Maternal Exposure to Atrazine Induces Hippocampus Neuroinflammation in Mice Offspring and Impairs Their Learning and Spatial Memory

Atrazine as an herbicide is widely used. Atrazine can be transferred from mother to their offspring via the placenta and the breast milk. Entrance of atrazine to the body may produce neuroinflammation in which effect on learning and memory. In this regard, we evaluated the effects of atrazine exposure during pregnancy and lactation on spatial memory and learning in mice offspring. Materials and Methods: 24 Pregnant Balb/C mice were divided into three groups including atrazine 10mg/kg, atrazine 50mg/kg and normal saline (n=8). Daily administration of atrazine or normal saline began from gestational day (GD) 6 and continued until postnatal day (PD) 23 via gavage. At the end of the administration, from each mother two male offspring were selected randomly and then their brain were removed, fixed in formalin and prepared according to routine histological methods. The tissue sections stained with TUNEL and Toluidine blue to detect apoptotic cellsand dark neurons in their hippocampus respectively. Finally, the stained slides were photographed and apoptotic cells and dark neurons were counted per unit area in the CA1, CA2, CA3 and DG hippocampus regions by using the soteriological methods. Moreover, remaining offspring were weaned and housed until adulthood (PD75) and then two male offspring from each mother were selected randomly for learning andspatial memory assessment by using Morris water maze (MWM) and passive avoidance (PA) tests. Results: The results of this study showed that apoptotic cells and dark neurons were significantly increased in CA1 and CA3 regions of the mice offspring hippocampus in atrazineexposed groups comparing to normal saline group (p<0.05). Furthermore, the results of the behavioral tests indicated that learning and memory of offspring in the atrazine groups was significantly lower than normal saline group (p<0.05). Conclusion: impairment ofmemory and learning in behavioral tests and also the significant alteration of apoptotic cells and dark neurons in the hippocampus of atrazine groups, may be resulted from inflammation in the brain of male offspring.