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- Buratovic, Sonja, et al.
(författare)
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Comparison of single and repeated exposure to low doses of pyrethroids, permethrin and bioallethrin, during neonatal brain development on adult spontaneous behaviour
- 2012
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Konferensbidrag (refereegranskat)abstract
- Permethrin and bioallethrin belong to the Type 1 class of pyrethroid pesticides. The primary mechanism of action is interference with nerve membrane sodium channels that results in increased neuronal activity. We have earlier reported on developmental neurotoxic effects after repeated, PND 10 to PND16, neonatal exposure to pyrethroids. The effects were manifested as altered spontaneous behavior, hyperactivity and reduced cognitive function and changes in cholinergic muscarinic/nicotinic receptors in the cerebral cortex of neonatal and adult mice. The present study was undertaken to compare repeated and single exposure to permethrin and bioallethrin during the neonatal brain growth spurt (BGS) on adult spontaneous behavior in a novel home environment. Neonatal NMRI male mice were given permethrin, orally (0.55; 3.3; 6.6 mg/kg bw/day) on PND 10-14, or just a single oral dose of 6.6 mg/kg bw on PND 10. Bioallethrin was given as a single oral dose of 0.7 mg/kg bw on PND 10, and compared to earlier published data on repeated exposure. Mice serving as controls received the 20 % fat emulsion vehicle. Spontaneous behavior test (locomotion, rearing, total activity) in 2-month-old mice revealed a significant higher activity in mice exposed to repeated doses of 6.6 mg permethrin, as well in mice just receiving a single 6.6 mg dose of permethrin. No significant difference was observed between repeated and single exposure. A single dose of 0.7 mg bioallethrin on PND 10 caused the same effects as a repeated dose of 0.7 mg between PND 10 to PND 16. This demonstrates that a single dose of these pyrethroids can cause the same developmental neurotoxic effects as that seen following repeated doses over one week during the neonatal BGS period in mouse. This research provides is consistent with previous findings that exposure during the BGS can result in persistent behavioral defects.
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| 2. |
- Buratovic, Sonja, et al.
(författare)
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Developmental exposure to PBDE 209 alters adult susceptibility to paraoxon and nicotine : gender and neurobehavioural analysis
- 2011
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Konferensbidrag (refereegranskat)abstract
- Newborns, infants and children can be indirectly and directly exposed to PBDEs. This exposure coincides with a period of rapid brain development. Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame-retardants in polymers, especially in electric appliances.A concern is that these compounds are present at a higher level in newborns and toddlers than in the average adult individual, especially the highly brominated PBDEs. We have earlier reported that neonatal exposure to toxicants can lead to an increased susceptibility of the cholinergic system at adult age. The present study was undertaken to investigate whether neonatal exposure of male and female mice to PBDE 209 alters the adult susceptibility to the organophosphorous compound, paraoxon, and to nicotine, respectively.. Neonatal, 3-day-old, NMRI mice were exposed to PBDE 209 (2,2´,3,3´,4,4´,5,5´,6,6´-decaBDE at 1.4, 6.0 and 14 µmol/kg bw). At two months of age male mice were exposed to paraoxon (0.25 mg/kg bw, every 2nd day for 7 days) and female mice exposed to nicotine. At the age of 2 months male and female mice were observed for spontaneous behaviour in a novel home environment, before and after adult exposure to paraoxon and nicotine, respectively. Adult male and female mice neonatally exposed to PBDE 209 showed significant impaired spontaneous behaviour. Male mice neonatally exposed to PBDE 209 and to paraoxon as adults developed additional defect spontaneous behaviour and lack of habituation. Female mice neonatally exposed to PBDE 209 showed an increased susceptibility to nicotine, where PBDE 209 exposed mice responded with a decrease in activity to nicotine whereas control mice responded with increased activity. The present study shows that PBDE 209 can induce developmental neurobehavioural defects in both male and female mice. Neonatal exposure to PBDE 209 caused also increased susceptibility in adult mice to paraoxon and nicotine. All these effects were dose response related.
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| 6. |
- Buratovic, Sonja, et al.
(författare)
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Neonatal exposure to a single low dose of ionising radiation causes persistent disruptions in cognitive abilities and increased levels of tau in mice
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ionising radiation (IR) is extensively used in the medical field for treatment and diagnostics. Concern has been raised about possible negative consequences from low dose exposure to IR during critical phases of perinatal and/or neonatal brain development. The brain growth spurt, which is characterized by maturation of axonal and dendritic outgrowth, establishment of neural connections and acquisition of new motor and sensory abilities, occurs perinatally in humans and neonatally in mice. By using the neonatal mouse as an animal model we are able to study the effect of IR during early periods of brain development and which consequences it has for the adult animal.Neonatal NMRI mice were irradiated (0; 0.35 and 0.5 Gy) at one single occasion on postnatal day 10. At 2- and 4-months of age, spontaneous behaviour was tested in a novel home environment and parameters observed were locomotion, rearing and total activity. Analyses of important neuroproteins in cerebral cortex were performed 24h following irradiation (0 and 0.5 Gy) and at 6-months of age.Observations of spontaneous behaviour revealed a significantly deranged behaviour in 2- and 4-month old mice of both sexes irradiated with 0.35 or 0.5 Gy in a dose response related manner. The observed reduced activity during the beginning of the test period and increased activity at the end of the test period indicates a lack of habituation capacity and disrupted cognitive functions. Neuroprotein analyses of cerebral cortex 24h after irradiation and at 6-months of age showed a significantly increased level of tau in mice irradiated with 0.5 Gy compared to controls. This demonstrates that a single dose of IR, given at a defined critical period during brain development, is sufficient to cause persistently reduced cognitive functions and increased levels of tau in mice.
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