Gender‐specific desensitization of group I metabotropic glutamate receptors after maternal l ‐glutamate intake during lactation

In the present work we have studied the effect of maternal intake of l ‐Glutamate ( l ‐Glu) (1 g/L) during lactation on group I mGluR transduction pathway in brain plasma membrane from 15 days‐old neonates. Results obtained have shown that maternal l ‐glutamate intake did not significantly affect neither weights of pups nor negative geotaxis reflex, an index of neurobehavioral development, but increased l ‐Glu plasma level in both male and female neonates. In male neonates, maternal l ‐Glu intake evoked a loss of mGluR 1 whereas no variation on mGluR 5 was observed as revealed by Western‐blotting assay. The loss of mGlu 1 R was accompanied by a decrease on l ‐Glu‐stimulated phospholipase C activity suggesting, therefore, a loss of group I mGluR functionality. Concerning female neonates, no variations were detected neither mGluR 1 nor mGluR 5 and group I mGluR functionality was also preserved.