Neurological alterations in adult female rats developmentally exposed to a glyphosate-based herbicide: Potential role of the immune system

Despite the increasing evidence about the adverse consequences of early exposure to Glyphosate (Gly) and Gly-based herbicides (GlyBHs) on the central nervous system (CNS), little is known about the effects of this herbicide on the developing immune system. We have previously described that oral exposure of rats to a GlyBH during pregnancy and lactation induces neurobehavioral alterations, brain oxidative stress imbalance, and impairment in the activity of enzymes involved in the glutamatergic and cholinergic systems in adulthood. The purpose of this study was to investigate further the mechanisms of neurotoxicity exerted by GlyBHs and to explore a possible link between their effects on the CNS and the immune system. For this purpose, pregnant Wistar rats were orally exposed to 0.4 % GlyBH from gestational day 0 until weaning (postnatal day (PND) 21), and a series of behavioural and biochemical analyses were conducted in PND90 female pups. Haematological and serological parameters were affected by exposure to the herbicide. In addition, GlyBH altered lactate dehydrogenase (LDH) activity and the redox status in specific brain areas, and decreased the number of astrocytes in the hippocampus of perinatally exposed rats. Finally, GlyBH-treatment induced a depressive-like behaviour evaluated by the forced swim test. Taken together, the findings of the present study demonstrate that exposure to a Gly-containing herbicide during pregnancy and lactation induced long-lasting changes in the immune system of 90-day-old female offspring, which in turn could affect their CNS.