Vanadium, an environmental pollutant, is closely associated with neurodegeneration, primarily through oxidative damage and chronic neuroinflammation. While chronic inflammation, including tumour necrosis factor-alpha (TNF-α) upregulation has been implicated in stimulating or exacerbating neuronal damage in vanadium-induced neurotoxicity, the relative cellular specificity and pathogenic mechanisms underlying cellular cytotoxicity leading to their dysfunction and death remains poorly understood. In this study, we investigated chronic inflammatory profiles in vanadium-induced neuropathology, focusing on TNF-α expression and its cellular localization in neurons and glia cells. Four weeks old male BALB/c mice randomly divided into 3 groups were used in 18 months of experiments. Vanadium treated (sodium metavanadate 3mg/kg, intraperitoneally, i.p., 0-18 months), matched controls (sterile water volume matched with vanadium treated i.p., 0-18 months), and withdrawal group (sodium metavanadate 3mg/kg, i.p., 0-3 months, and were withdrawn from treatment). Treatments were done at 72-hour intervals in all groups. Mice were sacrificed and brain tissues collected. Sagittal sections of paraffin-embedded brain tissues were prepared and analyzed using immunofluorescence to probe for microglia (Iba1), astrocytes (GFAP) and neurons (NeuN) expression. Double immunofluorescence labelling was employed to study the immunoreactivity and cellular localization of TNF-α. Mean densitometric scores and stereological data were analyzed using descriptive statistics and ANOVA at α = 0.05. Our data revealed prolonged vanadium exposure for 6 to 18 months induced chronic inflammation, evidenced by functional astrocytic and microglial activation, and progressive increase in TNF-α expression in the frontoparietal cortices, and the dorsal CA1 and CA3 regions. TNF-α immunoreactivities were predominantly seen in astrocytes and neurons, but less in microglia. Double immunolabeling with glial cells (Iba1, GFAP) and neuronal markers (NeuN) showed neuronal degeneration with marked cell loss and functional gliosis at the sites of TNF-α immunoreactivity. The severity of glial activation, TNF-α expression and neuronal loss progressively increased with the duration of vanadium exposure. Notably, these pathologies were significantly attenuated after vanadium withdrawal. Our findings indicate that chronic vanadium neurotoxicity causes neuronal loss through oxidative damage, abnormal glial activation and TNF-mediated cell death.
Sequel to the 2024 highly pathogenic avian influenza (HPAI) virus H5N1 outbreak among cattle in the United States of America, it became imperative to investigate the exposure of Nigerian cattle, a major source of much needed animal protein, to avian influenza virus (AIV). This study adopted a cross-sectional design to evaluate influenza A virus (IAV) exposure among the tested cattle using serological and molecular techniques. We collected 693 blood and 54 milk samples from six states located in the south-western, north-central and north-eastern regions of Nigeria. Of these, 31 blood samples (4.5%) were seropositive for IAV nucleoprotein, whereas all milk samples tested negative. Moreover, the IAV matrix gene was not detected in any of the samples. Our findings showed that the cattle seropositivity was not due to the HPAI H5 exposure. To our knowledge, this represents the first evidence of IAV exposure among cattle in Nigeria. Further research is warranted to identify the risk factors that facilitate intra- and interspecies transmission of IAV within the Nigerian cattle population.
Abstract Objective The Pied Crow (Corvus albus) is a visually guided diurnal corvid widely distributed across sub-Saharan Africa, yet detailed descriptions of its ocular microanatomy remain limited. This study provides a concise histological and immunohistochemical characterization of the retina from an adult male specimen obtained through an ethically approved wildlife surveillance programme. Hematoxylin and eosin staining, Alcian Blue staining, and NeuN immunolabeling were used to document retinal organization and neuronal localization. The objective was to generate baseline morphological data for this species. Results The retina exhibited a well-organized multilayered structure typical of diurnal avian species, supported by a prominent hyaline scleral cartilage plate. The outer nuclear layer contained 3–4 rows of nuclei, consistent with the duplex organization of avian retinas. Total retinal thickness measured approximately 303 μm, with the ganglion cell layer measuring ~ 27 μm. NeuN immunolabeling showed strong nuclear immunoreactivity in the ganglion cell layer and moderate labeling in the inner nuclear layer. NeuN-positive neuronal somata in the ganglion cell layer ranged from 2.4 to 5.8 μm in diameter. These findings provide baseline histological and morphometric reference data for Corvus albus, contributing foundational information for future comparative and functional investigations.
Diazinon is a commonly used organophosphate (OP) insecticide especially in developing countries for the control of insect pests, however, exposure to its toxic impact especially in humans and other non-target species remains an important public health concern. The study aimed to investigate the effect of epigallocatechin -3- gallate (EGCG), abundant in green tea plants on neurobehavioural, biochemical, and pathological changes in the brain of male Wistar rats following exposure to diazinon toxicity. Sixty adult male Wistar rats were acclimatized for seven days and subsequently randomly assigned into six treatment groups as follows: Group I: Control group (0.2 mL distilled water); Group II: Diazinon at 3 mg/kg (1
BACKGROUND:The COVID-19 pandemic of 2020 was unprecedented in its devastating impact on the global economy, public health, travel and tourism, education, sports, religion, and social lives. Studies conducted thereafter on the disease and its causative agent, SARS-CoV-2, have highlighted the need for effective and sustainable public health interventions. METHODS:This study investigated the prevalence and endemicity of SARS-CoV-2 infection in pet dogs using immunochromatography assay (IC) and quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) of their blood, rectal swabs, and nasal swabs in Ibadan, Oyo State, Nigeria between 2022 and 2024. KEY FINDINGS:For the IC, positivity rates of 11.7% (23/197), 85.7% (6/7), and 100% (3/3) were recorded for 2022, 2023 and 2024 while for the RT-qPCR, positivity rates of 37.9% (11/29), 33.3% (2/6) and 100% (3/3) were recorded for 2022, 2023 and 2024. This repeated detection of SARS-CoV-2 in three of the dogs tested over the three-year period suggests continuous shedding of the virus by these animals and indicates endemicity of the virus in the study area. Findings highlight the urgent need for optimized SARS-CoV-2 rapid diagnostic tools tailored for veterinary applications to ensure rapid and reliable detection of the virus, especially in resource-constrained settings. CONCLUSION:Considering the zoonotic nature of SARS-CoV-2 and its potential for mutation into more virulent strains that can be transmissible to humans, the findings of this study have significant implications for public health and implementation of One Health strategies by policymakers, and highlight the need for robust SARS-CoV-2 surveillance in domestic animals to mitigate potential zoonotic risks.
Arboreal environments require specialized adaptations in sensory and neuroendocrine systems for species survival. This study examines the neuroanatomical and histological adaptations of the Gambian Sun squirrel (Heliosciurus gambianus), focusing on structures critical for visual processing, sensorimotor integration, and neuroendocrine regulation in arboreal habitats. Paraffin-embedded eye and brain samples from three male Gambian Sun squirrels captured at the University of Ibadan, Nigeria, were analyzed using standard hematoxylin and eosin and Masson trichrome staining techniques. The cornea displayed a unique undulating cellular arrangement, which may likely enhance visual acuity and protection in densely forested environments. Neuroanatomical examination revealed distinctive features in the median eminence, pineal gland, subcommissural organ, dorsal lateral geniculate nucleus, rostral colliculus, and optic nerve, which support sensorimotor coordination and neuroendocrine functions. These specialized traits enable environmental navigation and survival, emphasizing their role in arboreal adaptation. The findings provide a foundation for comparative studies with other rodents and contribute to understanding evolutionary strategies in tree-dwelling mammals. Additionally, this research offers potential applications in conservation efforts and neurobiological studies, including insights into human neurological functions.
This work was designed to investigate the morphometry and immunohistochemical features of pituitary glands in the African Giant Rats (AGR). Adult and juvenile AGR were sacrificed and their brains harvested, and the pituitary glands were carefully dissected. The weight, length and width of brains and pituitary glands were subsequently measured. Sections were prepared and stained using Haematoxylin and Eosin (H&E), Cresyl-violet and periodic-acid-Schiff (PAS) for histological analysis. Immunohistochemical analysis was carried out with Glial-Fibrillary-Acidic-Protein (GFAP) and Ionized-Calcium-Binding-Adapter-Molecule 1 (Iba1). Grossly, the AGR pituitary gland is a somehow laterally extended, saddle-shaped organ that is dorso-ventrally flattened. The gray-coloured adenohypophysis (anterior-pituitary lobe) was bigger in size than the whitish neurohypophysis (posterior-pituitary lobe) on physical examination. Histometrically, the adenohypophyseal length was noticeably greater than that of neurohypophysis in both juvenile and adult. Similarly, the adenohypophyseal and neurohypophyseal width in adult were found to be more than that of juvenile. Also, the histological staining of the neurohypophysis and adenohypophysis were distinct. In the neurohypophysis, fibrous and protoplasmic pituicytes were observed among fibres and Herring-bodies. Chromophils and chromophobes were identified in the adenohypophysis and melanotrophs in the intermediate lobe. Immunohistochemistry showed pituicytes in the neurohypophysis, which was positive with GFAP-antibody. With Iba1-antibody, the neurohypophysis expressed a stronger positive immunolabelling to microglia as compared to macrophages in the adenohypophysis. In conclusion, the gross and microscopic characteristics of pituitary glands of the AGR are found to be similar to other rodents and mammals. We recommend further study to compare morphometrical parameters between male and females of this model.
Traumatic Brain Injury (TBI) represents a major public health burden and a major contributor to disability and death, especially in the young population. It remains one of the most challenging human conditions to classify and the non-standardized classification is one of the numerous barriers in proper diagnosis and effective translation of experimental treatments in animal models. TBI is associated with numerous disorders, including amnesia, Parkinson's Disease, sleep disorders, Alzheimer's Disease, as well as disruption of physical, cognitive, and mental functioning. Several health care providers and the insurance industry see TBI as a singular 'event', meaning that the brain ''repairs'' over time, and does not require additional therapies. However, a single mild TBI can induce problems that self-propagate for months or years after the injury. There currently exist no diagnostic methods to quantify the extent of emotional and behavioral changes, cognitive impairment, fatigue, and sleep issues resulting from TBI in affected individual. The various animal and injury models available for TBI research are limited in clinical trials because a single TBI event is not fully understood. This review highlights the classifications of TBI, its heterogeneity, neuropathological lesions, long term sequelae, association with neurodegenerative disorders in human and animal studies, and attempts to modify the notion of TBI being viewed as a singular event.STATEMENT OF SIGNIFICANCE: The significance and strength of this review article lies in its comprehensive exploration of Traumatic Brain Injury (TBI) by addressing various factors that contribute to its complexity. We carried out a careful and detailed review of TBI classifications with an aim to provide a clearer and more detailed understanding of the heterogeneity inherent in these injuries. The examination of neuropathological lesions associated with TBI offers critical insights into the intricate nature of brain damage, fostering a deeper comprehension of the diverse outcomes resulting from TBI.Furthermore, this review critically evaluates the long-term sequelae of TBI, shedding light on the often-overlooked extended consequences that impact individuals well beyond the initial injury period. The findings from human and animal studies not only enriches our understanding of TBI but also highlights the translational implications for both clinical and preclinical research.A pivotal aspect of our review involves investigating the association between TBI and neurodegenerative disorders. By combining information from human studies and animal models, we aim to contribute to the growing body of knowledge that elucidates the intricate links between TBI and the development of neurodegenerative conditions.Most notably, this review challenges the conventional notion of TBI as a singular event by incorporating perspectives that emphasize its multifaceted nature. We critically assess attempts to modify this prevailing paradigm, encouraging a more nuanced understanding that considers the diverse manifestations and outcomes associated with TBI.In essence, this review endeavours to serve as a valuable resource for researchers, clinicians, and policymakers, fostering a comprehensive understanding of TBI that transcends traditional classifications and contributes to a more holistic approach in both research and clinical practice.
Squirrels are diurnal rodents with high visual acuity including unique properties well-suited for their natural environment. This study was conducted to explore some ocular microscopic features of tree-harbouring squirrels in the University of Ibadan, Ibadan, Nigeria. Two male squirrels were cage-trapped within the University premises. Light microscopic analysis was carried on paraffin-embedded eye samples harvested from the animals. The densely compacted stromal fibres, 351 ± 52.5 µm thick, formed the thickest part of the cornea, and the basement membrane of the corneal epithelium, 63.8 ± 13.0 µm thick, was notably positive with Periodic Acid Schiff (PAS) stain. Strong pigmentation was present at the choroid as well as the iridal and ciliary epithelia. The multiple layering of the retinal structure exhibited densely packed ganglion cells at the ganglion cell layer which together with the nerve fibre layer was observed to be thinnest at the more peripheral portion but becomes thicker towards the optic disc. Strongly positive glia fibrillary acidic protein (GFAP+) cells with their abundant fibrous processes were demonstrated immunohistochemically at the retinal nerve fibre layer and the optic nerve. Histological features of the retinal cellular components of the tree squirrels investigated has thus highlighted the structural adaptation of these animal species to their environmental arboreal habitat and diurnal lifestyle. Findings from this study, while further noted to be similar to that in human, showed that African tree squirrels represent promising rodent model for human retinal/ocular research.
Environmental pollution due to heavy metal pollution is of growing concern, due to the increased industrial activities. The release of these substances into the atmosphere poses a great risk to humans, animals and the ecosystem at large. This study assesses the metal concentration levels of nine metals (lead, nickel, magnesium, cadmium, chromium, manganese, cobalt, copper and iron) in the sera and different brain regions (cerebellum, cerebrum and brainstem) of the hedgehog (Eulipotyphla), pigeon (Columbiformes), cattle egret (Pelecaniformes) and two species of the squirrel (sciuromorpha) using Atomic Absorption Spectrophotometry. Results obtained showed that of all the metals tested for, magnesium had the highest concentration across all samples and regions in all animals tested. Metal levels appeared to be higher than those reported in some previous studies from other climes, except for cobalt where there was no detectable level in all the tissues tested. Values obtained were highest in the serum, more than the brain. There was no particular pattern to the concentration of the metals in the brain regions. Data obtained from this study will serve as an indicator of the level of environmental pollution going on, and the long-term effect it can have on wildlife behavioural patterns and consequently the ecosystem.
Aging is accompanied with various forms of functional ultrastructural and morphological changes in the eye, including the retina, leading to vision deterioration. However, age related retinal degenerative changes requires further elucidation especially as all previous studies on age-related change of the retina were done in mutant mouse strain models of hereditary retinal degenerations. The potential of using African giant rats (AGRs) as models for ageing in the eye, especially retina, was explored in this study. A total of 14 AGRs divided into two age groups (juvenile and adult) were used to study the histomorphology and histomorphometrics of the retina as well as retinal astrocyte morphology and heterogeneity. Histological findings included retinal atrophy and hypoplasia, with cellular swellings of neuronal cell populations and astrocytes soma and ramifications in the retina of adult compared to juvenile AGR. We suggest that AGR be used as animal model for translational research into normal aging process of the retina, as well as to elucidate the process of age-related neuronal cells loss.
Vanadium is a prevalent neurotoxic transition metal with therapeutic potentials in some neurological conditions. Hydrocephalus poses a major clinical burden in neurological practice in Africa. Its primary treatment (shunting) has complications, including infection and blockage; alternative drug-based therapies are therefore necessary. This study investigates the function and cytoarchitecture of motor and cerebellar cortices in juvenile hydrocephalic mice following treatment with varying doses of vanadium. Fifty juvenile mice were allocated into five groups (n = 10 each): controls, hydrocephalus-only, low- (0.15 mg/kg), moderate- (0.3 mg/kg), and high- (3.0 mg/kg) dose vanadium groups. Hydrocephalus was induced by the intracisternal injection of kaolin and sodium metavanadate administered by intraperitoneal injection 72hourly for 28 days. Neurobehavioral tests: open field, hanging wire, and pole tests, were carried out to assess locomotion, muscular strength, and motor coordination, respectively. The cerebral motor and the cerebellar cortices were processed for cresyl violet staining and immunohistochemistry for neurons (NeuN) and astrocytes (glial fibrillary acidic protein). Hydrocephalic mice exhibited body weight loss and behavioral deficits. Horizontal and vertical movements and latency to fall from hanging wire were significantly reduced, while latency to turn and descend the pole were prolonged in hydrocephalic mice, suggesting impaired motor ability; this was improved in vanadium-treated mice. Increased neuronal count, pyknotic cells, neurodegeneration and reactive astrogliosis were observed in the hydrocephalic mice. These were mostly mitigated in the vanadium-treated mice, except in the high-dose group where astrogliosis persisted. These results demonstrate a neuroprotective potential of vanadium administration in hydrocephalus. The molecular basis of these effects needs further exploration. The neuroprotective potentials of varying doses of vanadium were studied in an experimental model of hydrocephalus. All doses improved motor function, restored neuronal and glial count, and architecture; however, the high dose resulted in persistent astrocytic reactivity.image
Concerns about inappropriate disposal of waste into unsanitary municipal solid waste landfills around the world have been on the increase, and this poses a public health challenge due to leachate production. The neurotoxic effect of Gwagwalada landfill leachate (GLL) was investigated in male adult Wistar rats. Rats were exposed to a 10% concentration of GLL for 21 days. The control group received tap water for the same period of the experiment. Our results showed that neurobehavior, absolute body and brain weights and brain histomorphology as well as parvalbumin interneurons were severely altered, with consequent astrogliosis and microgliosis after 21 days of administrating GLL. Specifically, there was severe loss and shrinkage of Purkinje cells, with their nucleus, and severe diffused vacuolations of the white matter tract of GLL-exposed rat brains. There was severe cell loss in the granular layer of the cerebellum resulting in a reduced thickness of the layer. Also, there was severe loss of dendritic arborization of the Purkinje cells in GLL-exposed rat brains, and damage as well as reduced populations of parvalbumin-containing fast-spiking GABAergic interneurons in various regions of the brain. In conclusion, data from the present study demonstrated the detrimental effects of Gwagwalada landfill leachate on the brain which may be implicated in neuropsychological conditions.
Abstract Vanadium (V), a heavy metal, has been reported to induce central nervous system toxicity leading to various behavioural impairments. It is characterized by the production of reactive oxygen. The present study was designed to test the possibility of Grewia carpinifolia ethanolic extract in preventing behavioural alterations following acute vanadium toxicity in mice. Twenty five Swiss albino mice (25—27 g) were completely randomized into 5 groups (A—E) of 5 animals each. Group A received distilled water and served as a control; group B, received vitamin E (500 mg.kg−1 b. w. every 72 hours), a known antioxidant orally, along with a daily dose of sodium metavanadate intraperitoneally (i. p.) for 7 days; group C and group D received Grewia carpinifolia leaf extract at 100 and 200 mg.kg−1 b.w orally respectively, along with the sodium metavanadate i. p. for 7 days; while group E received sodium metavanadate i. p. only for 7 days. The behavioural and motor functions were analysed by the open field, negative geotaxis, and hanging wire tests; the daily body and brain weights were recorded. Grewia carpinifolia ethanolic extracts significantly reduced the number of grooming, stretched attend posture, and freezing time that were significantly increased in the vanadium only group and also enhanced the vestibular functions. In addition, the latent time spent on the hanging wire in groups simultaneously administered with the extract and V compared favourably (P > 0.05) with the control groups but a decrease in latent time was observed in the V only group. The results suggest that acute V toxicity results in various behavioural deficits and support a possible role of Grewia carpinifolia as a protective agent against acute vanadium-toxicity with a better result at 200 mg.kg−1 b. w.
Vanadium is a widely used transition metal in industrial applications, but it also poses significant neurotoxic and environmental risks. Previous studies have shown that exposure to vanadium may lead to neurodegenerative diseases and neuropathic pain, raising concerns about its impact on human health and the ecosystem. To address vanadium neurotoxicity, through targeting NMDA glutamate and dopamine signaling, both involved in neurodegenerative disorders, shows promise. Using Caenorhabditis elegans as a model, we evaluated a novel compound with a mixed NMDA glutamate receptor-dopamine transporter pharmacology, ZA-II-05 and found it effectively ameliorated vanadium-induced neurotoxicity, suggesting a potential neuroprotective role. Synchronized young adult worms were assigned to four different experimental groups; Controls; 100 mM of Vanadium; Vanadium and 1 mg/ml ZA-II-05; and ZA-II-05 alone. These were examined with different markers, including DAPI, MitoTracker Green and MitoSox stains for assessment of nuclei and mitochondrial density and oxidative stress, respectively. Exposure to vanadium in C. elegans resulted in decreased nuclear presence and reduction in mitochondrial content were also analyzed based on fluorescence in the pharyngeal region, signifying an increase in the production of reactive oxygen species, while vanadium co-treatment with ZA-II-05 caused a significant increase in nuclear presence and mitochondrial content. Treatment with ZA-II-05 significantly preserved cellular integrity, exhibiting a reversal of the detrimental effects induced by vanadium by modulating and preserving the normal function of chemosensory neurons and downstream signaling pathways. This study provides valuable insights into the mechanisms of vanadium-induced neurotoxicity and offers perspectives for developing therapeutic interventions for neurodegenerative diseases related to environmental toxins.
Crimean-Congo haemorrhagic fever orthonairovirus (CCHFV) and Dugbe orthonairovirus (DUGV) are zoonotic viruses transmitted by ticks. Whereas CCHFV has caused numerous human cases, DUGV, although less reported, shares ticks and ruminants as hosts. Since its first discovery in Nigeria in 1964, there has been no detailed sero-epidemiological investigation on DUGV in sub-Saharan Africa. This study is aimed at assessing the current seroprevalence and associated risk factors of CCHFV and DUGV infections in Nigerian cattle. Using a cross-sectional design with random sampling method, blood samples were collected from 877 cattle on pastoralist farms and at abattoirs in Kwara State, North-Central Nigeria. CCHFV IgG antibodies were detected in extracted sera using three panels of in-house indirect enzyme-linked immunosorbent assay (ELISA) based on bacteria-expressed recombinant nucleoprotein (rNP), the cattle-adapted VectoCrimean ELISA and the ID Screen CCHF double antigen multi-species ELISA, while DUGV IgG antibodies were detected using in-house indirect ELISA with bacteria-expressed rNP, indirect immunofluorescence assay and micro-Virus Neutralization test. Overall seroprevalence rates of 71.9% (631/877) and 52.8% (451/854) were obtained for CCHFV and DUGV, respectively. It was observed that 37.9% (314/829) of the cattle were co-exposed to both CCHFV and DUGV while 34.5% (286/829), 14.8% (123/829) and 12.8% (106/829) were exposed to single infections with CCHFV, DUGV or none of the two viruses, respectively. Multivariate analysis showed that only location, sex, age and tick infestation score were the risk factors that significantly affected CCHFV seroprevalence in cattle, while DUGV seroprevalence was significantly influenced by month of the year, location, cattle breed and sex (p<0.05). This is the first comprehensive sero-epidemiological surveillance for DUGV in sub-Saharan Africa. Our findings reveal widely distributed independent CCHFV and DUGV infections in cattle in Kwara State, Nigeria.
Introduction: Alterations of antioxidant defense, neuroinflammation, and neurodegeneration are common pathological occurrences associated with neurodegenerative diseases. This study evaluated the neuroprotective effect of Launaea taraxacifolia (LT), popularly known as African Wild lettuce, against neuroinflammation, memory loss, and neurobehavioral deficit. Methods: Adult Wistar rats were used following random assignment into groups 1 to 5. Group one was the normal control. Groups four to five received 40 mg/kg Nω-nitro-l-arginine methyl ester (L-NAME). In addition to L-NAME exposure, groups three and four received 100 and 200 mg/kg LT, whereas group five received 10 mg/kg lisinopril. The experiment lasted for five weeks. Markers of oxidative stress, neurobehavioural studies, histology, and immunohistochemistry of glial fibrillary acidic protein (GFAP), ionised calcium-binding adaptor molecule 1 (Iba-1), as well as anti-calbindin for staining astrocytes, microglia, and Purkinje cells were determined. Results: Malondialdehyde (MDA) and protein carbonyl in the L-NAME alone group were heightened compared to those treated with LT. However, treatment with LT significantly reduced neuronal oxidative stress, neuroinflammation, and neurobehavioural changes. Quantitative analysis of immunohistochemical staining revealed heightened glial fibrillary acidic protein (GFAP), ionised calcium-binding adaptor molecule 1 (Iba-1), as well as anti-calbindin as indicated by astrogliosis, microgliosis, and Purkinje cell degeneration in untreated rats. Moreover, the observed ultrastructural anarchy induced by L-NAME was restored in rats treated with LT (P<0.05). Conclusion: Together, the leaf extract of LT can be effective as a neuroprotective drug candidate.