Impairment of cerebral glucose metabolism parallels learning and memory dysfunctions after intracerebral streptozotocin

In early-onset Alzheimer’s disease, the cerebral glucose metabolism is disturbed in a characteristic manner. Here, we attempted to mimick these alterations by intracerebral injection of the pancreatic islet cell toxin streptozotocin (STZ) into the rat brain ventricles. This treatment resulted in a reduced arteriovenous difference (AVD) of glucose, an increased AVD of lactate, whereas the AVDs of oxygen and carbon dioxide remained unchanged. In addition, learning and memory functions were impaired. These alterations may be related to a disturbance of the local action of insulin on the brain. Furthermore, the approach reported here may provide a model for the study of the early pathogenetic events of Alzheimer’s disease.