Objective  To observe the effect of lanthanum chloride (LaCl₃) on excitability of hippocampus astrocytes and to explore the mechanism of the neurotoxic effect.

  Methods  Forty female Wistar rats were randomly divided into 5 groups; the rats of the 4 experimental groups were supplied with distilled drinking water containing LaCl₃ at various concentration (0.125%, 0.250%, 0.500%, and 1.000%) and those of the control group with uncontaminated distilled water during the period from pregnancy till the end of first weaning month. Intracellular bivalent calcium ion (Ca²⁺) concentration in hippocampal neurons of the offspring rats was detected with Fura-2 fluorescent probe method and the inositol 1,4,5-trisphosphate (IP₃) content was determined with enzyme-linked immunosorbent assay (ELISA). The mRNA transcription of metabotropic glutamate receptor 5 (mGluR5), phospholipase C (PLC), and connexin (Cx43) were determined with real-time quantitative PCR; the protein expression of mGluR5, PLC, and Cx43 were detected with Western blot.

  Results  Compared with those of the control rats, the Ca²⁺ concentration and IP₃ content in hippocampal neurons of the experimental rats increased with the increment of LaCl₃ in a dose-effect manner (both P < 0.05); while, the expressions of mGluR5, PLC, and Cx43 mRNA and protein in hippocampal neurons of experimental rats were all up-regulated with the increment of LaCl₃ in a dose-effect manner (P < 0.05 for all).

  Conclusion  Lanthanum chloride can cause excessive excitability of hippocampal astrocytes and induce neuronal damage in offspring rats with maternal Lanthanum chloride exposure.