The effects of intra-hippocampal manipulation of glycine receptors on the reconsolidation of recent and late long-term spatial memory were evaluated and assessed in the Morris water maze. The results obtained from the intra-hippocampal infusion of glycine and taurine demonstrated that taurine at a 100 nmol/side dose impaired the reconsolidation of recent and late long-term spatial memory. In comparison, at a dose of 10 nmol/side, it only affected the reconsolidation of late long-term spatial memory, reinforcing that there are differences between molecular mechanisms underlying recent and late long-term memory reconsolidation. On the other hand, glycine impaired the reconsolidation of early and late spatial memory when infused at a dose of 10 nmol/side, but not at a dose of 100 nmol/side, unless it is co-infused with an allosteric site antagonist of the NMDA receptor. Altogether these results show that glycine acting in situ in the hippocampal CA1 region exerts a pharmacological effect on U-curve, which can be explained by its concomitant action on its ionotropic receptor GlyR and on its NMDA receptor co-agonist site.