The effect of electromagnetic radiation in the mobile phone range on the behaviour of the rat

Abstract Electromagnetic radiation (EMR) is emitted from electromagnetic fields that surround power lines, household appliances and mobile phones. Research has shown that there are connections between EMR exposure and cancer and also that exposure to EMR may result in structural damage to neurons. In a study by Salford et al. (Environ Health Perspect 111:881-883, 2003) the authors demonstrated the presence of strongly stained areas in the brains of rats that were exposed to mobile phone EMR. These darker neurons were particularly prevalent in the hippocampal area of the brain. The aim of our study was to further investigate the effects of EMR. Since the hippocampus is involved in learning and memory and emotional states, we hypothesised that EMR will have a negative impact on the subject's mood and ability to learn. We subsequently performed behavioural, histological and biochemical tests on exposed and unexposed male and female rats to determine the effects of EMR on learning and memory, emotional states and corticosterone levels. We found no significant differences in the spatial memory test, and morphological assessment of the brain also yielded non-significant differences between the groups. However, in some exposed animals there were decreased locomotor activity, increased grooming and a tendency of increased basal corticosterone levels. These findings suggested that EMR exposure may lead to abnormal brain functioning

Boundary work: becoming middle class in suburban Dar es Salaam

Suburban space provides a useful window onto contemporary class practices in Africa, where it is difficult to identify social classes on the basis of income or occupation. In this article I argue that the middle classes and the suburbs are mutually constitutive in the Tanzanian city of Dar es Salaam. Using interviews with residents and local government officials in the city's northern suburbs, I discuss the material and representational practices of middle-class boundary work in relation to land and landscape. If the middle classes do not presently constitute a coherent political-economic force, they are nevertheless transforming the city's former northern peri-urban zones into desirable suburban residential neighbourhoods

Exposure to Early Life Stress Results in Epigenetic Changes in Neurotrophic Factor Gene Expression in a Parkinsonian Rat Model

Early life adversity increases the risk of mental disorders later in life. Chronic early life stress may alter neurotrophic factor gene expression including those for brain derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF) that are important in neuronal growth, survival, and maintenance. Maternal separation was used in this study to model early life stress. Following unilateral injection of a mild dose of 6-hydroxydopamine (6-OHDA), we measured corticosterone (CORT) in the blood and striatum of stressed and nonstressed rats; we also measured DNA methylation and BDNF and GDNF gene expression in the striatum using real time PCR. In the presence of stress, we found that there was increased corticosterone concentration in both blood and striatal tissue. Further to this, we found higher DNA methylation and decreased neurotrophic factor gene expression. 6-OHDA lesion increased neurotrophic factor gene expression in both stressed and nonstressed rats but this increase was higher in the nonstressed rats. Our results suggest that exposure to early postnatal stress increases corticosterone concentration which leads to increased DNA methylation. This effect results in decreased BDNF and GDNF gene expression in the striatum leading to decreased protection against subsequent insults later in life

Dielectric Constant and Conductivity of Blood Plasma: Possible Novel Biomarkers for Alzheimer’s Disease

Alzheimer’s disease is a complex debilitating neurodegenerative disease for which there is no cure. The lack of reliable biomarkers for Alzheimer’s disease has made the evaluation of the efficacy of new treatments difficult and reliant on only clinical symptoms. In an aged population where cognitive function may be deteriorating for other reasons, the dependence on clinical symptoms is also unreliable. However, it is well established that infusion of β-amyloid into the dorsal hippocampus of rats leads to cognitive impairment in a rat model of Alzheimer’s disease. Moreover, the blood plasma of β-amyloid-lesioned rats exhibits a distinct variation of the dielectric constant and conductivity when compared to that of normal rats in a time-dependent manner. These two electric parameters of blood plasma may therefore act as potential biomarkers for dementia due to Alzheimer’s disease. This review is aimed at highlighting evidences that support blood plasma electrical properties, e.g., dielectric constant and conductivity as possible novel biomarkers for the early development and progression of dementia due to Alzheimer’s disease

Mammalian fauna of indigenous forest in the Transkei region of South Africa:An overdue survey

The Transkei region of the Eastern Cape has received little attention from mammalian ecologists. This paper describes the presence and absence of mammalian species in Afromontane, Pondoland and south coast indigenous forests using variable width transects and explores the causes of observed differences. The region maintains a rich and diverse mammalian fauna, although differences between forest types exist. Ungulates (bushbuck, Tragelaphus scriptus; common duiker, Sylvicapra grimmia; and blue duiker, Cephalophus monticola)and fossorially-foraging (bushpigs, porcupines and moles/molerats) species are relatively more abundant in south coast forests than in Afromontane or Pondoland forest types. This may be explained by the management practices of these nature reserves compared to state forest.</p

Long-Term Treatment with Fluvoxamine Decreases Nonmotor Symptoms and Dopamine Depletion in a Postnatal Stress Rat Model of Parkinson’s Disease

Nonmotor symptoms (NMS) such as anxiety, depression, and cognitive deficits are frequently observed in Parkinson’s disease (PD) and precede the onset of motor symptoms by years. We have recently explored the short-term effects of Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI) on dopaminergic neurons in a parkinsonian rat model. Here, we report the long-term effects of Fluvoxamine, on early-life stress-induced changes in the brain and behavior. We specifically evaluated the effects of Fluvoxamine on brain mechanisms that contribute to NMS associated with PD in a unilateral 6-hydroxydopamine-lesioned rat model. A 14-day early postnatal maternal separation protocol was applied to model early-life stress followed by unilateral intracerebral infusion of 6-hydroxydopamine (6-OHDA) to model aspects of parkinsonism in rats. The anxiolytic, antidepressant, and cognitive effects of Fluvoxamine were confirmed using the elevated plus-maze (EPM) test, sucrose preference test (SPT), and Morris water maze (MWM) test. Further to that, our results showed that animals exposed to early-life stress displayed increased plasma corticosterone and malondialdehyde (MDA) levels which were attenuated by Fluvoxamine treatment. A 6-OHDA lesion effect was evidenced by impairment in the limb-use asymmetry test as well as decreased dopamine (DA) and serotonin levels in the striatum, prefrontal cortex, and hippocampus. These effects were surprisingly attenuated by Fluvoxamine treatment in all treated rats. This study is the first to suggest that early and long-term treatment of neuropsychological diseases with Fluvoxamine may decrease the vulnerability of dopaminergic neurons that degenerate in the course of PD

Mammalian fauna of indigenous forest in the Transkei region of South Africa:An overdue survey

The Transkei region of the Eastern Cape has received little attention from mammalian ecologists. This paper describes the presence and absence of mammalian species in Afromontane, Pondoland and south coast indigenous forests using variable width transects and explores the causes of observed differences. The region maintains a rich and diverse mammalian fauna, although differences between forest types exist. Ungulates (bushbuck, Tragelaphus scriptus; common duiker, Sylvicapra grimmia; and blue duiker, Cephalophus monticola)and fossorially-foraging (bushpigs, porcupines and moles/molerats) species are relatively more abundant in south coast forests than in Afromontane or Pondoland forest types. This may be explained by the management practices of these nature reserves compared to state forest.</p

Effect of long-term administration of antiretroviral drugs (Tenofovir and Nevirapine) on neuroinflammation and neuroplasticity in mouse hippocampi

The use of combination antiretroviral therapy (cART) has been successful in suppressing HIV-1 replication and restoring peripheral immune functioning in HIV-infected individuals. Despite these advances in the management of HIV, neurocognitive impairments continue to be diagnosed in HIV-infected patients on treatment, even when the viral load is low. Of interest is the observation that deficiencies in brain function in these individuals are marked by a persistent presence of neuroinflammation. Therefore, in this study we investigated whether long-term exposure to ART could contribute to neuroinflammation. Mice were subsequently administered a daily single dose of either Tenofovir disoproxil fumarate or Nevirapine orally for 8 weeks. After treatment, hippocampal tissue was collected from the brains of drug-treated and control mice and the levels of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and brain-derived neurotrophic factor (BDNF) determined. Our results showed that administration of Tenofovir disoproxil fumarate and Nevirapine induced astrogliosis and up-regulated IL-1β and TNF-α. In addition, we found that Nevirapine reduced the expression of BDNF. Together these results suggest that Nevirapine promotes inflammatory and reduces neuroprotective processes in the hippocampus of mice. Our findings therefore highlight the potential of ART to be harmful to the brain and as such these drugs may contribute to the development of HIV-associated neurocognitive disorder (HAND)