Two dynamically distinct circuits drive inhibition in the sensory thalamus.

Most sensory information destined for the neocortex is relayed through the thalamus, where considerable transformation occurs1,2. One means of transformation involves interactions between excitatory thalamocortical neurons that carry data to the cortex and inhibitory neurons of the thalamic reticular nucleus (TRN) that regulate the flow of those data3-6. Although the importance of the TRN has long been recognised7-9, understanding of its cell types, their organization and their functional properties has lagged behind that of the thalamocortical systems they control. Here we address this by investigating the somatosensory and visual circuits of the TRN in mice. In the somatosensory TRN we observed two groups of genetically defined neurons that are topographically segregated and physiologically distinct, and that connect reciprocally with independent thalamocortical nuclei through dynamically divergent synapses. Calbindin-expressing cells-located in the central core-connect with the ventral posterior nucleus, the primary somatosensory thalamocortical relay. By contrast, somatostatin-expressing cells-which reside along the surrounding edges of the TRN-synapse with the posterior medial thalamic nucleus, a higher-order structure that carries both top-down and bottom-up information10-12. The two TRN cell groups process their inputs in pathway-specific ways. Synapses from the ventral posterior nucleus to central TRN cells transmit rapid excitatory currents that depress deeply during repetitive activity, driving phasic spike output. Synapses from the posterior medial thalamic nucleus to edge TRN cells evoke slower, less depressing excitatory currents that drive more persistent spiking. Differences in the intrinsic physiology of TRN cell types, including state-dependent bursting, contribute to these output dynamics. The processing specializations of these two somatosensory TRN subcircuits therefore appear to be tuned to the signals they carry-a primary central subcircuit tuned to discrete sensory events, and a higher-order edge subcircuit tuned to temporally distributed signals integrated from multiple sources. The structure and function of visual TRN subcircuits closely resemble those of the somatosensory TRN. These results provide insights into how subnetworks of TRN neurons may differentially process distinct classes of thalamic information.

Cortical dysmorphology and reduced cortico-collicular projections in an animal model of autism spectrum disorder.

Autism spectrum disorder is a neurodevelopmental disability that includes sensory disturbances. Hearing is frequently affected and ranges from deafness to hypersensitivity. In utero exposure to the antiepileptic valproic acid is associated with increased risk of autism spectrum disorder in humans and timed valproic acid exposure is a biologically relevant and validated animal model of autism spectrum disorder. Valproic acid-exposed rats have fewer neurons in their auditory brainstem and thalamus, fewer calbindin-positive neurons, reduced ascending projections to the midbrain and thalamus, elevated thresholds, and delayed auditory brainstem responses. Additionally, in the auditory cortex, valproic acid exposure results in abnormal responses, decreased phase-locking, elevated thresholds, and abnormal tonotopic maps. We therefore hypothesized that in utero, valproic acid exposure would result in fewer neurons in auditory cortex, neuronal dysmorphology, fewer calbindin-positive neurons, and reduced connectivity. We approached this hypothesis using morphometric analyses, immunohistochemistry, and retrograde tract tracing. We found thinner cortical layers but no changes in the density of neurons, smaller pyramidal and non-pyramidal neurons in several regions, fewer neurons immunoreactive for calbindin-positive, and fewer cortical neurons projecting to the inferior colliculus. These results support the widespread impact of the auditory system in autism spectrum disorder and valproic acid-exposed animals and emphasize the utility of simple, noninvasive auditory screening for autism spectrum disorder.

Interneurons in the CA1 stratum oriens expressing αTTP may play a role in the delayed-ageing Pol µ mouse model.

Neurodegeneration associated with ageing is closely linked to oxidative stress (OS) and disrupted calcium homeostasis. Some areas of the brain, like the hippocampus - particularly the CA1 region - have shown a high susceptibility to age-related changes, displaying early signs of pathology and neuronal loss. Antioxidants such as α-tocopherol (αT) have been effective in mitigating the impact of OS during ageing. αT homeostasis is primarily regulated by the α-tocopherol transfer protein (αTTP), which is widely distributed throughout the brain - where it plays a crucial role in maintaining αT levels within neuronal cells. This study investigates the distribution of αTTP in the hippocampus of 4- and 24-month-old Pol µ knockout mice (Pol µ-/-), a delayed-ageing model, and the wild type (Pol µ+/+). We also examine the colocalisation in the stratum oriens (st.or) of CA1 region with the primary interneuron populations expressing calcium-binding proteins (CBPs) (calbindin (CB), parvalbumin (PV), and calretinin (CR)). Our findings reveal that αTTP immunoreactivity (-IR) in the st.or of Pol µ mice is significantly reduced. The density of PV-expressing interneurons (INs) increased in aged mice in both Pol µ genotypes (Pol µ-/- and Pol µ+/+), although the density of PV-positive INs was lower in the aged Pol µ-/- mice compared to wild-type mice. By contrast, CR- and CB-positive INs in Pol µ mice remained unchanged during ageing. Furthermore, double immunohistochemistry reveals the colocalisation of αTTP with CBPs in INs of the CA1 st.or. Our study also shows that the PV/αTTP-positive IN population remains unchanged in all groups. A significant decrease of CB/αTTP-positive INs in young Pol µ-/- mice has been detected, as well as a significant increase in CR/αTTP-IR in older Pol µ-/- animals. These results suggest that the differential expression of αTTP and CBPs could have a crucial effect in aiding the survival and maintenance of the different IN populations in the CA1 st.or, and their coexpression could contribute to the enhancement of their resistance to OS-related damage and neurodegeneration associated with ageing.

Localization of PDE4D, HCN1 channels, and mGluR3 in rhesus macaque entorhinal cortex may confer vulnerability in Alzheimer's disease.

Alzheimer's disease cortical tau pathology initiates in the layer II cell clusters of entorhinal cortex, but it is not known why these specific neurons are so vulnerable. Aging macaques exhibit the same qualitative pattern of tau pathology as humans, including initial pathology in layer II entorhinal cortex clusters, and thus can inform etiological factors driving selective vulnerability. Macaque data have already shown that susceptible neurons in dorsolateral prefrontal cortex express a "signature of flexibility" near glutamate synapses on spines, where cAMP-PKA magnification of calcium signaling opens nearby potassium and hyperpolarization-activated cyclic nucleotide-gated channels to dynamically alter synapse strength. This process is regulated by PDE4A/D, mGluR3, and calbindin, to prevent toxic calcium actions; regulatory actions that are lost with age/inflammation, leading to tau phosphorylation. The current study examined whether a similar "signature of flexibility" expresses in layer II entorhinal cortex, investigating the localization of PDE4D, mGluR3, and HCN1 channels. Results showed a similar pattern to dorsolateral prefrontal cortex, with PDE4D and mGluR3 positioned to regulate internal calcium release near glutamate synapses, and HCN1 channels concentrated on spines. As layer II entorhinal cortex stellate cells do not express calbindin, even when young, they may be particularly vulnerable to magnified calcium actions and ensuing tau pathology.

Urinary Concentration of Renal Biomarkers in Healthy Term Neonates: Gender Differences in GST-pi Excretion.

BACKGROUND Serum creatinine, the criterion standard in assessment of renal function, is not reliable for the neonatal period because of its dependence on renal immaturity and maternal creatinine levels. Thus, it is important to study other biomarkers of renal function in neonates. The present study aimed to measure the urinary concentration of renal biomarkers: calbindin, clusterin, GST-pi (glutathione-S-transferase-alpha), KIM-1 (kidney injury molecule 1), MCP-1 (monocyte chemoattractant protein-1), and B2M (beta 2-microglobulin) in healthy term neonates. MATERIAL AND METHODS In the study, we included 80 healthy term neonates - 40 females and 40 males. We collected the neonates' urine on their first day of life. Urinary concentrations of calbindin, clusterin, KIM-1, MCP-1, and B2M were assessed using an immunoassay for kidney toxicology research. Because dilution of the urine affects the concentrations of urinary biomarkers, we normalized them to the concentration of urinary creatinine (Cr) and present them as biomarker/Cr ratios. RESULTS We obtained the following values of the assessed biomarker/Cr ratios (median [Q1-Q3]): calbindin/Cr.: 197.04 (56.25-595.17), KIM-1/Cr: 0.09 (0.04-0.18), MCP-1/Cr: 0.05 (0.02-0.14), B2M/Cr: 126.12 (19.03-342.48), GST-pi/Cr in boys: 1.28 (0.46-3.77), GST-pi/Cr in girls: 8.66 (2.51-27.82), clusterin/Cr: 4.55 (1.79-12.97) ng/mg Cr. CONCLUSIONS We showed the urinary levels of calbindin, clusterin, GST-pi, KIM-1, MCP-1, B2M in white, West Slavic, healthy term neonates. We found that in there is an association between female sex and a higher urinary GST-pi excretion, but urinary excretion of calbindin, clusterin, KIM-1, MCP-1, and B2M is sex-independent. The urinary levels of the assessed biomarkers do not depend on the method of delivery.

A comparative study on the effect of limestone particle size on performance, ileal digestibility of calcium and phosphorus, and bone characteristics in broilers and pullets.

1. The effects of limestone particle size on growth performance, gastrointestinal tract (GIT) traits, ileal morphology, duodenal gene expression of calbindin, apparent ileal digestibility coefficients (AIDC) of calcium (Ca) and phosphorus (P) and tibia characteristics in broilers and pullets were assessed in broilers and pullets. These birds have different growth rates and likely different responses to parameters, such as particle size.2. A total of 240 chicks aged one day, 120 Ross 308 female broilers, and 120 Hy-Line pullets were allocated randomly into four treatments in a 2 × 2 factorial arrangement with two bird types (broilers vs. pullets) and two limestone particle sizes (<0.5 mm versus 1-2 mm) to give six replicates containing 10 chicks in each from 1 to 21 d of age.3. Feed intake and weight gain were greater (P < 0.001) and feed per gain (FCR) was better (P < 0.001) in broilers compared to pullets from 1 to 21 d of age. Greater villus width (P < 0.01), villus height (P < 0.001) and crypt depth (P < 0.01) were seen for broilers compared to pullets.4. Pullets fed coarse Ca particles had higher calbindin gene expression at 21 d of age (P = 0.05). Both AIDC of Ca and P were higher (P < 0.001) in broilers compared to pullets. The AIDC of Ca from 0.463 to 0.516 was increased (P < 0.05) by feeding coarse limestone particles. A significant interaction was found between bird type and limestone particle size (P < 0.01), where pullets fed coarse Ca particles had higher bone P concentration in tibia than broilers.5. Broilers had better ileum absorptive capacity and growth performance compared to pullets. The AIDC of Ca and P was higher in broilers than in pullets. Increased limestone particle size elevated villus height, AIDC of Ca and concentration of P in the tibia.

[Expression changes of RNA m6A regulators in mouse cerebellum affected by hypobaric hypoxia stimulation].

Objective: To investigate the role of RNA m6A methylation in mediating cerebellar dysplasia through analyzing the phenotypes of the mouse cerebella and the expression of several key m6A regulators upon hypobaric hypoxia treatment. Methods: Five-day old C57/BL6 mice were exposed to hypobaric hypoxia for 9 days. The status of mouse cerebellar development was analyzed by comparing the body weights, brain weights and histological features. Immunostaining of cell-type-specific markers was performed to analyze the cerebellar morphology. Real-time PCR, Western blot and immunohistochemical staining were performed to detect the expression of key m6A regulators in the mouse cerebella. Results: Compared with the control, the body weights, brain weights and cerebellar volumes of hypobaric hypoxic mice were significantly reduced (P<0.01). The expression of specific markers in different cells, including NeuN (mature neuron), Calbindin-D28K (Purkinje cell) and GFAP (astrocyte), was decreased in hypobaric hypoxic mouse cerebella (P<0.01), accompanied with disorganized cellular structure. The expression of methyltransferase METTL3 was significantly down-regulated in the cerebella of hypobaric hypoxic mice (P<0.05). Conclusions: Hypobaric hypoxia stimulation causes mouse cerebellar dysplasia, with structural abnormalities in mature granular neurons, Purkinje cells and astrocytes. Expression of METTL3 is decreased in hypobaric hypoxic mice cerebellum compared with that of normobaric normoxic mice, suggesting that its mediated RNA m6A methylation may play an important role in hypobaric hypoxia-induced mouse cerebellar dysplasia.

Histological and Immunohistochemical Investigation of the Cerebellum in Porcupine and Guinea Pig.

The present study was designed to investigate the cerebellum histology and immunohistochemistry in porcupine (Hystrix cristata) and guinea pig (Cavia porcellus). Two adult porcupines and two adult guinea pigs were used. For general histology, crystal violet and Luxol fast blue stains were applied. For immunohistochemistry, myelin-associated glycoprotein (MAG), neurofilament 200 (NF200), calbindin D-28K, and glial fibrillary-associated protein (GFAP) were investigated. The cerebellar cortex in both species was composed of three cellular layers: molecular, granular, and Purkinje cell (PC) layers. Purkinje cells in the porcupine showed a purple-colored and dark blue-colored cytoplasm in reaction to the crystal violet and Luxol fast blue staining, respectively. In the guinea pig, PC has a uniform reaction to the Luxol fast blue with dark-blue-colored cytoplasm. However, in response to the crystal violet, some PC with dark-purple cytoplasm showed stronger reaction than other PC which showed light-purple cytoplasm. The PC layer in some folia of the porcupine cerebellum was composed of 2-3 layers. The expression rates of calbindin D-28K, MAG, GFAP, and NF200 in the porcupine cerebellum were determined to be 19%, 42.5%, 62%, and 30%, respectively. These values were determined to be 27%, 34%, 43.5%, and 31.5%, respectively, in the guinea pig cerebellum.

Potential Neuroprotective Role of Calretinin-N18 and Calbindin-D28k in the Retina of Adult Zebrafish Exposed to Different Wavelength Lights.

The incidence rates of light-induced retinopathies have increased significantly in the last decades because of continuous exposure to light from different electronic devices. Recent studies showed that exposure to blue light had been related to the pathogenesis of light-induced retinopathies. However, the pathophysiological mechanisms underlying changes induced by light exposure are not fully known yet. In the present study, the effects of exposure to light at different wavelengths with emission peaks in the blue light range (400-500 nm) on the localization of Calretinin-N18 (CaR-N18) and Calbindin-D28K (CaB-D28K) in adult zebrafish retina are studied using double immunofluorescence with confocal laser microscopy. CaB-D28K and CaR-N18 are two homologous cytosolic calcium-binding proteins (CaBPs) implicated in essential process regulation in central and peripheral nervous systems. CaB-D28K and CaR-N18 distributions are investigated to elucidate their potential role in maintaining retinal homeostasis under distinct light conditions and darkness. The results showed that light influences CaB-D28K and CaR-N18 distribution in the retina of adult zebrafish, suggesting that these CaBPs could be involved in the pathophysiology of retinal damage induced by the short-wavelength visible light spectrum.

The Co-Expression Pattern of Calcium-Binding Proteins with γ-Aminobutyric Acid and Glutamate Transporters in the Amygdala of the Guinea Pig: Evidence for Glutamatergic Subpopulations.

The amygdala has large populations of neurons utilizing specific calcium-binding proteins such as parvalbumin (PV), calbindin (CB), or calretinin (CR). They are considered specialized subsets of γ-aminobutyric acid (GABA) interneurons; however, many of these cells are devoid of GABA or glutamate decarboxylase. The neurotransmitters used by GABA-immunonegative cells are still unknown, but it is suggested that a part may use glutamate. Thus, this study investigates in the amygdala of the guinea pig relationships between PV, CB, or CR-containing cells and GABA transporter (VGAT) or glutamate transporter type 2 (VGLUT2), markers of GABAergic and glutamatergic neurons, respectively. The results show that although most neurons using PV, CB, and CR co-expressed VGAT, each of these populations also had a fraction of VGLUT2 co-expressing cells. For almost all neurons using PV (~90%) co-expressed VGAT, while ~1.5% of them had VGLUT2. The proportion of neurons using CB and VGAT was smaller than that for PV (~80%), while the percentage of cells with VGLUT2 was larger (~4.5%). Finally, only half of the neurons using CR (~53%) co-expressed VGAT, while ~3.5% of them had VGLUT2. In conclusion, the populations of neurons co-expressing PV, CB, and CR are in the amygdala, primarily GABAergic. However, at least a fraction of neurons in each of them co-express VGLUT2, suggesting that these cells may use glutamate. Moreover, the number of PV-, CB-, and CR-containing neurons that may use glutamate is probably larger as they can utilize VGLUT1 or VGLUT3, which are also present in the amygdala.

A Novel Early Life Stress Model Affects Brain Development and Behavior in Mice.

Early life stress (ELS) in developing children has been linked to physical and psychological sequelae in adulthood. In the present study, we investigated the effects of ELS on brain and behavioral development by establishing a novel ELS model that combined the maternal separation paradigm and mesh platform condition. We found that the novel ELS model caused anxiety- and depression-like behaviors and induced social deficits and memory impairment in the offspring of mice. In particular, the novel ELS model induced more enhanced depression-like behavior and memory impairment than the maternal separation model, which is the established ELS model. Furthermore, the novel ELS caused upregulation of arginine vasopressin expression and downregulation of GABAergic interneuron markers, such as parvalbumin (PV), vasoactive intestinal peptide, and calbindin-D28k (CaBP-28k), in the brains of the mice. Finally, the offspring in the novel ELS model showed a decreased number of cortical PV-, CaBP-28k-positive cells and an increased number of cortical ionized calcium-binding adaptors-positive cells in their brains compared to mice in the established ELS model. Collectively, these results indicated that the novel ELS model induced more negative effects on brain and behavioral development than the established ELS model.

Sialyltransferase Mutations Alter the Expression of Calcium-Binding Interneurons in Mice Neocortex, Hippocampus and Striatum.

Gangliosides are major glycans on vertebrate nerve cells, and their metabolic disruption results in congenital disorders with marked cognitive and motor deficits. The sialyltransferase gene St3gal2 is responsible for terminal sialylation of two prominent brain gangliosides in mammals, GD1a and GT1b. In this study, we analyzed the expression of calcium-binding interneurons in primary sensory (somatic, visual, and auditory) and motor areas of the neocortex, hippocampus, and striatum of St3gal2-null mice as well as St3gal3-null and St3gal2/3-double null. Immunohistochemistry with highly specific primary antibodies for GABA, parvalbumin, calretinin, and calbindin were used for interneuron detection. St3gal2-null mice had decreased expression of all three analyzed types of calcium-binding interneurons in all analyzed regions of the neocortex. These results implicate gangliosides GD1a and GT1b in the process of interneuron migration and maturation.

Mineralocorticoid receptor blockade with spironolactone has no direct effect on plasma IL-17A and injury markers in urine from kidney transplant patients.

Kidney transplantation is associated with increased risk of cardiovascular morbidity. Interleukin (IL)-17A mediates kidney injury. Aldosterone promotes T helper 17 lymphocyte differentiation and IL-17A production through the mineralocorticoid receptor. In this exploratory, post hoc substudy, it was hypothesized that a 1-yr intervention with the mineralocorticoid receptor antagonist spironolactone lowers IL-17A and related cytokines and reduces epithelial injury in kidney transplant recipients. Plasma and urine samples were obtained from kidney transplant recipients from a double-blind randomized clinical trial testing spironolactone (n = 39) versus placebo (n = 41). Plasma concentrations of cytokines interferon-γ, IL-17A, tumor necrosis factor-α, IL-6, IL-1ß, and IL-10 were determined before and after 1-yr treatment. Urine calbindin-to-creatinine, clusterin-to-creatinine, kidney injury molecule-1-to-creatinine, osteoactivin-to-creatinine, trefoil factor 3 (TFF3)-to-creatinine, and VEGF-to-creatinine ratios were analyzed. Blood pressure and plasma aldosterone concentration at inclusion did not relate to plasma cytokines and injury markers expect for urine TFF3-to-creatinine ratios that correlated positively to blood pressure. None of the cytokines changed in plasma after spironolactone intervention. Plasma IL-17A increased in the placebo-treated group. Spironolactone induced an increase in plasma K+ (0.4 ± 0.4 mmol/L). This increase did not correlate with plasma IL-17A or urine calbindin and TFF3 changes. Ongoing treatment at inclusion with angiotensin-converting enzyme inhibitor and/or ANG II receptor blockers was not associated with changed levels of IL-17A and injury markers and had no effect on the response to spironolactone. Urinary calbindin and TFF3 decreased in the spironolactone-treated group with no difference in between-group analyses. In conclusion, irrespective of ongoing ANG II inhibition, spironolactone has no effect on plasma IL-17A and related cytokines or urinary injury markers in kidney transplant recipients.NEW & NOTEWORTHY The mineralocorticoid receptor antagonist spironolactone had no direct anti-inflammatory effects on prohypertensive interleukin-17A or distal nephron epithelial injury markers in kidney transplant recipients.

Identification of lung innervating sensory neurons and their target specificity.

Known as the gas exchange organ, the lung is also critical for responding to the aerosol environment in part through interaction with the nervous system. The diversity and specificity of lung innervating neurons remain poorly understood. Here, we interrogated the cell body location and molecular signature and projection pattern of lung innervating sensory neurons. Retrograde tracing from the lung coupled with whole tissue clearing highlighted neurons primarily in the vagal ganglia. Centrally, they project specifically to the nucleus of the solitary tract in the brainstem. Peripherally, they enter the lung alongside branching airways. Labeling of nociceptor Trpv1+ versus peptidergic Tac1+ vagal neurons showed shared and distinct terminal morphology and targeting to airway smooth muscles, vasculature including lymphatics, and alveoli. Notably, a small population of vagal neurons that are Calb1+ preferentially innervate pulmonary neuroendocrine cells, a demonstrated airway sensor population. This atlas of lung innervating neurons serves as a foundation for understanding their function in lung.

The retrosplenial cortex of Carollia perspicillata, Seba's short-tailed fruit bat.

Retrosplenial cortex (RSC) is a brain region involved in critical cognitive functions including memory, planning, and spatial navigation and is commonly affected in neurodegenerative diseases. Subregions of RSC are typically described as Brodmann areas 29 and 30, which are defined by cytoarchitectural features. Using immunofluorescence, we studied the distributions of neurons immunoreactive for NeuN, latexin, and calcium binding proteins (calbindin, calretinin, and parvalbumin) in RSC of Carollia perspicillata, Seba's short-tailed fruit bat. We observed that latexin was specifically present in areas 29a and 29b but not 29c and 30. We further identified distribution patterns of calcium binding proteins that group areas 29a and 29b separately from areas 29c and 30. We conclude first that latexin is a useful marker to classify subregions of RSC and second that these subregions contain distinct patterns of neuronal immunoreactivity for calcium binding proteins. Given the long lifespan of Carollia, bat RSC may be a useful model in studying age-related neurodegeneration.

Form-deprivation myopia downregulates calcium levels in retinal horizontal cells in mice.

The process of eye axis lengthening in myopic eyes is regulated by multiple mechanisms in the retina, and horizontal cells (HCs) are an essential interneuron in the visual regulatory system. Wherein intracellular Ca2+ plays an important role in the events involved in the regulatory role of HCs in the retinal neural network. It is unknown if intracellular Ca2+ regulation in HCs mediates changes in the retinal neural network during myopia progression. We describe here a novel calcium fluorescence indicator system that monitors HCs' intracellular Ca2+ levels during form-deprivation myopia (FDM) in mice. AAV injection of GCaMP6s, as a protein calcium sensor, into a Gja10-Cre mouse monitored the changes in Ca2+signaling in HC that accompany FDM progression in mice. An alternative Gja10-Cre/Ai96-GCaMP6s mouse model was created by cross mating Gja10-Cre with Ai96 mice. Immunofluorescence imaging and live imaging of the retinal cells verified the identity of these animal models. Changes in retinal horizontal cellular Ca2+ levels were resolved during FDM development. The numbers of GCaMP6s and the proportion of HCs were tracked based on profiling changes in GCaMP6s+calbindin+/calbindin+ coimmunostaining patterns. They significantly decreased more after either two days (P < 0.01) or two weeks (P < 0.001) in form deprived eyes than in the untreated fellow eyes. These decreases in their proportion reached significance only in the retinal central region rather than also in the retinal periphery. A novel approach employing a GCaMP6s mouse model was developed that may ultimately clarify if HCs mediate Ca2+ signals that contribute to controlling FDM progression in mice. The results indicate so far that FDM progression is associated with declines in HC Ca2+ signaling activity.

Regulation of renal calbindin expression during cisplatin-induced kidney injury.

Since the discovery of calbindin release into the urine during renal injury, there has been growing interest in the utility of this protein as a biomarker of nephrotoxicity. However, little is known about the intrarenal regulation of the release and expression of this calcium-regulating protein during kidney injury. We sought to characterize the time-dependent expression and excretion of the protein calbindin in the distal tubule in comparison to kidney injury molecule-1 (Kim-1), a protein in the proximal tubule, in mice treated with cisplatin. Urine, blood, and kidneys were collected from male C57BL/6 mice treated with vehicle or cisplatin (20 mg/kg ip). Urinary concentrations of calbindin and Kim-1 were elevated by 11.6-fold and 2.5-fold, respectively, within 2 days after cisplatin. Circulating creatinine and blood urea nitrogen levels increased in cisplatin-treated mice by 3 days, confirming the development of acute kidney injury. Time-dependent decreases in intrarenal calbindin protein were observed on Days 3 and 4 and a 200-fold upregulation of calbindin (CALB1) and KIM-1 messenger RNAs (mRNAs) was observed on Day 3. These data suggest that early loss of calbindin protein into the urine along with declines in renal calbindin levels initiates a compensatory induction of mRNA expression at later time points (Days 3 and 4). Understanding the regulation of calbindin during cisplatin nephrotoxicity further enhances its utility as a potential urinary biomarker of kidney damage. The results of the current study support the combined use of a proximal (Kim-1) and distal tubule (calbindin) marker to phenotype acute kidney injury secondary to cisplatin administration.

Markers of kidney tubular and interstitial injury and function among sugarcane workers with cross-harvest serum creatinine elevation.

OBJECTIVES: Serum creatinine (SCr) is a routine marker of kidney injury but also increases with dehydration and muscular work. This study was to elucidate whether increase in SCr is associated with more specific markers of kidney tubular and interstitial injury and function, during prolonged heat stress among workers at high risk of chronic kidney disease of non-traditional origin (CKDnt). METHODS: Urine monocyte chemoattractant protein-1 (MCP-1), kidney injury molecule-1 (KIM-1), calbindin, glutathione S-transferase-π (GST-π), clusterin, interleukin 18 and albumin, fractional excretion of potassium (FEK), blood haemoglobin, serum potassium, ferritin and erythropoietin were measured before and after harvest in a sample of 30 workers with a ≥0.3 mg/dL SCr increase across harvest (cases), and 53 workers with stable SCr (controls). RESULTS: Urine MCP-1 (p for differential cross-harvest trend <0.001), KIM-1 (p=0.002), calbindin (p=0.02), GST-π (p=0.04), albumin (p=0.001) and FEK (p<0.001) increased in cases, whereas blood haemoglobin (p<0.001) and serum erythropoietin (p<0.001) decreased. CONCLUSION: Several markers of tubular and interstitial injury and function changed as SCr increased across a harvest season, supporting the use of SCr as an indicator of kidney injury in physically active workers regularly exposed to heat stress. Repeated injury similar to that described here, and continued work under strenuous and hot conditions with similarly elevated injury markers is likely to worsen and possibly initiate CKDnt.

Identifying Amygdala-Like Territories in Scyliorhinus canicula (Chondrichthyan): Evidence for a Pallial Amygdala.

To identify the putative amygdalar complex in cartilaginous fishes, our first step was to obtain evidence that supports the existence of a pallial amygdala in the catshark Scyliorhinus canicula, at present the prevailing chondrichthyan model in comparative neurobiology and developmental biology. To this end, we analyzed the organization of the lateral walls of the telencephalic hemispheres of adults, juveniles, and early prehatching embryos by immunohistochemistry against tyrosine hydroxylase (TH), somatostatin (SOM), Pax6, serotonin (5HT), substance P (SP), and Met-enkephalin (MetEnk), calbindin-28k (CB), and calretinin (CR), and by in situ hybridization against regulatory genes such as Tbr1, Lhx9, Emx1, and Dlx2. Our data were integrated with those available from the literature related to the secondary olfactory projections in this shark species. We have characterized two possible amygdalar territories. One, which may represent a ventropallial component, was identified by its chemical signature (moderate density of Pax6-ir cells, scarce TH-ir and SOM-ir cells, and absence of CR-ir and CB-ir cells) and gene expressions (Tbr1 and Lhx9 expressions in an Emx1 negative domain, as the ventral pallium of amniotes). It is perhaps comparable to the lateral amygdala of amphibians and the pallial amygdala of teleosts. The second was a territory related to the pallial-subpallial boundary with abundant Pax6-ir and CR-ir cells, and 5HT-ir, SP-ir, and MetEnk-ir fibers capping dorsally the area superficialis basalis. This olfactory-related region at the neighborhood of the pallial-subpallial boundary may represent a subpallial amygdala subdivision that possibly contains migrated cells of ventropallial origin.

Identification of some calcium binding proteins and neural cell markers in rat testis and epididymis during postnatal development.

Calcium-binding proteins (CaBPs) have an essential role in male reproduction by modulating calcium ion metabolism. Although the brain and testis are structurally and functionally different, they show a high degree of transcriptomic and proteomic similarities. The purpose of the present study was to explore some CaBPs (Iba-1, Calbindin, Calretinin and Parvalbumin) and neural cell markers (CNPase, NG2 and Drebrin) expression in rat testis and epididymis during postnatal periods by using immunohistochemistry. Iba-1, calbindin, calretinin, parvalbumin, CNPase, NG2 and drebrin were expressed in the epididymal epithelium in each postnatal period. Iba-1 and calbindin expression showed stage-dependent expression in spermatids. CaBPs and neural cell markers showed a positive reaction in Leydig cells in the postpubertal and mature periods. Sertoli cells, gonocytes, spermatogonium, and peritubular myoid cells showed heterogeneity in the expression of CaBPs and nerve markers throughout postnatal development. Interestingly, CNPase, NG2 and drebrin were positive in spermatocytes, spermatids, and sperm. Expression dynamics of calcium-binding proteins and nerve markers showed differences in germ cells and somatic cells during postnatal development. The expression of these proteins in the testis and epididymis supports that they may have important roles in reproductive physiology.