A reassessment of spinal cord pathology in severe infantile spinal muscular atrophy: Reassessment of spinal cord pathology.

AIMS: Spinal muscular atrophy (SMA) is a life-limiting paediatric motor neuron disease characterised by lower motor neuron loss, skeletal muscle atrophy and respiratory failure, if untreated. Revolutionary treatments now extend patient survival. However, a limited understanding of the foundational neuropathology challenges the evaluation of therapeutic success. As opportunities to study treatment-naïve tissue decrease, we have characterised spinal cord pathology in severe infantile SMA using gold-standard techniques, providing a baseline to measure treatment success and therapeutic limitations. METHODS: Detailed histological analysis, stereology and transmission electron microscopy were applied to post-mortem spinal cord from severe infantile SMA patients to estimate neuron number at the end of life; characterise the morphology of ventral horn, lateral horn and Clarke's column neuron populations; assess cross-sectional spinal cord area; and observe myelinated white matter tracts in the clinically relevant thoracic spinal cord. RESULTS: Ventral horn neuron loss was substantial in all patients, even the youngest cases. The remaining ventral horn neurons were small with abnormal, occasionally chromatolytic morphology, indicating cellular damage. In addition to ventral horn pathology, Clarke's column sensory-associated neurons displayed morphological features of cellular injury, in contrast to the preserved sympathetic lateral horn neurons. Cellular changes were associated with aberrant development of grey and white matter structures that affected the overall dimensions of the spinal cord. CONCLUSIONS: We provide robust quantification of the neuronal deficit found at the end of life in SMA spinal cord. We question long-accepted dogmas of SMA pathogenesis and shed new light on SMA neuropathology out with the ventral horn, which must be considered in future therapeutic design.

[Histological and ultrastructural analysis of biopsy specimens of donor heart under conditions of extended period of pharmaco-cold ischaemia]. / Gistologicheskii i ul'tramikroskopicheskii analiz bioptatov donorskogo serdtsa v usloviyakh prodlennogo perioda farmakokholodovoi ishemii.

OBJECTIVE: At the histological and ultramicroscopic level, compare biopsy specimens of donor heart under standard (up to 240 min) and extended (more than 240 min) periods of pharmaco-cold preservation. MATERIAL AND METHODS: Biopsy specimens of the left atrium of donor hearts: group 1 - 8 samples after transportation with pharmaco-cold preservation of the graft in Bretschneider solution (Dr. Franz Köhler Chemie GmbH, Germany) up to 240 min, (Me 140), and group 2 - 5 samples after an extended pharmaco-cold period (more than 240 min; Me 375) were examined using light microscopy of semi-thin sections and transmission electron microscopy, followed by stereological and statistical analysis. RESULTS: A comparative study of the myocardium of donor hearts revealed stereotypical dystrophic changes in cardiomyocytes. Semi-thin sections demonstrated a mosaic pattern of myocardial parenchyma in both groups, caused by contracture and less pronounced lytic changes in myocytes, which were accompanied by stromal edema without statistically significant differences according to stereological studies. Ultrathin sections of the perinuclear zones of cardiomyocytes visualized reduction and focal damage to myofibrils and mitochondria in combination with pronounced autophagy; at the same time, with a shorter duration of the pharmaco-cold period, the stereological indicators of cardiomyocyte organelles indicated a relatively better supply of myofibrils with mitochondria. CONCLUSION: The results obtained suggest a sufficiently high degree of preservation of the tissue and ultrastructural organization of donor hearts with prolonged (more than 240 min) pharmaco-cold ischemia to restore adequate cardiac activity after heart transplantation.

Stereological study of organelle distribution in human mature oocytes.

The ultrastructure of human oocytes has been described only qualitatively. To offer a precise organelle spatial distribution and organelle volume during the main maturation stages, we previously conducted stereological studies on prophase-I (GV) and metaphase-I (MI) oocytes, and here we present results on metaphase-II (MII) oocytes. Five donor oocytes from different donors were processed for transmission electron microscopy, and quantification of organelle distribution was performed using point-counting stereology. Statistical tests compared the means of the relative volumes occupied by organelles among oocyte regions. The most abundant organelles were elements of the smooth endoplasmic reticulum (SER), such as SER small vesicles, SER medium vesicles, SER large vesicles and SER isolated tubules, along with mitochondria, followed by SER tubular aggregates, cortical vesicles and lysosomes. Significant differences between oocyte regions were found for lysosomes, cortical vesicles and SER large vesicles. Comparisons of MII oocytes to previous findings in GV and MI oocytes evidenced specific patterns of organelle distribution and relative volumes. This final evaluation thus enables to track organelle spatial reorganization across oocyte stages, which, in addition to gathered knowledge, may be useful to assist in improvements of stimulation protocols, in-vitro maturation media and cryopreservation techniques.

Ultrastructural analysis of lamellar bodies in type II alveolar epithelial cells in the human lung.

Pulmonary surfactant is produced by type II alveolar epithelial cells (AEC2) and stored in lamellar bodies (LBs) prior to secretion. Here, we characterize AEC2 and their LBs in the human lung ultrastructurally and quantitatively. Five human lungs were analyzed by transmission electron microscopy, serial section electron tomography and stereology. A human lung contained about 24 billion AEC2 with a mean size of about 650 µm³. The number of AEC2 as well as the total volume of LBs per lung, about 1.9 mL, strongly correlated with total lung volume. A single AEC2 contained an LB volume of about 74 µm³. This amount was packed in about 324 LBs with a mean size of 0.24 µm³. Three morphologically distinct subpopulations of LBs were identified: 1.) isolated LBs which make up the majority (average 300 per AEC2), 2.) LBs connected to each other via pores (average 23 per AEC2), and 3.) LBs connected to the plasma membrane via a fusion pore (average 1 per AEC2). Along this sequence of subpopulations, the mean size of LBs increased. LBs that are connected either with each other or to the plasma membrane contained about 14% of an AEC2´s LB volume. This is in line with the concept of an intermediate surfactant pool, stored in LBs either directly or indirectly connected to the plasma membrane. In summary, this study provides quantitative reference data on surfactant-storing LBs in AEC2 as well as morphological evidence for an intermediate surfactant pool in the human lung.

Stereologic consequences of iatrogenic collapse: The morphology of adenocarcinoma in situ overlaps with invasive patterns. Proposal for a necessary modified classification of pulmonary adenocarcinomas.

Recognizing non-invasive growth patterns is necessary for correct diagnosis, invasive size determination and pT-stage in resected non-small cell lung carcinoma. Due to iatrogenic collapse after resection, the distinction between adenocarcinoma in-situ (AIS) and invasive adenocarcinoma may be difficult. The aim of this study is to investigate the complex morphology of non-mucinous non-invasive patterns of AIS in resection specimen with iatrogenic collapse, and to relate this to follow-up. The effects of iatrogenic collapse on the morphology of collapsed AIS were simulated in a mathematical model. Three dimensional related criteria applied in a modified classification, using also cytokeratin 7 and elastin as additional stains, in two independent retrospective cohorts of primary pulmonary adenocarcinomas ≤3 cm resection specimen with available follow-up information. The model demonstrated that infolding of alveolar walls occurs during iatrogenic collapse and lead to a significant increase in tumor cell heights in maximal collapse areas, compared to less collapsed areas. The morphology of infolded AIS overlaps with patterns described as papillary and acinar adenocarcinoma according to the WHO classification, necessitating an adaptation. The modified classification incorporates recognition of iatrogenic and biologic collapse, tangential cutting effect true invasion and surrogate markers of invasion i.e. grey zone, covering a multilayering falling short of micropapillary, cribriform and solid alveolar filling growth. The use of elastin and CK7 staining aids in the morphologic recognition of iatrogenic collapsed AIS and the distinction from invasive adenocarcinoma. Out of a total of 70 resection specimens 1 case was originally classified as AIS and 9 were reclassified as iatrogenic collapsed AIS. Patients with collapsed AIS showed a 100 % recurrence-free survival after a mean follow-up time of 69.5 months. With the current WHO classification, AIS is overdiagnosed as invasive adenocarcinoma due to infolding. The modified classification facilitates the diagnosis of AIS.

The Protective Effect of GnRH Agonist Triptorelin on the Histomorphometric Parameters of the Utero-ovarian Tissue in the Doxorubicin- and Cyclophosphamide-treated Mice.

One of the common side effects of chemotherapy drugs is ovarian failure and uterine dysfunction, which can occur after the administration of doxorubicin and/or cyclophosphamide. In clinics, gonadotropin-releasing hormone agonists (GnRHa) are used to modulate the toxic effect of chemotherapy and intercept infertility with some controversy and limited histological knowledge. This study aimed to evaluate the serological and histological features of protective effects of triptorelin, (GnRHa), on utero-ovarian tissue in the mice treated with cyclophosphamide and/or doxorubicin. Forty-eight female BALB/c mice were randomly divided into 8 groups as follows: Group I: normal saline; Group II: triptorelin; Group III: cyclophosphamide; Group IV: doxorubicin; Group V: cyclophosphamide + doxorubicin; and Groups VI, VII, and VIII: after injection of cyclophosphamide, doxorubicin, or cyclophosphamide + doxorubicin, administration of triptorelin (1 mg/kg; intraperitoneally) for 15 consecutive days, respectively. On the 21st day, the ovaries and uterine horns were dissected and weighed. Then, tissue processing and staining were performed for further histological and stereological studies. Triptorelin treatment in the damaged groups significantly increased the number of primordial and pre-antral follicles and granulosa cells. It decreased the number of atretic follicles compared to cyclophosphamide and/or doxorubicin-treated groups (P < 0.05). Triptorelin also significantly improved the volume of the ovary, cortex, medulla, oocytes in the primordial and antral follicles, uterus, endometrium, myometrium, uterine glands, and endometrial blood vessels in the damaged groups (P < 0.05). Triptorelin treatment prevents the destructive effects of cyclophosphamide and/or doxorubicin on utero-ovarian tissue.

Does coenzyme Q10 supplementation protect spermatogenesis in ciprofloxacin-induced rat testes?

Objective: Ciprofloxacin (CPFX) is frequently prescribed by fertility specialists and urologists to manage infections in male reproductive organs. However, it is toxic to the testicles and can lead to infertility. Dietary antioxidants are known to protect the testis from damage. This study aimed to investigate the effects of coenzyme Q10 (CoQ10) on the adverse side effects of CPFX using stereological methods. Methods: Sixty rats were divided into six groups: control (distilled water), CoQ10 (10 mg/kg/day), and low-dose (103 mg/kg/day) and high-dose (206 mg/kg/day) of CPFX (LD-CPFX, HD-CPFX) with or without CoQ10 consumption. The treatments lasted for 45 days. Sperm count, serum testosterone levels, and testicular parameters were evaluated. Results: Significant decreases in sperm count, motility, normal morphology, viability, and testosterone levels were observed in the LD-CPFX (p<0.003) and HD-CPFX- treated rats (p=0.0001) compared to the control groups. A 10% to 36% reduction in the volume of seminiferous tubules, tubular epithelium, and tubule length was noted in LD-CPFX (p<0.01) and HD-CPFX-treated rats (p<0.006), while the volume of the interstitium increased by 25% to 28% in LD-CPFX (p=0.03) and HD-CPFX (p=0.008) groups. The number of cells, including spermatogonia, spermatocytes, spermatids, Sertoli cells, and Leydig cells, decreased by 36% to 75% in the testes exposed to LD-CPFX (p<0.04) and HD-CPFX (p<0.01), compared to the control groups. However, these changes normalized in rats that received CoQ10. Conclusion: CPFX exposure for 45 days, regardless of the dose, has detrimental effects on testicular parameters. CoQ10 can prevent CPFX-induced testicular structural impairments.

Tyrosine hydroxylase expression and neuronal loss in the male and female adolescent ventral tegmental area.

Adolescence is a critical period of development characterized by numerous behavioral and neuroanatomical changes. While studies of adolescent neurodevelopment typically compare adolescent age groups with young adults, there are fewer studies that assess developmental trajectories within the adolescent period. In the adolescent prefrontal cortex, some maturational changes take place linearly/chronologically, while others are associated specifically with pubertal onset. The adolescent ventral tegmental area (VTA), a primary source of forebrain dopamine, is relatively understudied during this period. In the present study, dopamine neuron number, total neuron number and tyrosine hydroxylase expression are assessed in the male and female rat VTA at three timepoints: postnatal day(P) 30 (pre-pubertal), P40 (post-pubertal for females, pre-pubertal for males) and P60 (post-pubertal). There was a non-significant trend for a reduction in total VTA neuron number between P30 and P60, but there was a significant reduction in dopamine neuron number across age. The expression of tyrosine hydroxylase did not change with age. However, in a second cohort of subjects, brain tissue was collected pre-pubertal, from recently post-pubertal males and females, and young adults. In this cohort, there was a sex-specific and transient decrease in tyrosine hydroxylase expression in recently post-pubertal males. These results suggest a selective pruning of VTA dopamine cells between early adolescence and young adulthood, while pubertal onset may coincide with a rapid maturation of these neurons. These findings may have implications for psychiatric disorders associated with dopamine dysfunction that tend to manifest during adolescence.

Stereological study of cerebellar morphology in feline fetuses: Insights from the final gestational stage.

This study aimed to conduct a morphoquantitative and stereological evaluation, analyzing the cerebellum of domestic cat fetuses in the latter third of the gestational period. Fetal samples were obtained from a neutering campaign conducted in the municipality of Guarulhos, São Paulo, Brazil. The procedures and protocols used in this work adhere to the guidelines established by the ethics committee of the School of Veterinary Medicine and Animal Science at the University of São Paulo (FMVZ/USP), under the number CEUA 1935251121. The five selected fetuses were fixed in 4 % formaldehyde, and their gestational age was determined by Crown Rump (CR) measurements, followed by an assessment of external characteristics. The cerebella were subjected to the evaluation of morphometric parameters and histological processing using stereology techniques. The obtained means for the cerebellar parameters were as follows: length: 1.0-centimeter, width: 0.54 centimeters, thickness: 0.44 centimeters, and weight: 0.84 g. Using stereology, the following parameters were determined: cerebellar volume, averaging 0.847 cm³; volume density of the cortex: 0.496 or 49 % (molecular layer), 0.0314 or 3.14 % (Purkinje cell layer), 0.232 or 23 % (granular layer), and 0.234 or 23 % (medullary white center). Consequently, the average total volume of the cerebellar cortex is 0.419 cm³ for the molecular layer, 0.026 cm³ for the Purkinje cell layer, 0.196 cm³ for the granular layer, and 0.196 cm³ for the medullary white center. The findings presented here have contributed to an in-depth discussion of the neuro-motor development and cerebellum of domestic cats.

Silymarin mitigates toxic effects of cyclophosphamide on testicular tissue and sperm parameters in mice.

Cyclophosphamide, a chemotherapy drug, increases oxidative stress in sperm and testicular tissue. This study evaluated the effect of silymarin, a potent antioxidant, on the quality of sperm and testicular tissue in mice treated with cyclophosphamide. NMRI adult male mice were divided into four groups: control; cyclophosphamide (intraperitoneal injection, 100 mg/kg, once a week); cyclophosphamide + silymarin; and silymarin (intraperitoneal injection, 200 mg/kg, every other day). After a 35-day treatment period, the caudal region of the epididymis was examined for sperm parameters, the right testis was used for stereological studies, and the left testis was used to assess biochemical factors. The data were statistically analyzed using SPSS software, one-way ANOVA and Tukey's test. In the cyclophosphamide group, there was a significant reduction in the mean total volume of testicular tissue, the average volume of seminiferous tubules and their components, and the average volume of interstitial tissue. Additionally, there was a notable decrease (p < 0.001) in the average number of Leydig cells, Sertoli cells, and sperm parameters. The mean concentration of testosterone hormone (p < 0.05) and total antioxidant capacity (TAC) level (p < 0.01) also significantly decreased, while the malondialdehyde (MDA) level increased significantly (p < 0.05). However, these adverse changes were mitigated in the cyclophosphamide + silymarin group compared to the cyclophosphamide group. Our results showed that silymarin as an antioxidant can mitigate the adverse effects of cyclophosphamide on testicular tissue and sperm parameters.

Placental homogeneity: Characterizing transcriptional variation among equine chorioallantoic locations.

The proper function of the placenta is essential for the health and growth of the fetus and the mother. The placenta relies on dynamic gene expression for its correct and timely development and function. Although numerous studies have identified genes vital for placental functions, equine placental molecular research has primarily focused on single placental locations, in sharp contrast with the broader approach in human studies. Here, we hypothesized that the molecular differences across different regions of the equine placenta are negligible because of its diffuse placental type with a macroscopic homogenous distribution of villi across the placental surface. We compared the transcriptome and stereological findings of the body, pregnant horn, and non-pregnant horn within the equine chorioallantois. Our transcriptomic analysis indicates that the variation between regions of the placenta within individuals is less than the variation observed between individuals. A low number of differentially expressed genes (DEGs) (n = 8) was identified when comparing pregnant and non-pregnant horns within the same placenta, suggesting a remarkable molecular uniformity. A higher number of DEGs was identified when comparing each horn to the body (193 DEGs comparing pregnant horn with body and 207 DEGs comparing non-pregnant horn with body). Genes with a higher expression in the body were associated with processes such as extracellular matrix synthesis and remodeling, which is relevant for placental maturation and placenta-endometrial separation at term and implies asynchrony of these processes across locations. The stereological analysis showed no differences in microcotyledonary density, and width between the locations. However, we observed a greater chorioallantoic thickness in the body and pregnant horn compared to the non-pregnant horn. Overall, our findings reveal a uniform transcriptomic profile across the placental horns, alongside a more distinct gene expression pattern between the uterine body and horns. These regional differences in gene expression suggest a different pace in the placental maturation and detachment among the placental locations.

Prenatal protein malnutrition decreases neuron numbers in the parahippocampal region but not prefrontal cortex in adult rats.

OBJECTIVE: Prenatal protein malnutrition produces anatomical and functional changes in the developing brain that persist despite immediate postnatal nutritional rehabilitation. Brain networks of prenatally malnourished animals show diminished activation of prefrontal areas and an increased activation of hippocampal regions during an attentional task [1]. While a reduction in cell number has been documented in hippocampal subfield CA1, nothing is known about changes in neuron numbers in the prefrontal or parahippocampal cortices. METHODS: In the present study, we used unbiased stereology to investigate the effect of prenatal protein malnutrition on the neuron numbers in the medial prefrontal cortex and the cortices of the parahippocampal region that comprise the larger functional network. RESULTS: Results show that prenatal protein malnutrition does not cause changes in the neuronal population in the medial prefrontal cortex of adult rats, indicating that the decrease in functional activation during attentional tasks is not due to a reduction in the number of neurons. Results also show that prenatal protein malnutrition is associated with a reduction in neuron numbers in specific parahippocampal subregions: the medial entorhinal cortex and presubiculum. DISCUSSION: The affected regions along with CA1 comprise a tightly interconnected circuit, suggesting that prenatal malnutrition confers a vulnerability to specific hippocampal circuits. These findings are consistent with the idea that prenatal protein malnutrition produces a reorganization of structural and functional networks, which may underlie observed alterations in attentional processes and capabilities.

Exploring the epidermal architecture of Dasyprocta prymnolopha: A potential dermatology research model.

The agouti (Dasyprocta prymnolopha) is a medium-sized, wild rodent that is highly rustic and docile. Its size and ease of management make it a viable candidate for an alternative animal model to traditional murine subjects. However, data on the epidermal strata of agoutis are lacking, with significant uncertainties persisting regarding their skin's characterization. This study aimed to describe and quantify the epidermal strata of skin biopsies from male and female agoutis raised in captivity, to further validate the species as a model for dermatological research. Ultrastructural evaluations through atomic force microscopy (AFM) and stereological analyses were conducted, revealing significant differences between the layers of the skin; notably, the dermis exhibited a greater total volume than the epidermis. The findings suggest that the epidermal strata are well-defined, with the volume likely correlating to the size and cellular density of the keratinocytes. Corneodesmosomes and tonofilaments were identified across all epidermal layers, indicating the probable maintenance of anchoring protein activity, even post-cornification of these cells. These results suggest that the agouti may serve as a promising model for dermatological studies, owing to the homogeneity of its cutaneous tissue across different body regions and the distinct volume and morphology of its epithelial stratification, which could enhance the applicability of systematic investigative methods in the future.

Morphology of the Digestive Tube of the Amazonian Freshwater Stingray Potamotrygon wallacei (Elasmobranchii: Potamotrygonidae): A Stereological Approach.

This work aimed to describe and quantify the tissue components of the digestive tube of the neotropical freshwater stingray, Potamotrygon wallacei. For this, conventional histology and stereological methods were used to estimate tissue volume. The volumes of the four fundamental layers and the tissue components in the stomach (cardiac and pyloric) and spiral intestine were also estimated. In the cardiac stomach, the mucosa layer occupies 44.7% of the total volume of the organ wall. The gastric glands are the main components, and these structures alone represent 49.7% of this layer. This large number of gastric glands suggests a high potential for processing food items with a high protein content. The stereological methods were sensitive enough to show a reduction in the volume of the gastric glands from the cardiac region toward the pyloric region. Gastric glands are absent in the pyloric region of the stomach. However, the muscularis becomes thicker towards the pyloric region. The increase in smooth muscle thickness is due to the thickening of the inner muscular layer. This suggests that the role of the pyloric stomach may be related to the mixing of the chyme and assisting its passage to the spiral intestine. In the spiral intestine, data on the volume of the mucosa layer (and epithelial lining) suggest that the spiral valve has a large absorptive area. In several respects, the morphology of the digestive tube of P. wallacei is similar to that of other batoids. However, its slight morphological variations may be related to the habitat specificity of this species.

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.

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.

Protective Action of Curcumin and Alpha-lipoic Acid, Against Experimental Ultraviolet-A/B Induced Dermal-injury in Rats.

The objective of this study was to examine the therapeutic efficacy of curcumin (CUR) and α-lipoic acid (ALA) in mitigating UV-A and UV-B-induced damage (UVAB) in rat dorsal skin. This was achieved through the utilisation of immunohistochemical (TUNEL), biochemical and stereological techniques. The rats in the UVAB, UVAB + CUR, and UVAB + ALA groups were subjected to UVAB irradiation for a period of two hours per day over the course of one month. The UVAB + CUR and UVAB + ALA groups were administered 100 mg/kg/day of curcumin and 100 mg/kg/day of α-lipoic acid via gavage 30 min prior to UVAB irradiation. The CUR group was administered 100 mg/kg/day of curcumin via gavage, while the ALA group received the same dose of α-lipoic acid. A significant change in the volume ratio of the dorsal skin epidermis and dermis was observed in the stereological findings of the rats in the UVAB group. These changes exhibited a favourable progression as a consequence of the CUR and ALA applications. In the UVAB group, TOS and OSI were significantly elevated as a consequence of the rise in oxidative stress. Conversely, the treatment groups demonstrated a notable reduction in TOS and OSI levels. The study also revealed a substantial increase in the number of apoptotic cells within the UVAB group. However, the treatment groups exhibited a significant decline in apoptotic cells. In conclusion, the findings suggest that CUR and ALA possess a protective effect against UVAB-induced skin damage.

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.

Applying the area fraction fractionator (AFF) probe for total volume estimations of somatic, dendritic and axonal domains of the nigrostriatal dopaminergic system in a murine model.

BACKGROUND: The Cavalieri estimator is used for volume measurement of brain and brain regions. Derived from this estimator is the Area Fraction Fractionator (AFF), used for efficient area and number estimations of small 2D elements, such as axons in cross-sectioned nerves. However, to our knowledge, the AFF has not been combined with serial sectioning analysis to measure the volume of small-size nervous structures. NEW METHOD: Using the nigrostriatal dopaminergic system as an illustrative case, we describe a protocol based on Cavalieri's principle and AFF to estimate the volume of its somatic, nuclear, dendritic, axonal and axon terminal cellular compartments in the adult mouse. The protocol consists of (1) systematic random sampling of sites within and across sections in regions of interest (substantia nigra, the nigrostriatal tract, caudate-putamen), (2) confocal image acquisition of sites, (3) marking of cellular domains using Cavalieri's 2D point-counting grids, and 4) determination of compartments' total volume using the estimated area of each compartment, and between-sections distance. RESULTS: The volume of the nigrostriatal system per hemisphere is ∼0.38 mm3, with ∼5 % corresponding to perikarya and cell nuclei, ∼10 % to neuropil/dendrites, and ∼85 % to axons and varicosities. COMPARISON WITH EXISTING METHODS: In contrast to other methods to measure volume of discrete objects, such as the optical nucleator or 3D reconstructions, it stands out for its versatility and ease of use. CONCLUSIONS: The use of a simple quantitative, unbiased approach to assess the global state of a system may allow quantification of compartment-specific changes that may accompany neurodegenerative processes.

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.