Publications by authors named "Cindy S Roegge"

Bisphenol A (BPA) is an important industrial chemical used as the monomer for polycarbonate plastic and in epoxy resins for food can liners. Worldwide biomonitoring studies consistently find a high prevalence of BPA conjugates in urine (>90%) in amounts consistent with aggregate exposure at levels below 1 μg/kg bw/d. The current study used LC/MS/MS to measure concurrently the pharmacokinetics of aglycone (active) and conjugated (inactive) deuterated BPA (d6) in maternal and fetal rhesus monkey serum, amniotic fluid, and placenta following intravenous injection in the dam (100 μg/kg bw).

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Developmental exposure to the organophosphorus pesticides chlorpyrifos and diazinon (DZN) alters serotonergic synaptic function at doses below the threshold for cholinesterase inhibition, however there are some indications that the two agents may differ in several important attributes. Previously, we found that low-dose chlorpyrifos exposure in neonatal rats causes lasting changes in emotional response and in the current study we did a comparable evaluation for DZN. Male and female Sprague-Dawley rat pups (N=10-12 of each sex per treatment group) were given 0, 0.

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Article Synopsis
  • Developmental exposure to organophosphorous insecticides (specifically diazinon) can lead to lasting cognitive deficits, even at low doses that don't significantly inhibit cholinesterase.
  • Rats exposed to diazinon during early postnatal days displayed hyperactivity and impaired spatial learning, particularly at a low dose, while also showing altered responses based on sex.
  • These findings suggest that neurocognitive impairments from insecticide exposure may occur through mechanisms beyond just cholinesterase inhibition, indicating a complex relationship between dose and behavioral effects.
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Histamine H(1) blockade is one of the more prominent actions of the multi-receptor acting antipsychotic clozapine. It is currently not known how much this H(1) antagonism of clozapine contributes to the therapeutic or adverse side effects of clozapine. The current studies with Sprague-Dawley rats were conducted to determine the participation of histaminergic H(1) receptor subtype in sensorimotor plasticity and memory function affected by clozapine using tests of prepulse inhibition (PPI) and radial-arm maze choice accuracy.

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Recent studies raise concern for combined exposure to polychlorinated biphenyls (PCBs) and methylmercury (MeHg), two environmental contaminants that are found in fish and seafood. Past accidental poisonings in humans show that exposure to high levels of either contaminant is associated with motor impairments, including alterations in cerebellar functions such as balance and coordination. Epidemiological studies of lower level exposures suggest some neuromotor impairment in exposed children, but the majority of these studies have focused on cognitive endpoints rather than examining a full-range of motor function.

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We recently reported that rats exposed to PCBs and MeHg during development were impaired on the rotating rod, a test of balance and coordination that is often indicative of cerebellar damage. In addition, developmental PCB exposure is known to dramatically reduce circulating thyroid hormone concentrations, which may have a negative impact on cerebellar development. Therefore, we investigated the effects of combined PCB and MeHg exposure on Purkinje cells and the cerebellum.

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Dietary n-3 fatty acid (FA) deficiencies during development can cause learning and memory impairments, but the functional effects of dietary n-6 FA deficiencies, reflected in a lowered n-6/n-3 ratio, are less clear. We investigated the effects of maternal diets containing fish oils, resulting in lowered n-6/n-3 ratios, on a spatial working memory task in their offspring. Starting on gestational day 6, Sprague-Dawley timed-pregnant rats were placed on one of three experimental diets: control (unadulterated powdered rat chow), Pacific Ocean (PO) fish (powdered rat chow containing 20% (w/w) lyophilized PO salmon), or PO oil (powdered rat chow containing 6% (w/w) oil extracted from PO salmon).

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Article Synopsis
  • Epidemiological and lab studies suggest that polychlorinated biphenyls (PCBs) and methyl mercury (MeHg) may negatively affect nervous system function, particularly the cerebellum which is crucial for balance and coordination.
  • This research examined the impacts of developmental exposure to PCBs, MeHg, or their combination on motor tasks in Long-Evans rats, focusing on cerebellar functions.
  • Results showed that rats exposed to both PCBs and MeHg were impaired in a task requiring them to walk across a rotating rod, while those exposed to PCBs alone showed some impairment, but MeHg exposure did not significantly affect performance compared to controls, indicating potential additive neurotoxic effects.
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