Short-chain PFAS exposure during gestation and breastfeeding alters learning and memory in adulthood: possible mechanisms related to brain development

Luca Lorenzini^1,2Marzia Moretti¹Claudia Zanardello³Federica Gallocchio³Vito Antonio Baldassarro^1,2Alessandra Moressa³Lorenzo Zanella¹Michele Sannia⁴Greta Foiani³Corinne Quadalti^2,5,6Maura Cescatti⁴Valentina Burato⁴Margherita Soncin³Marzia Mancin³LUCIANA GIARDINO^1,2Franco Mutinelli³Marta Vascellari^3*Laura Calza^2,6*

• ¹Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
• ²Interdepartmental Centre for Industrial Research in Health Sciences and Technologies - CIRI Health Sciences and Technologies, University of Bologna, Bologna, Italy
• ³Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Italy
• ⁴IRET ETS Foundation, Ozzano Emilia (BO), Italy
• ⁵University of Bologna, Bologna, Italy
• ⁶Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy

Exposure to long-chain perfluoroalkyl substances (PFASs) during development has been consistently associated with cognitive impairment and behavioural changes in humans. These concerns have led to regulatory restrictions and a shift towards short-chain PFASs as alternatives. However, experimental evidence on the neurodevelopmental impact of short-chain PFASs remains scarce, despite their increasing detection in drinking water and human biomonitoring studies. This study provides the first experimental evidence of the neurodevelopmental toxicity of maternal exposure to the short-chain PFASs GenX and PFBA, administered before mating, throughout gestation, and during lactation. In a rat model, offspring from exposed dams displayed significant impairments in spatial learning and cognitive flexibility in the Morris water maze. Mechanistic investigations on PFBA exposure ex vivo revealed delayed neuronal maturation, reduced expression of MAP2, PSD95 and VGLUT. Impaired neurogenesis persisted into adulthood in the hippocampus, as shown by upregulation of nestin and downregulation of doublecortin, together with dysregulated expression of neuroinflammatory genes in the hippocampus for both tested molecules. Our findings indicate that even short-chain PFASs, currently considered safer substitutes, may disrupt brain development, leading to persistent neuroinflammation and impaired cognitive function. These results highlight an urgent need to reassess the developmental safety of short-chain PFASs and to include neurodevelopmental endpoints in future risk assessments and regulatory policies.