Manganese is of growing concern as a toxic air pollutant. It is readily transported from the olfactory epithelium to the olfactory bulb, and unlike other metals, it is transported transynaptically to structures deep within the brain. However, little is known regarding the possible effect of nonoccupational exposure to manganese on olfactory function. Using the Sniffin' Sticks test battery, we c...

Bacillus sp. strain SG-1 is a marine bacterial species isolated from a near-shore manganese sediment sample. Its mature dormant spores promote the oxidation of Mn to MnO(2). By quantifying the amounts of immobilized and oxidized manganese, it was established that bound manganese was almost instantaneously oxidized. When the final oxidation of manganese by the spores was partly inhibited by NaN(...

Brain extracellular concentrations of amino acids (e.g. aspartate, glutamate, taurine) and divalent metals (e.g. zinc, copper, manganese) are primarily regulated by astrocytes. Adequate glutamate homeostasis is essential for the normal functioning of the central nervous system (CNS). Glutamate is of central importance for nitrogen metabolism and, along with aspartate, is the primary mediator of...

Recognizing the similarities between Huntington's disease (HD) pathophysiology and the neurotoxicology of various metals, we hypothesized that they may exhibit disease-toxicant interactions revealing cellular pathways underlying neurodegeneration. Here, we utilize metals and the STHdh mouse striatal cell line model of HD to perform a gene-environment interaction screen. We report that striatal ...

During infection the host imposes manganese and zinc starvation on invading pathogens. Despite this, Staphylococcus aureus and other successful pathogens remain capable of causing devastating disease. However, how these invaders adapt to host-imposed metal starvation and overcome nutritional immunity remains unknown. We report that ArlRS, a global staphylococcal virulence regulator, enhances th...

Manganese overexposure in non-human primates and humans causes a neurodegenerative disorder called manganism thought to be related to an accumulation of the metal in the basal ganglia. Here, we assess changes in the concentration of manganese in regions of the brain of a non-human primate (the common marmoset, Callithrix jacchus) following four systemic injections of 30 mg/kg MnCl2 H2O in the t...

Determining the manganese concentration in shells of freshwater bivalves provides a unique way to obtain information about climate and environmental changes during time-intervals that pre-date instrumental data records. This approach, however, relies on a thorough understanding of how manganese is incorporated into the shell material -a point that remained controversial so far. Here we clarify ...

BACKGROUND Manganese is an essential nutrient, but in excess it can be a potent neurotoxicant. Despite the common occurrence of manganese in groundwater, the risks associated with this source of exposure are largely unknown. OBJECTIVES Our first aim was to assess the relations between exposure to manganese from drinking water and children's intelligence quotient (IQ). Second, we examined the ...

Manganese homeostasis involves coordinated regulation of specific proteins involved in manganese influx and efflux. However, the proteins that are involved in detoxification/efflux have not been completely resolved nor has the basis by which they select their metal substrate. Here, we compared six proteins, which were reported to be involved in manganese detoxification/efflux, by evaluating the...

Perception and response to nutritional iron availability by bacteria are essential to control cellular iron homeostasis. The Irr protein from Bradyrhizobium japonicum senses iron through the status of heme biosynthesis to globally regulate iron-dependent gene expression. Heme binds directly to Irr to trigger its degradation. Here, we show that severe manganese limitation created by growth of a ...