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Among the various systems taught in the preclinical phases, the nervous system is more challenging to learn than other systems. In this report, a novel teaching methodology, "real-life scenario (RLS) blended teaching," is described and its effectiveness in facilitating inquisitive learning in undergraduate medical students is evaluated. This mixed-method study was conducted among three groups (group 1, n = 83; group 2, n = 85; and group 3; n = 79) of undergraduate medical students (18-20 yr) in the neurology and behavioral sciences module. RLS was presented to students in the form of demonstrations, role-plays, videos, and group activities. Group 1 students underwent traditional teaching-learning sessions. Group 2 students underwent RLS blended sessions and were provided with multiple miniassignments in a vignette format. Group 3 students received RLS blended sessions, multiple miniassignments, peer discussions, multiple formative assessments, and facilitator feedback sessions. The student performances on different exams were compared in terms of their group, and their perceptions of RLS were documented. Students exposed to RLS sessions blended with multiple assignments, peer discussions, multiple formative assignments, and facilitator feedback sessions performed well in the final summative assessments (67.87%) compared with those exposed to RLS sessions and assignments (50.21%) or exposed to traditional teaching alone (50.34%). RLS sessions increased students' curiosity and motivated them to learn the subject well. RLS sessions stimulated student interest and facilitated their learning. RLS along with effective use of multiple assignments, formative assessments, and/or feedback sessions significantly improved student learning. This demonstrates the effectiveness of this active method in teaching various subjects with appropriate modifications.NEW & NOTEWORTHY In this report, a novel teaching methodology, "real-life scenario (RLS) blended teaching" is described and its effectiveness in facilitating inquisitive learning in undergraduate medical students is evaluated. Students exposed to RLS sessions blended with multiple miniassignments, peer discussions, multiple formative assignments, and facilitator feedback sessions performed well in the summative assessments compared with those exposed to RLS sessions and assignments or exposed to traditional teaching alone. Students preferred active teaching-learning techniques over the traditional method.
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Estudiantes de Medicina , Humanos , Aprendizaje , Aprendizaje Basado en Problemas , Retroalimentación , Sistema Nervioso Central , EnseñanzaRESUMEN
Emerging viral infections are a ceaseless challenge and remain a global public health concern. The world has not yet come back to normal from the devastating effects of the highly contagious and pathogenic novel coronavirus, or Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Olfactory and taste dysfunction is common in patients infected by the novel coronavirus. In light of the emergence of different coronavirus variants, it is important to update the prevalence and pathophysiology of these side effects. In this review, articles published on the prevalence of olfactory and taste dysfunction from coronavirus disease (COVID-19) and their possible pathophysiologic mechanisms have been reviewed and reported. The modulatory role of different SARS-CoV-2 variants on the chemical senses is then described. The clinical relevance of chemical sense disorder and its long-term morbidity and management is also discussed.
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COVID-19 , SARS-CoV-2 , COVID-19/epidemiología , Humanos , Prevalencia , Trastornos del GustoRESUMEN
Conventional camera lucida (CL) aided neuronal tracing technique for studying neural plasticity is a demanding procedure. Stereo Investigator-Neurolucida enabled neuronal tracing system is not accessible to all researchers. This necessitates alternate simple and less challenging digitised neuronal tracing methods. This report describes a novel digitised neuronal tracing method using widefield microscopy, and its effectiveness is compared with the traditional camera lucida aided neuronal tracing method. Golgi-Cox stained hippocampal cornu ammonis area-3 (CA3) pyramidal neuron photomicrographs were serially captured at a depth of every 2µm in the z-axis by a wide field microscope from the point of appearance to the disappearance. These images were stacked along the axis perpendicular to the image plane to reconstruct the neuron in its entirety, digitally traced and dendritic quantification was performed using open source software. The same neurons were manually traced using camera lucida, and Sholl analysis was done manually to quantify the dendritic arborisation pattern. The dendritic quantification data were not significantly different in both methods. Hence, the technology-enabled, less demanding, and equally accurate neuronal tracing can be adopted instead of manual tracing and analysis of neurons. â¢A simple digitised neuronal tracing method is described.â¢It is fast, rigorous, and comparable to traditional tracing techniques.â¢Helps the researcher to repeatedly probe data to reduce errors.
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Epigenetic mechanisms, which include DNA methylation, a variety of post-translational modifications of histone proteins (acetylation, phosphorylation, methylation, ubiquitination, sumoylation, serotonylation, dopaminylation), chromatin remodeling enzymes, and long non-coding RNAs, are robust regulators of activity-dependent changes in gene transcription. In the brain, many of these epigenetic modifications have been widely implicated in synaptic plasticity and memory formation. Dysregulation of epigenetic mechanisms has been reported in the aged brain and is associated with or contributes to memory decline across the lifespan. Furthermore, alterations in the epigenome have been reported in neurodegenerative disorders, including Alzheimer's disease. Here, we review the diverse types of epigenetic modifications and their role in activity- and learning-dependent synaptic plasticity. We then discuss how these mechanisms become dysregulated across the lifespan and contribute to memory loss with age and in Alzheimer's disease. Collectively, the evidence reviewed here strongly supports a role for diverse epigenetic mechanisms in memory formation, aging, and neurodegeneration in the brain.
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Envejecimiento , Enfermedad de Alzheimer , Encéfalo , Ensamble y Desensamble de Cromatina , Disfunción Cognitiva , Epigénesis Genética , Trastornos de la Memoria , Acetilación , Envejecimiento/genética , Envejecimiento/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Animales , Encéfalo/metabolismo , Encéfalo/fisiopatología , Disfunción Cognitiva/genética , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/fisiopatología , Metilación de ADN/genética , Humanos , Trastornos de la Memoria/genética , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/fisiopatología , Plasticidad Neuronal/genética , Procesamiento Proteico-Postraduccional/genéticaRESUMEN
Although traditional didactic lecturing is the principal instructional approach used in numerous medical schools, this method has several limitations. Experiential learning approaches place students in the center of the learning process and creates a positive and supportive classroom learning environment. In this article, we propose an active pedagogical approach for teaching a basic physiology concept, namely, neuromuscular transmission (NMT), and we evaluate the effectiveness of this approach among undergraduate medical students. One-hundred forty-two undergraduate medical students were involved in this study (cohort A, n = 62; cohort B, n = 80). Cohort A received a didactic lecture on NMT and subsequently tested their knowledge of the topic via test 1, after which their perceptions of didactic lectures were recorded. The students were then asked to participate in a touch-and-go (TAG) active-learning session regarding NMT, after which their learning was subsequently tested by taking test 2. Their perceptions about the TAG game were also recorded. Students in cohort B were first administered test 1 regarding NMT. Then, they were asked to attend a didactic lecture blended with a TAG active-learning session, after which test 2 was administered, and their perceptions were recorded. Both the didactic lecture and active learning sessions facilitated student learning regarding the concepts involved in NMT. A comparison of the lecture followed by the game used in cohort A with the game blended lecture used in cohort B revealed no significant differences. However, both formats created a positive influence on students' interest in learning the concept, and the students preferred active learning over didactic sessions alone.
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Estudiantes de Medicina , Estudios de Cohortes , Humanos , Aprendizaje Basado en Problemas , Facultades de Medicina , EnseñanzaRESUMEN
BACKGROUND: The Stroop Colour and Word Test (SCWT) is the most extensively used neuropsychological test in humans to evaluate the ability to inhibit cognitive interference. Any music played while the listener's primary attention is focused on another activity is known as background music and its effects on SCWT have not been studied well. OBJECTIVE: The current study was designed to evaluate the influence of different background music (classical and heavy metal) on inhibiting cognitive interference in young adults by using the Stroop Colour and Word Test. METHODS: Eighty student volunteers were invited for the study after obtaining their informed consent. They were first tested for colour blindness using Ishihara's colour test, and once passed, they were recruited to perform a computerised Stroop colour-word interference test. Each participant was requested to take part in four reading exercises: monochrome words, rectangle colours, coloured words and colour naming, respectively. These exercises were performed under three different conditions such as silence (absence of background music), presence of heavy metal and classical music, respectively. The participants' reaction time, errors made and heart rate were recorded and compared. RESULTS: The participants' reaction time was found to be significantly decreased with classical and heavy metal background music compared with the silence condition. The heart rate and errors made by the participants did not significantly change during any of the study conditions. CONCLUSIONS: Results of this study indicate the positive impact of background music on a cognitive interference task. Further studies are warranted to elucidate the underlying neural mechanisms.
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Cognición/fisiología , Musicoterapia/métodos , Música/psicología , Adolescente , Adulto , Femenino , Humanos , Masculino , Ensayos Clínicos Controlados no Aleatorios como Asunto , Voluntarios , Adulto JovenRESUMEN
Golgi staining allows for the analysis of neuronal arborisations and connections and is considered a powerful tool in basic and clinical neuroscience. The fundamental rules for improving neuronal staining using the Golgi-Cox method are not fully understood; both intrinsic and extrinsic factors may control the staining process. Therefore, various conditions were tested to improve the Golgi-Cox protocol for vibratome-cut rat brain sections. Optimal staining of cortical neurons was achieved after 72 h of impregnation. Well-stained neurons in both cortical and subcortical structures were observed after 96 h of impregnation. The dendritic arborisation pattern of cortical neurons derived from the 72-h impregnation group was comparable to those of the 96 and 168-h impregnation groups. The entire brain was stained well when the pH of the Golgi-Cox solution was 6.5 and that of the sodium carbonate solution was 11.2. Lack of brain perfusion or perfusion with 0.9% NaCl did not influence optimal neuronal staining. Perfusion with 37% formaldehyde, followed by impregnation, only resulted in glial staining, but perfusion with 4% formaldehyde facilitated both glial and neuronal staining. Whole brains required longer impregnation times for better staining. Although every factor had a role in determining optimal neuronal staining, impregnation time and the pH of staining solutions were key factors among them. This modified Golgi-Cox protocol provides a simple and economical procedure to stain both neurons and glia separately.
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Aparato de Golgi/química , Neuroglía/química , Neuronas/química , Coloración y Etiquetado , Animales , Masculino , Neuroglía/citología , Neuronas/citología , Ratas , Ratas Wistar , Fijación del TejidoRESUMEN
The primary objective of mobile phone technology is to achieve communication with any person at any place and time. In the modern era, it is impossible to ignore the usefulness of mobile phone technology in cases of emergency as many lives have been saved. However, the biological effects they may have on humans and other animals have been largely ignored and not been evaluated comprehensively. One of the reasons for this is the speedy uncontrollable growth of this technology which has surpassed our researching ability. Initiated with the first generation, the mobile telephony currently reaches to its fifth generation without being screened extensively for any biological effects that they may have on humans or on other animals. Mounting evidences suggest possible non-thermal biological effects of radiofrequency electromagnetic radiation (RF-EMR) on brain and behavior. Behavioral studies have particularly concentrated on the effects of RF-EMR on learning, memory, anxiety, and locomotion. The literature analysis on behavioral effects of RF-EMR demonstrates complex picture with conflicting observations. Nonetheless, numerous reports suggest a possible behavioral effect of RF-EMR. The scientific findings about this issue are presented in the current review. The possible neural and molecular mechanisms for the behavioral effects have been proposed in the light of available evidences from the literature.
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Ansiedad/etiología , Encéfalo/efectos de la radiación , Teléfono Celular , Campos Electromagnéticos/efectos adversos , Memoria/efectos de la radiación , Ondas de Radio , Animales , Barrera Hematoencefálica/efectos de la radiación , Encéfalo/fisiopatología , Radiación Electromagnética , Humanos , Aprendizaje/efectos de la radiación , Locomoción/efectos de la radiaciónRESUMEN
In the behavioral science field, many of the oldest tests have still most frequently been used almost in the same way for decades. The subjective influence of human observer and the large inter-observer and interlab differences are substantial among these tests. This necessitates the possibility of using technological innovations for behavioral science to obtain new parameters, results and insights as well. The light-dark box (LDB) test is a characteristic tool used to assess anxiety in rodents. A complete behavioral analysis (including both anxiety and locomotion parameters) is not possible by performing traditional LDB test protocol, as it lacks the usage of a real-time video recording of the test. In the current report, we describe an improved approach to conduct LDB test using a real-time video tracking system.
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Ansiedad/psicología , Conducta Animal , Oscuridad , Luz , Locomoción , Actividad Motora , Fotoperiodo , Grabación en Video/métodos , Animales , Ansiedad/fisiopatología , Modelos Animales de Enfermedad , Masculino , Aprendizaje por Laberinto , Ratas Wistar , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
The purpose of the study was to evaluate the changes in amygdala morphology and emotional behaviors, upon exposure to chronic RF-EMR in adolescent rats. Four weeks old male albino Wistar rats were exposed to 900â¯MHz (power density:146.60⯵W/cm2) from a mobile phone in silent-mode for 28 days. Amygdala morphology was studied using cresyl violet, TUNEL and Golgi-Cox staining. Place preference behavior was studied using light/dark chamber test and following this brain caspase-3 activity was determined. Number of healthy neurons was decreased in the basolateral amygdala and cortical amygdala but not in the central amygdala after RF-EMR exposure. It also induced apoptosis in the amygdala. RF-EMR exposure altered dendritic arborization pattern in basolateral amygdala but not in the central amygdala. Altered place preference and hyperactivity-like behavior was evident after RF-EMR exposure, but brain caspase-3 activity did not change. RF-EMR exposure perturbed normal cellular architecture of amygdala and this was associated with altered place preference.
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Encéfalo/efectos de la radiación , Caspasa 3/metabolismo , Radiación Electromagnética , Animales , Apoptosis/efectos de la radiación , Conducta Animal/efectos de la radiación , Encéfalo/metabolismo , Encéfalo/patología , Condicionamiento Operante/efectos de la radiación , Masculino , Neuronas/patología , Neuronas/efectos de la radiación , Ratas WistarRESUMEN
The present study reports perceptions of first-year undergraduate medical students ( n = 120), regarding modified directed self-learning (DSL) sessions in physiology. Students were provided with prereading assignments (faculty developed PowerPoint slides containing diagrams with incomplete labeling/flowcharts with missing steps) pertaining to the DSL topic 1 wk before the scheduled small-group DSL presentations. During DSL presentation sessions, which were facilitated by teachers, a few students individually presented learning objectives in the specified topic. Apart from that, students discussed answers for the questions in the prereading assignment. Students were also given an opportunity to use technology to support DSL, by way of involving them in Pecha Kucha (PK) talks. The impact of the modified DSL method was determined by requesting students to respond to a validated questionnaire. Frequency analysis of the responses revealed that >60% of students were positive about the modified DSL sessions improving their DSL, presentation, collaborative learning, and information retrieving skills. Students agreed that PK talks helped them to learn how to organize content (65%), present concise information (65.8%), and apply creativity (72.5%). Even though small in number, there were comments that the prereading assignments were useful for learning. The present study revealed that, even though students actively participated in modified DSL sessions, their perceptions on satisfaction and usefulness of the same toward achievement of various skills were not encouraging. The study generated significant results, which implies that undergraduate medical students should be oriented on the relevance of active learning strategies in their future studies.
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Percepción , Fisiología/educación , Aprendizaje Basado en Problemas/métodos , Lectura , Estudiantes de Medicina , Evaluación Educacional/métodos , HumanosRESUMEN
AIMS: The aim of the study was to investigate the effects of exposure to enriched environment (EE) on passive avoidance learning and hippocampal cellular morphology in rats exposed to chronic restraint stress. MATERIALS AND METHODS: Adult male albino Wistar rats were assigned into the following groups: normal control (NC) remained undisturbed in their home cages; stressed group (S) subjected to restrained stress (6 h/day) followed by housing in standard housing for 21 days; And stressed + EE (S + EE) subjected to restrained stress followed by housing in EE for 21 days. On 22nd day, six animals from each of the three groups were exposed to passive avoidance test. The remaining animals were sacrificed. Hippocampus was isolated and processed for cellular morphology using cresyl violet staining. STATISTICAL ANALYSIS USED: Data were analyzed using one-way analysis of variance followed by Tukey's multiple comparison test (post hoc). RESULTS: Stressed rats exposed to EE showed significant improvement in passive avoidance learning test compared to NC. Quantification of the surviving neurons in the hippocampal subfields and their cellular morphology revealed significant neuroprotection in S + EE in cornu ammonis-2 (CA2) neurons and CA3 hippocampal neurons. No significant changes were found in CA1 hippocampal subfield. CONCLUSIONS: The outcome of this study makes us to think the possibilities of adopting EE as an alternative strategy in brain diseases where there is chronic stress and to minimize the impairment in learning and memory.
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The effects of chronic and repeated radiofrequency electromagnetic radiation (RFEMR) exposure on spatial cognition and hippocampal architecture were investigated in prepubescent rats. Four weeks old male Wistar rats were exposed to RF-EMR (900 MHz; SAR-1.15 W/kg with peak power density of 146.60 µW/cm(2)) for 1 h/day, for 28 days. Followed by this, spatial cognition was evaluated by Morris water maze test. To evaluate the hippocampal morphology; H&E staining, cresyl violet staining, and Golgi-Cox staining were performed on hippocampal sections. CA3 pyramidal neuron morphology and surviving neuron count (in CA3 region) were studied using H&E and cresyl violet stained sections. Dendritic arborization pattern of CA3 pyramidal neuron was investigated by concentric circle method. Progressive learning abilities were found to be decreased in RF-EMR exposed rats. Memory retention test performed 24 h after the last training revealed minor spatial memory deficit in RF-EMR exposed group. However, RF-EMR exposed rats exhibited poor spatial memory retention when tested 48 h after the final trial. Hirano bodies and Granulovacuolar bodies were absent in the CA3 pyramidal neurons of different groups studied. Nevertheless, RF-EMR exposure affected the viable cell count in dorsal hippocampal CA3 region. RF-EMR exposure influenced dendritic arborization pattern of both apical and basal dendritic trees in RF-EMR exposed rats. Structural changes found in the hippocampus of RF-EMR exposed rats could be one of the possible reasons for altered cognition.
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Cognición/efectos de la radiación , Campos Electromagnéticos/efectos adversos , Radiación Electromagnética , Aprendizaje por Laberinto/efectos de la radiación , Conducta Espacial/efectos de la radiación , Factores de Edad , Animales , Región CA3 Hipocampal/patología , Región CA3 Hipocampal/efectos de la radiación , Masculino , Células Piramidales/patología , Células Piramidales/efectos de la radiación , Ratas , Ratas WistarRESUMEN
BACKGROUND: Golgi-Cox staining method is considered as one of the best neurohistological and fascinating staining techniques to reveal the cytoarchitecture of the brain. Requirement of longer time (more than a month), laborious section processing steps, requirement of sophisticated equipment's and costly ready to use kits limits extensive use of this technique. NEW METHOD: The need for a modified staining technique is to overcome some of these hurdles. Here we describe a modification of Golgi-Cox staining involving reduced impregnation time (7 days), omitting tissue dehydration steps, and alterations in section processing steps. Different impregnation duration (7 days, 14 days, 1 month, 6 months and 10 months) effects on optimized staining of dorsal hippocampus and basolateral amygdala were investigated. RESULTS: Modified Golgi-Cox staining method was found to be effective in staining rat hippocampus and amygdala. Impregnation for 7 days, 14 days and 1 month resulted in giving good results and they were comparable. However, artifacts were slightly elevated with 6 months group but not extensively. Impregnation for 10 months negatively affected the staining process. COMPARISON WITH EXISTING METHOD(S): Compared to existing methods the current method was found to be cost effective, fast, reliable and can be executed in labs where infrastructure is limited. CONCLUSIONS: Current modification considerably benefitted in obtaining better results (good clarity and lesser artifact) in a short time. Longer impregnated brain sections were found to be unsuitable for morphometric evaluation due to more stain precipitation and artifact. The modified technique can be used to study cellular architecture in other brain regions.
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Complejo Nuclear Basolateral/citología , Hipocampo/citología , Neuronas/citología , Coloración y Etiquetado/métodos , Animales , Espinas Dendríticas , Masculino , Fotomicrografía , Ratas Wistar , Coloración y Etiquetado/economía , Factores de TiempoRESUMEN
In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 µW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.
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Teléfono Celular , Radiación Electromagnética , Emociones/fisiología , Emociones/efectos de la radiación , Locomoción/fisiología , Locomoción/efectos de la radiación , Animales , Masculino , Distribución Aleatoria , Ratas , Ratas WistarRESUMEN
BACKGROUND: It is quite difficult to teach complex topics like the physiology of vestibular apparatus to undergraduate students. Understanding the orientation and mode of stimulation of receptors in vestibular apparatus is also quite challenging for the students. As faculty we attempt to use innovative methods to teach physiology and enhance student learning. PURPOSE: This article describes a simple and innovative method (student-involved demonstration approach, or SID) to teach the physiology of the vestibular apparatus to the undergraduate medical students. METHODS: The current study describes a protocol where students engage in role-play sessions in the middle of the regular didactic lectures. Effectiveness of the sessions was later evaluated by using a questionnaire and by comparing the pre-SID and post-SID test results of the students. RESULTS: The posttest score of the students was significantly higher than the pretest score, and this indicates the usefulness of SID sessions on enhancing the student learning in the class. CONCLUSIONS: Students also found this method very interesting and useful in better understanding the physiology of the vestibular apparatus.
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Educación de Pregrado en Medicina , Desempeño de Papel , Estudiantes de Medicina , Enseñanza/métodos , Vestíbulo del Laberinto/fisiología , Humanos , Fisiología/educación , Desarrollo de ProgramaRESUMEN
AIM: In the current study we evaluated adverse effects of monosodium glutamate (MSG) on memory formation and its retrieval as well as the role of ascorbic acid (Vitamin-C) in prevention of MSG-induced alteration of neurobehavioral performance in periadolescent rats. MATERIALS AND METHODS: Healthy male albino Wistar rats (4-6 weeks old), were randomly allotted in four groups. Group I: normal control, who remained in their homecage throughout the experimental period. Group II: vehicle control, who were orally administered with normal saline for three weeks. Group III: MSG, who were orally administered with aqueous solution of MSG (2 mg/g b.w/day), for three weeks. Group IV: MSG+AA, who were administered with aqueous solution of MSG, and subsequently by ascorbic acid (100 mg/kg b.w/day) orally for three weeks. After the experimental period, all animals from all groups were first tested for anxiety followed by passive avoidance behavior. RESULTS: MSG significantly altered the neurobehavioral performance in rats. The alteration manifested as less time spent on the open arm during the EPM test and shorter entrance latency to the dark compartment during the passive avoidance task. All behavioral changes were significantly prevented by simultaneous administration of ascorbic acid with MSG. CONCLUSION: The present data point to the neuroprotective role of ascorbic acid. The ascorbic acid can be used as a therapeutic agent in various cognitive deficits (Fig. 5, Ref. 25). Full Text (Free, PDF) www.bmj.sk.
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Conducta Animal/efectos de los fármacos , Aditivos Alimentarios/farmacología , Memoria/efectos de los fármacos , Glutamato de Sodio/farmacología , Vitaminas/farmacología , Animales , Ácido Ascórbico/farmacología , Reacción de Prevención/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratas , Ratas WistarRESUMEN
INTRODUCTION: The interaction of mobile phone radio-frequency electromagnetic radiation (RF-EMR) with the brain is a serious concern of our society. OBJECTIVE: We evaluated the effect of RF-EMR from mobile phones on passive avoidance behaviour and hippocampal morphology in rats. MATERIALS AND METHODS: Healthy male albino Wistar rats were exposed to RF-EMR by giving 50 missed calls (within 1 hour) per day for 4 weeks, keeping a GSM (0.9 GHz/1.8 GHz) mobile phone in vibratory mode (no ring tone) in the cage. After the experimental period, passive avoidance behaviour and hippocampal morphology were studied. RESULTS: Passive avoidance behaviour was significantly affected in mobile phone RF-EMR-exposed rats demonstrated as shorter entrance latency to the dark compartment when compared to the control rats. Marked morphological changes were also observed in the CA(3) region of the hippocampus of the mobile phone-exposed rats in comparison to the control rats. CONCLUSION: Mobile phone RF-EMR exposure significantly altered the passive avoidance behaviour and hippocampal morphology in rats.
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Reacción de Prevención/efectos de la radiación , Campos Electromagnéticos , Hipocampo/efectos de la radiación , Ondas de Radio , Animales , Teléfono Celular , Hipocampo/anatomía & histología , Masculino , Ratas , Ratas WistarRESUMEN
OBJECTIVE: Chronic stress has been shown to cause oxidative damage in the central nervous system. Although stress-induced impairments in learning and memory have been studied extensively, very few studies have investigated possible ways to prevent their ill effects. The present work was designed to study the protective effects of ascorbic acid in memory loss induced by chronic restraint stress. METHODS: Adult male Wistar rats were designated into the following groups: (i) Normal control, (ii) Ascorbic acid treatment, (iii) Vehicle control, (iv) Restraint stress, (v) Restraint stress + vehicle, and (vi) Restraint stress + ascorbic acid treatment. At the end of 21 days, animals of all groups were subjected to memory tests using Morris water maze and passive avoidance apparatus. Then, the results obtained were compared between the experimental groups. RESULTS: Rats exposed to restraint stress alone and those pretreated with vehicle solution before restrained stress showed deficits in learning and impaired memory retention in the memory tests when compared to animals in other experimental groups. Animals pretreated with ascorbic acid before restraining showed significant improvement in memory retention in the same memory tests. CONCLUSIONS: Results of this study suggest the possibility of using ascorbic acid as a dietary supplement to prevent stress-induced memory impairments.