Resumo

BENITEZ-DIAZ, Pedro  e  MIRANDA-CONTRERAS, Leticia. Effects of prenatal expossure to paraquat on the development of amino acid synaptic transmission in mouse cerebral parietal cortex. Invest. clín [online]. 2009, vol.50, n.4, pp.465-478. ISSN 0535-5133.

The effects of prenatal expossure to paraquat (PQ) were studied on postnatal development of mouse parietal cerebral cortex, in particular, the ontogenesis of amino acid synaptic transmission. Pregnant NMRI mice were separated into two groups: the experimental group received 5 doses of 10mg PQ/kg body weight, between days of gestation (G)12 and G20, whereas the control group received physiological saline solution. Levels of neurotransmitter amino acids: Asp, Glu, Gly, GABA and Tau were determined by HPLC between postnatal (P) days P1 and P30. Between P3 and P15, a significant increment in the levels of excitatory amino acids, Asp and Glu, were observed in mice exposed to PQ, as compared with the control group. With respect to the inhibitory neurotransmitter levels, in the group exposed to PQ, the more important changes were observed in Gly between P1 and P15. In relation to taurine, its levels remained significantly higher between P1 and P7 with respect to the control group. It is important to emphasize that at P30, the levels of all neurotransmitters in the experimental group were significantly lower than those of control. In conclusion, prenatal exposure to PQ caused neurotoxicity in the developing mouse parietal cortex, as shown by the alterations in the basal levels of amino acid neurotransmitters, with the excitatory predominating over inhibitory neurotransmission, throughout the studied developmental period. These alterations could indicate the occurrence of important cortical injuries, such as decrement in some neuronal populations, inadequate formation of intrinsic cortical circuits and alterations in synaptogenic processes.

Palavras-chave : Paraquat; pesticides; amino acid neurotransmitters; parietal cerebral cortex development; mouse.

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