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PFASs significantly altered swimming behaviour in zebrafish embryos. Some short-chain PFASs caused behaviour toxicity, but not acute toxicity. A PFAS mixture was less potent than some individual PFASs. Bioconcentration factor (BCF) after six days was 0.9e2700 for individual PFASs. Toxicity and BCF were related to perfluorocarbon chain length and functional group.

Spatial behaviour was investigated using a spatial learning task based on the Radial Arm Maze, the Morris Water Maze, and open-field search-task procedures. Ninety-six healthy children from six age groups (3, 4, 5, 7, 10 and 12 years) with no history of CNS disorders were studied with respect to the emergence of position-, cue- and place responses. Participants were to detect x out of n hidden locations, frames of reference could be varied systematically, and three spatial memory errors and speed of navigation were recorded automatically. Task difficulties were equivalent for each age group. Results showed that navigational place learning was fully developed by the age of 10, whereas participants relied on cue orientation up to age 7. Even in the youngest group, the task could be achieved without relying on egocentric orientation, provided that proximal cues were presented. Most of the errors were of the reference memory type, whereas working memory errors were extremely rare. Speed of navigation markedly improved between age 5 and 7. An additional experiment showed that navigational place-learning behaviour was clearly dependent on distal cues. A third study showed that in young adults, learning of the spatial layout improved, but performance on the place task did not improve any further. No sex differences were observed.

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