Glyphosate exposure impairs neuronal connectivity and spatial learning in rats.

LUNA, SEBASTIAN; ROSSO SILVANA

Córdoba

Congreso; XXXIII Reunión Anual SAN 2018; 2018

Sociedad Argentina de Investigaciones en Neurociencia

The developing nervous system is highly susceptible to damage caused by exposure to environmental contaminants. Glyphosate (gly) is the active ingredient of a number of broad-spectrum herbicide formulations, widely used all over the world to control weeds. Previous studies have demonstrated that gly induces neurotoxicity in mammals. Therefore, the cellular mechanism by which it induces neurotoxicity needs to be determined.We evaluated hippocampus-dependent spatial learning by the Morris water maze test and found that acquisition is impaired in rats exposed to gly during a critical period of synaptogenesis (first three postnatal weeks of life). These animals also showed alterations in the expression of synaptic proteins in the hippocampus such as PSD-95 and Synapsin I.To further analyse the effect of gly on neuronal connectivity we used hippocampal cultured neurons to study the maturation of dendrite arbors in 17 days in vitro (DIV) control and treated neurons. We observed that gly exposure markedly decreased dendritic length and complexity in a dose dependent manner. Then, we studied whether the herbicide impairs the development of dendritic spines in 17 and 20 DIV cultured neurons. Results showed that exposure to gly induces a decrease in spine density and maturation. Furthermore, we observed a defect in the number of synaptic clusters.In conclusion these findings suggest that gly exposure alters neuronal connectivity both in vivo and in vitro impairing complex cognitive behavior.