Fig. 1.

Spatial learning and skill retention test in the Morris water maze. Sham surgery – bilateral administration of a Ringer’s solution into the cerebral ventricles of rats plus subchronic intraperitoneal administration of distilled water. Surgery – bilateral administration of streptozotocin dissolved in the Ringer’s solution into the cerebral ventricles of rats plus subchronic intraperitoneal administration of distilled water. Surgery + GK-2 – bilateral administration of streptozotocin dissolved in the Ringer’s solution into the cerebral ventricles of rats plus subchronic intraperitoneal administration of dipeptide GK-2. Surgery + memantine – bilateral administration of streptozotocin dissolved in the Ringer’s solution into the cerebral ventricles of rats plus subchronic intraperitoneal administration of memantine. The EL per four placements within 1 day were averaged for each animal. The data are presented as medians and interquartile ranges