Early restriction of nutrients during the perinatal period has marked repercussions on CNS ontogeny, leading to impaired functions. This study investigated the effects of pre- and postnatal (up to 75 days) undernutrition (diet: 8% protein; normonourished group: 25% protein) on some glutamatergic and behavioral parameters of rats. Undernutrition reduced: (i) seizures caused by ICV quinolinic acid (QA) administration; (ii) Na-independent [3H]glutamate binding in cell plasma membranes of cerebral cortex, and (ii) basal [3H]glutamate release from synaptosomal preparation. Behavioral parameters related to locomotion, anxiety, or memory were not affected. These results indicate that our model of undernutrition decreased the sensitivity to QA as convulsing agent and point to some putative glutamatergic parameters involved in this effect.