Social behaviors in the African wild dog (Lycaon pictus) commonly involve a range of tactile aspects, including biting, pushing, embracing, mounting, face and muzzle licking, nose-chin and muzzle contact, paw placement, play fighting, and wrestling, supported by the vestibular system. We employed an array of architectural and immunohistochemical stains to provide a qualitative description of the somatosensory and vestibular systems in the brain of one representative African wild dog individual. The appearance of both systems does not appear to differ from that reported in other Carnivora. The six nuclei forming the vestibular system, and their relationship to each other and the incoming vestibular branch of the eighth cranial nerve, appear like those observed in many mammalian species. The location and appearance of the dorsal column nuclei, the trigeminal sensory column, the colliculi, somatosensory nuclei of the dorsal thalamus, and the five somatosensory cortical areas observed in the African wild dog are like those observed in the domestic dog and other Carnivora. This study of the somatosensory and vestibular systems of the African wild dog completes our series of studies describing the major sensory systems in the African wild dog brain. It appears reasonable to conclude that, at the systems level of analysis, no overt specializations of any of the sensory systems are present. Thus, the neural underpinnings of the complex sociality of the African wild dog may be supported by nonsensory neural systems, such as motor, neuromodulatory, limbic, or cognitive systems, or levels of organization like receptor expression patterns or connectivity.
Social behaviors in the African wild dog involve a range of complex movements, including biting, pushing, embracing, mounting, face and muzzle licking, paw placement, play fighting, and wrestling. In this study, we employ a range of architectural and immunohistochemical stains to provide a qualitative description of the motor system in the brain of one representative individual of the African wild dog. The appearance of the motor system in the African wild dog does not differ substantively to that reported in other carnivores and is neurochemically like that of the domestic dog; however, one significant difference was detected: the presence of a distinct fascicle of protoplasmic commissural dendrites at the rostral pole of the hypoglossal nucleus. The chemoarchitecture and complement of motor cortical areas and dorsal thalamus, striatopallidal complex and associated nuclei, cerebellum, red nucleus, descending motor pathways, inferior olivary nuclear complex, cranial nerve motor nuclei, and ventral horn of the cervical spinal cord of the African wild dog do not reveal qualitative differences to that observed in the domestic dog. At the rostral pole of the hypoglossal nucleus, protoplasmic commissural dendrites form a distinct fascicle, this fascicle being a feature that has not been reported in other mammals. The presence of this feature indicates complex neural control of the tongue and may facilitate vocalization control through the potential combination of lateralized aspects of vocalizations in a nucleus playing a major role in the production of vocalizations.
Background: Benzodiazepines (BZDs) are a class of depressant drugs that have enjoyed widespread use in conventional clinical management of anxiety-related conditions such as panic disorders that require therapeutic central relaxation and sedation. Meanwhile, prolonged administration of benzodiazepines even at low doses has however been linked to variety of undesirable effects such as discontinuation relapse with the associated risk of abuse and dependency. Aim: This study investigated the behavioral, histological and biochemical outcomes of long-term low dose diazepam use and explored the potential role of nigella sativa oil (NSO) in the amelioration of the associated side effects. Methods: Adult Wistar rats (n=32) were randomized into four groups that received normal saline; diazepam; diazepam + NSO; or NSO only, respectively for 14 days. At the end of the period of the various exposures, the rats were taken through behavioral paradigms after which they were sacrificed for chemical and histological profiling. Results: diazepam-exposed rats exhibited stress-related manifestations with relatively poor performance in memory-related tasks. Repeated diazepam ingestion reduced brain antioxidant biomarkers while causing elevation of brain oxidative stress markers. On histological observation, mild degenerative changes were evident in the various brain regions of the diazepam-exposed rats. Conclusion: Interventional nigella sativa oil administration showed therapeutic potentials by mitigating and reversing the observed effects of diazepam, largely due to its antioxidant and anti-inflammatory effects as observed in the present study.
Voluntary donation is the ethically acceptable method for whole-body acquisition for anatomy education worldwide. In Africa, educational institutions struggle with this since many people remain unwilling to donate their bodies due to the strong influence of cultural and religious beliefs in decision-making. As part of wider efforts to improve the ethical sourcing of bodies in Zimbabwean medical schools, which are heavily reliant on unclaimed bodies, this study sought to determine the influences traditional and religious beliefs have on such decisions. We ascertained traditional and religious leaders' knowledge of whole-body donation, explored cultural and religious views toward death, dying and whole-body donation as well as their underlying reasons. Semi-structured interviews were conducted with traditional chiefs and Christian leaders who are considered the custodians of Zimbabwean traditional cultural and Christian values, respectively. Thematic analysis of traditional chiefs' interviews revealed that none of the chiefs had accurate knowledge regarding whole-body donation or the processes involved. Due to set traditional practices around death, most traditional chiefs viewed the practice as foreign with possible negative repercussions to the dissectors. Most of the Christian leaders had knowledge of whole-body donation. Their views were split between support for whole-body donation and regard as a religious and cultural misfit. Overall, both traditional chiefs and Christian leaders understood the importance of whole-body donation and requested further societal sensitization and education if the practice is to become socially acceptable.
Anatomy is a challenging preclinical subject owing to the vast amount of information that students need to master. The adoption of relevant study approaches is key to the development of a long-lasting understanding of anatomical subject matter. Phenomenographic educational research describes the medical students as using a variable mix of deep, strategic, and surface approaches to study. Continually assessing students' learning preferences and approaches is crucial for achieving the desired learning outcomes. The approaches to studying anatomy in two groups of first-year Zimbabwean medical students from two newly established medical schools were collected using the Approaches and Study Skills Inventory for Students (ASSIST) instrument and than analyzed. At least 90% of the students believed that anatomy involved reproducing knowledge or personal understanding and development. Overall, the majority of the students adopted deep and strategic approaches, while a distant minority used the surface approach. There was no significant correlation between either the students' sex or age and their preference for a specific approach to studying. The mean anatomy grades for students using a strategic approach were significantly higher than those using deep or surface approaches. The number of strategic learners was double that of deep learners among the high achievers subgroup. The strategic approach positively correlated with performance in examinations. Generally, the students shared a common understanding of the concept of anatomy learning. Studies such as this can assist with the identification of students at risk of failure and empower lecturers to recommend the adoption of more beneficial strategic and deep learner traits.
Employing a range of neuroanatomical stains, we detail the organization of the main and accessory olfactory systems of the African wild dog. The organization of both these systems follows that typically observed in mammals, but variations of interest were noted. Within the main olfactory bulb, the size of the glomeruli, at approximately 350 mu m in diameter, are on the larger end of the range observed across mammals. In addition, we estimate that approximately 3,500 glomeruli are present in each main olfactory bulb. This larger main olfactory bulb glomerular size and number of glomeruli indicates that enhanced peripheral processing of a broad range of odorants is occurring in the main olfactory bulb of the African wild dog. Within the accessory olfactory bulb, the glomeruli did not appear distinct, rather forming a homogenous syncytia-like arrangement as seen in the domestic dog. In addition, the laminar organization of the deeper layers of the accessory olfactory bulb was indistinct, perhaps as a consequence of the altered architecture of the glomeruli. This arrangement of glomeruli indicates that rather than parcellating the processing of semiochemicals peripherally, these odorants may be processed in a more nuanced and combinatorial manner in the periphery, allowing for more rapid and precise behavioral responses as required in the highly social group structure observed in the African wild dog. While having a similar organization to that of other mammals, the olfactory system of the African wild dog has certain features that appear to correlate to their environmental niche.
The large external pinnae and extensive vocal repertoire of the African wild dog (Lycaon pictus) has led to the assumption that the auditory system of this unique canid may be specialized. Here, using cytoarchitecture, myeloarchitecture, and a range of immunohistochemical stains, we describe the systems-level anatomy of the auditory system of the African wild dog. We observed the cochlear nuclear complex, superior olivary nuclear complex, lateral lemniscus, inferior colliculus, medial geniculate body, and auditory cortex all being in their expected locations, and exhibiting the standard subdivisions of this system. While located in the ectosylvian gyri, the auditory cortex includes several areas, resembling the parcellation observed in cats and ferrets, although not all of the auditory areas known from these species could be identified in the African wild dog. These observations suggest that, broadly speaking, the systems-level anatomy of the auditory system, and by extension the processing of auditory information, within the brain of the African wild dog closely resembles that observed in other carnivores. Our findings indicate that it is likely that the extraction of the semantic content of the vocalizations of African wild dogs, and the behaviors generated, occurs beyond the classically defined auditory system, in limbic or association neocortical regions involved in cognitive functions. Thus, to obtain a deeper understanding of how auditory stimuli are processed, and how communication is achieved, in the African wild dog compared to other canids, cortical regions beyond the primary sensory areas will need to be examined in detail.
The African wild dog is endemic to sub-Saharan Africa and belongs to the family Canidae which includes domestic dogs and their closest relatives (i.e., wolves, coyotes, jackals, dingoes, and foxes). The African wild dog is known for its highly social behavior, co-ordinated pack predation, and striking vocal repertoire, but little is known about its brain and whether it differs in any significant way from that of other canids. We employed gross anatomical observation, magnetic resonance imaging, and classical neuroanatomical staining to provide a broad overview of the structure of the African wild dog brain. Our results reveal a mean brain mass of 154.08 g, with an encephalization quotient of 1.73, indicating that the African wild dog has a relatively large brain size. Analysis of the various structures that comprise their brains and their topological inter-relationships, as well as the areas and volumes of the corpus callosum, ventricular system, hippocampus, amygdala, cerebellum and the gyrification index, all reveal that the African wild dog brain is, in general, similar to that of other mammals, and very similar to that of other carnivorans. While at this level of analysis we do not find any striking specializations within the brain of the African wild dog, apart from a relatively large brain size, the observations made indicate that more detailed analyses of specific neural systems, particularly those involved in sensorimotor processing, sociality or cognition, may reveal features that are either unique to this species or shared among the Canidae to the exclusion of other Carnivora.
Over the last 15 years, research on canid cognition has revealed that domestic dogs possess a surprising array of complex sociocognitive skills pointing to the possibility that the domestication process might have uniquely altered their brains; however, we know very little about how evolutionary processes (natural or artificial) might have modified underlying neural structure to support species‐specific behaviors. Evaluating the degree of cortical folding (i.e., gyrification) within canids may prove useful, as this parameter is linked to functional variation of the cerebral cortex. Using quantitative magnetic resonance imaging to investigate the impact of domestication on the canine cortical surface, we compared the gyrification index (GI) in 19 carnivore species, including six wild canid and 13 domestic dog individuals. We also explored correlations between global and local GI with brain mass, cortical thickness, white and gray matter volume and surface area. Our results indicated that GI values for domestic dogs are largely consistent with what would be expected for a canid of their given brain mass, although more variable than that observed in wild canids. We also found that GI in canids is positively correlated with cortical surface area, cortical thickness and total cortical gray matter volumes. While we found no evidence of global differences in GI between domestic and wild canids, certain regional differences in gyrification were observed.
The variegated pelage and social complexity of the African wild dog (Lycaon pictus) hint at the possibility of specializations of the visual system. Here, using a range of architectural and immunohistochemical stains, we describe the systems-level organization of the image-forming, nonimage forming, oculomotor, and accessory optic, vision-associated systems in the brain of one representative individual of the African wild dog. For all of these systems, the organization, in terms of location, parcellation and topology (internal and external), is very similar to that reported in other carnivores. The image-forming visual system consists of the superior colliculus, visual dorsal thalamus (dorsal lateral geniculate nucleus, pulvinar and lateral posterior nucleus) and visual cortex (occipital, parietal, suprasylvian, temporal and splenial visual regions). The nonimage forming visual system comprises the suprachiasmatic nucleus, ventral lateral geniculate nucleus, pretectal nuclear complex and the Edinger-Westphal nucleus. The oculomotor system incorporates the oculomotor, trochlear and abducens cranial nerve nuclei as well as the parabigeminal nucleus, while the accessory optic system includes the dorsal, lateral and medial terminal nuclei. The extent of similarity to other carnivores in the systems-level organization of these systems indicates that the manner in which these systems process visual information is likely to be consistent with that found, for example, in the well-studied domestic cat. It would appear that the sociality of the African wild dog is dependent upon the processing of information extracted from the visual system in the higher-order cognitive and affective neural systems.
Oxidative damages in organophosphates poisoning is associated with neuro-cognitive deficits. This study investigates the protective effect of Nigella sativa oil (NSO) in mitigating dichlorvos (DDVP) induced oxidative damage and neuro-cognitive impairment in rats. Thirty-two rats were randomly divided into four groups, exposed to 1 ml/kg of normal saline, 8.8 mg/kg of DDVP, DDVP + 1 ml/kg of NSO and NSO respectively for 14 consecutive days. Body weights were recorded at day 1 and 15 of the experiment, the rats were exposed to 3 trials each on the 11, 12 and 13th days in the Morris water maze, and subsequently latency to hidden platform and time in the platform quadrant were recorded as measures of long term memory (LTM), short term memory (STM) and reference memory on the 14th day. The rats were euthanized on the 15th day, the brains excised and the hippocampi of five brains in each group were removed, homogenized to analyze for total reactive oxygen species (ROS), nitrous oxide (NO) levels and acetylcholinesterase (AChE) activities, while the other three were processed for histology and Ki67 immunohistochemistry. DDVP exposure caused a significant increase in hippocampal NO and ROS levels, with reductions in AChE activities and Ki67 protein expression. This was associated with delayed escape latency and reduced time in platform quadrant. NSO intervention prevented outburst in ROS and NO, preserved the neurogenic cells and improved neuro-cognitive indices. We thus conclude that stabilizing oxidative and neurogenic functions are vital to protect against DDVP hippocampal insults.
Chlopyrifos (CPF) is an organophosphate, implicated in brain damage and cognitive deficits, whose consistence deposit in the environment has contributed to the toxicity burdens of xenobiotics. This study investigated the efficacy of Nigella sativa oil (NSO) against CPF insults on the hippocampus. Thirty-two rats were randomly divided into four groups of eight rats each, exposed to 1 ml/kg of Normal saline, 14.9 mg/kg of CPF, 14.9 mg/kg of CPF plus 1 ml/kg of NSO and 1 ml/kg of NSO respectively for 14 consecutive days. The rats were exposed to 3 trials each on the 11-13 days in the Morris water maze, and subsequently latency to hidden platform and time in the platform quadrant were recorded as measures of long term memory (LTM), short term memory (STM) and reference memory (RM) on the 14th day. The rats were euthanized on day 15, the brains excised, and the hippocampus of five brains removed, homogenized to analyze for total reactive oxygen species (ROS), nitric oxide (NO) levels and acetylcholinesterase (AChE) activities, while the other three were processed for histology and Ki67 immunohistochemistry. CPF caused a marked increase in hippocampal NO and ROS activities, depleted AChE activities and Ki67 expressions, delayed escape latency and reduced visit to the platform quadrant. Intervention with NSO depleted ROS/NO levels, improved neurogenic proteins, AChE activities and neuro-cognitive markers depletions in CPF exposure. Altogether, our findings showed that NSO is a potential therapeutic drug for the treatment of CPF-induced cognitive deficit through its antioxidant property and adult neurogenesis in rats. (C) 2018 The Authors. Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative.
The execution of agricultural activities on an industrial scale has led to indiscriminate deposition of toxic xenobiotics, including organophosphates, in the biome. This has led to intoxication characterized by deleterious oxidative and neuronal changes. This study investigated the consequences of oxidative and neurogenic disruptions that follow exposure to a combination of two organophosphates, chlorpyrifos (CPF) and dichlorvos (DDVP), on neuro-cognitive performance and anxiety-like behaviors in rats. Thirty-two adult male Wistar rats (150⁻170 g) were randomly divided into four groups, orally exposed to normal saline (NS), DDVP (8.8 mg/kg), CPF (14.9 mg/kg), and DDVP + CPF for 14 consecutive days. On day 10 of exposure, anxiety-like behavior and amygdala-dependent fear learning were assessed using open field and elevated plus maze paradigms, respectively, while spatial working memory was assessed on day 14 in the Morris water maze paradigm, following three training trials on days 11, 12, and 13. On day 15, the rats were euthanized, and their brains excised, with the hippocampus and amygdala removed. Five of these samples were homogenized and centrifuged to analyze nitric oxide (NO) metabolites, total reactive oxygen species (ROS), and acetylcholinesterase (AChE) activity, and the other three were processed for histology (cresyl violet stain) and proliferative markers (Ki67 immunohistochemistry). Marked (p ≤0.05) loss in body weight, AChE depletion, and overproduction of both NO and ROS were observed after repeated exposure to individual and combined doses of CPF and DDVP. Insults from DDVP exposure appeared more severe owing to the observed greater losses in the body weights of exposed rats. There was also a significant (p ≤0.05) effect on the cognitive behaviors recorded from the exposed rats, and these deficits were related to the oxidative damage and neurogenic cell loss in the hippocampus and the amygdala of the exposed rats. Taken together, these results provided an insight that oxidative and neurogenic damage are central to the severity of neuro-cognitive dysfunction and increased anxiety-like behaviors that follow organophosphate poisoning.
Use of highly active antiretroviral therapy has led to marked reductions in the incidence of HIV-associated opportunistic infections but has had comparatively less impact on the incidence of some pulmonary diseases. This study was done to determine the pulmonary conditions leading to hospital admissions in people living with HIV/AIDS at two central hospitals in Zimbabwe and the pulmonary rehabilitation intervention received.
BackgroundWhile burns take seconds to occur, the resulting injuries result in pain and undesirable long-term (often lifelong) effects. The study was carried out to determine the practices, beliefs, and sources of information related to burns and first aid among caregivers of children who present to hospital with burn injuries in Harare, Zimbabwe.MethodsA cross-sectional study was carried out over a period of 3 months at 2 central hospitals in Harare (Parirenyatwa Group of Hospitals and Harare Central Hospital). A questionnaire was administered to the caregivers of children, aged 0 to 60 months and admitted to the burns wards, to elicit information on the circumstances of the burn injury and the first aid methods which were administered.ResultsOut of the 50 children who were recruited, 54.0% were females and the mean age was 29.5 months (SD = 15.5). As first aid for the burn injuries that brought these children to hospital, 30 (60.0%) of the caregivers cooled the burn with cold running water. Some caregivers applied eggs, margarine, or traditional herbs as first aid. Other first aid practices reported by the caregivers included the use of urine and crushed cockroaches (n = 40; 80.0%), while 20 caregivers (40.0%) used aloe vera gel. About half of the caregivers received first aid information mainly from family members and very few indicated that the information was obtained from mass media (n = 3; 6.0%).ConclusionsThe first aid measures used by the majority of caregivers were either incomplete or inadequate. Although some caregivers had adequate knowledge of what to do after an injury, there still was widespread use of alternative therapies in burn management.