromide monohydrate (DXM), as an NMDA antagonist, and IC87201 was performed after ischemia. Neurobehavioral scores were evaluated for seven days, and on the last two days, the rats' memory performance was appraised using the passive avoidance test. On seventh day, the brain tissue was properly prepared for stereological analysis. Stereological studies of the hippocampus CA1 and CA3 regions revealed that changes in the total and infarcted volumes, total number of neurons, non-neurons, and dead neurons are the consequences of cerebral ischemia. Also, following cerebral ischemia, neurobehavioral and memory function impairments which were assessed by modified neurological severity scores (mNSS) and passive avoidance test, were observed. The aforementioned impairments were recovered after administration of IC87201 significantly and more potently than DXM. Based on our findings, IC87201 successfully attenuated post-ischemia damages. Therefore, this molecule can be considered as a new therapeutic approach in future research.

Three-dimensional morphometry of kidney in New Zealand rabbit using unbiased design-based stereology.

The rabbit is widely used as a laboratory animal in experimental models of kidney diseases. This species is also important from a veterinary perspective as a companion animal. Stereology has been accepted as an accurate approach to kidney morphometry. The objective of the present project was to provide normal quantitative stereological parameters for adult rabbit kidneys. The left kidneys of five adult male New Zealand rabbits were used. Isotropic sections were obtained using the orientation method. Total kidney volume was calculated by the Cavalieri principle. The volume fraction of the renal structures was estimated using the point counting system. The lengths of the proximal convoluted tubule (PCT) and distal convoluted tubule (DCT) were calculated using counting frames. The total glomerular number was accounted for using the physical/fractionator technique. The mean glomerular volume was obtained by dividing the total volume of glomeruli by their total number. The total volume of rabbit kidneys calculated was 10.39 ± 1.98 cm3. The fractional volume of the kidney cortex and medulla accounted for 57.79 ± 0.65% and 42.2 ± 0.65%, respectively. The total glomerular volume was 2.18 ± 0.32% of the whole kidney. The total number of glomeruli in the rabbit kidney was estimated as 204.68 ± 12 × 103. The mean glomerular volume measured 1.07 ± 0.12 × 106 µm3. The total length of PCT and DCT was 2.96 ± 0.29 km and 1.38 ± 0.24 km, respectively. These findings can be used as a reference in experimental nephrology research and may help to expand the knowledge of nephrology in mammals by comparing with available data on humans and other species. RESEARCH HIGHLIGHTS: Three-dimensional morphometry of adult rabbit kidney structures was analyzed using quantitative stereology. Total volume of kidney, fractional volume of cortex and medulla, length of renal tubules and number of nephrons were estimated. These three-dimensional morphometrical data can be used as a reference in experimental nephrology research and may help to expand the knowledge of nephrology in mammals.

The neuroprotective effects of baobab and black seed on the rat hippocampus exposed to a 900-MHz electromagnetic field.

This study investigated the potential effects on the hippocampus of electromagnetic fields (EMFs) disseminated by mobile phones and the roles of baobab (Adansonia digitata) (AD) and black seed (Nigella sativa) (BS) in mitigating these. Fifty-six male, 12-week-old Wistar albino rats were divided into eight groups of seven animals each. No EMF exposure was applied to the control, AD or BS groups, while the rats in the Sham group were placed in an EMF system with no exposure. A 900-MHz EMF was applied to the EMF+AD, EMF+BS, EMF+AD+BS and EMF groups for 1 hour a day for 28 days. Pyramidal neurons in the hippocampus were subsequently counted using the optical fractionator technique, one of the unbiased stereological methods. Tissue sections were also evaluated histopathologically under light and electron microscopy. The activities of the enzymes catalase (CAT) and superoxide dismutase (SOD) were also determined in blood serum samples. Analysis of the stereological data revealed no statistically significant differences between the EMF and control or sham groups in terms of pyramidal neuron numbers (p>0.05). However, stereological examination revealed a crucial difference in the entire hippocampus between the control group and the AD (p<0.01) and BS (p<0.05) groups. Moreover, exposure to 900-MHz EMF produced adverse changes in the structures of neurons at histopathological analysis. Qualitative examinations suggest that a combination of herbal products such as AD and BS exerts a protective effect against such EMF side-effects.

Mucopolysaccharidosis (MPS IIIA) mice have increased lung compliance and airway resistance, decreased diaphragm strength, and no change in alveolar structure.

Mucopolysaccharidosis type IIIA (MPS IIIA) is characterized by neurological and skeletal pathologies caused by reduced activity of the lysosomal hydrolase, sulfamidase, and the subsequent primary accumulation of undegraded heparan sulfate (HS). Respiratory pathology is considered secondary in MPS IIIA and the mechanisms are not well understood. Changes in the amount, metabolism, and function of pulmonary surfactant, the substance that regulates alveolar interfacial surface tension and modulates lung compliance and elastance, have been reported in MPS IIIA mice. Here we investigated changes in lung function in 20-wk-old control and MPS IIIA mice with a closed and open thoracic cage, diaphragm contractile properties, and potential parenchymal remodeling. MPS IIIA mice had increased compliance and airway resistance and reduced tissue damping and elastance compared with control mice. The chest wall impacted lung function as observed by an increase in airway resistance and a decrease in peripheral energy dissipation in the open compared with the closed thoracic cage state in MPS IIIA mice. Diaphragm contractile forces showed a decrease in peak twitch force, maximum specific force, and the force-frequency relationship but no change in muscle fiber cross-sectional area in MPS IIIA mice compared with control mice. Design-based stereology did not reveal any parenchymal remodeling or destruction of alveolar septa in the MPS IIIA mouse lung. In conclusion, the increased storage of HS which leads to biochemical and biophysical changes in pulmonary surfactant also affects lung and diaphragm function, but has no impact on lung or diaphragm structure at this stage of the disease.NEW & NOTEWORTHY Heparan sulfate storage in the lungs of mucopolysaccharidosis type IIIA (MPS IIIA) mice leads to changes in lung function consistent with those of an obstructive lung disease and includes an increase in lung compliance and airway resistance and a decrease in tissue elastance. In addition, diaphragm muscle contractile strength is reduced, potentially further contributing to lung function impairment. However, no changes in parenchymal lung structure were observed in mice at 20 wk of age.

PGC-1α in the hippocampus mediates depressive-like and stress-coping behaviours and regulates excitatory synapses in the dentate gyrus in mice.

Decreased hippocampal synaptic plasticity is an important pathological change in stress-related mood disorders, including major depressive disorder. However, the underlying mechanism is unclear. PGC-1α, a transcriptional coactivator, is a key factor in synaptic plasticity. We investigated the relationships between changes in hippocampal PGC-1α expression and depressive-like and stress-coping behaviours, and whether they are related to hippocampal synapses. Adeno-associated virus was used to alter hippocampal PGC-1α expression in male C57BL/6 mice. The sucrose preference test and forced swimming test were used to assess their depressive-like and stress-coping behaviours, respectively. Immunohistochemistry and stereology were used to calculate the total number of excitatory synapses in each hippocampal subregion (the cornu ammonis (CA) 1, CA3, and dentate gyrus). Immunofluorescence was used to visualize the changes in dendritic structure. Western blotting was used to detect the expression of hippocampal PGC-1α and mitochondrial-associated proteins, such as UCP2, NRF1 and mtTFAs. Our results showed that mice with downregulated PGC-1α expression in the hippocampus exhibited depressive-like and passive stress-coping behaviours, while mice with upregulated PGC-1α in the hippocampus exhibited increased stress-coping behaviours. Moreover, the downregulation of hippocampal PGC-1α expression resulted in a decrease in the number of excitatory synapses in the DG and in the protein expression of UCP2 in the hippocampus. Alternatively, upregulation of hippocampal PGC-1α yielded the opposite results. This suggests that hippocampal PGC-1α is involved in regulating depressive-like and stress-coping behaviours and modulating the number of excitatory synapses in the DG. This provides new insight for the development of antidepressants.

Foaming and Physico-Mechanical Properties of Geopolymer Pastes Manufactured from Post-Metallurgical Recycled Slag.

This paper presents a research program aimed towards developing a method of producing lightweight, porous geopolymer composites for the construction industry based on industrial wastes. A direct method involving the addition of chemicals is currently most commonly used to produce the porous mineral structure of a geopolymer matrix. This relies on a reaction in a highly alkaline environment of the geopolymer to produce a gas (usually hydrogen or oxygen) that forms vesicles and creates a network of pores. This paper demonstrates the feasibility of producing a slag-based geopolymer paste foamed with aluminum powder, taking into account different parameters of fresh paste production: the mixing duration, its speed and the timing of foaming agent addition. The foaming process of the fresh paste in terms of the volumetric changes and temperature development of the fresh paste during the curing of the material are observed. After hardening, the physical properties (density and porosity) as well as the mechanical parameters (compressive strength and work of damage) are determined for the nine manufactured foamed pastes. Image analysis software was used to assess the porosity distribution of the material across the cross-section of the samples. The results enabled the design of the mixing procedure to be adopted during the manufacture of such composites.

Nuclear parcellation and numbers of orexinergic neurons in five species of larger brained birds.

The orexinergic/hypocretinergic system, while having several roles, appears to be a key link in the balance between arousal and food intake. In birds, to date, this system has only been examined anatomically in four species, all with brains smaller than 3.5 g and of limited phylogenetic range. Here, using orexin-A immunohistochemistry, we describe the distribution, morphology, and nuclear parcellation of orexinergic neurons within the hypothalami of a Congo gray and a Timneh gray parrot, a pied crow, an emu, and a common ostrich. These birds represent a broad phylogeny, with brains ranging in size from 7.85 to 26.5 g. Within the hypothalami of the species studied, the orexinergic neurons were organized in two clusters, and a densely packed paraventricular hypothalamic nucleus cluster located within the medial hypothalamus (Hyp), but not contacting the ventricle, and a more loosely packed lateral hypothalamic cluster in the lateral Hyp. Stereological analysis revealed a strong correlation, using phylogenetic generalized least squares regression analyses, between brain mass and the total number of orexinergic neurons, as well as soma parameters such as volume and area. Orexinergic axonal terminals evinced two types of boutons, larger and the smaller en passant boutons. Unlike the orexinergic system in mammals, which has several variances in cluster organization, that of the birds studied, in the present and previous studies, currently shows organizational invariance, despite the differences in brain and body mass, phylogenetic relationships, and life-histories of the species studied.

Empagliflozin reduces the adverse effects of diabetes mellitus on testicular tissue in type 2 diabetic Rats: A stereological and biochemical study.

Empagliflozin as an antioxidant decreases blood glucose and insulin resistance in type 2 diabetes mellitus. Base on the empagliflozin antioxidant properties we decided to investigate the its effects on the testis histological changes through stereological techniques and biochemical evaluations in T2 diabetes mellitus rats. Rats were divided into: control, diabetes mellitus (DM, streptozotocin + nicotinamide) and diabetes mellitus + empagliflozin (DM + EMPA, 10 mg/kg/day) groups. 56 days after inducing diabetes mellitus testis histological changes and serum biochemical factors along with the level of Bax, Bcl2 and Nrf2 genes expression in the testicular tissue were assessed. A significant decrease in the mean total volume of testis and its components, the level of Bcl2 and Nrf2 gene expression (p < 0.001) along with a significant increase in the level of IL-6, TNF-α, MDA, Bax gene expression were observed in the DM group compared to the control group (p < 0.001). In the DM + EMPA group, the mean total volume of testis and its components, the level of Bcl2 gene expression (p< 0.01) and Nrf2 (p < 0.001) significantly increased whereas the mean level of IL-6 (p < 0.01), TNF-α (p < 0.001), MDA (p < 0.001), Bax (p < 0.001) gene expression significantly decreased compared to the DM group. Our results showed that empagliflozin, by improving the antioxidant defense system, can reduce testicular inflammation and apoptosis and partly prevent the adverse effects of diabetes mellitus on testicular tissue.