The influence of intracerebral streptozotocin and/or cadmium on memory processes in mice exposed to transient cerebral oligemia.

The aim of the study was to examine the effects of simultaneous acute exposure to cadmium (Cd) and in the presence of streptozotozin (STZ) on the central nervous system (CNS) memory processes in mice subjected to transient brain ischemia. In order to obtain transient brain ischemia, operative occlusion of common carotid arteries for 30 min was performed. Cadmium chloride was administered intraperitoneally (ip) after the surgery at a single dose of 0.1 LD(50) (LD(50) = 14 mg/kg). Disturbances in glucose metabolism in the brain tissue were induced by bilateral intracerebral administration of STZ, a drug that inhibits the function of a neuronal insulin receptor. Long-term memory was evaluated by means of a step-through passive avoidance task. Spatial working memory expressed as spontaneous alternations was tested in the Y-maze test. Coexposure to brain oligemia and STZ on the CNS produced significant impairment of long-term memory processes in mice. An additional exposure to Cd exacerbated the deficits of these processes. These results indicate that brain oligemia, Cd, and altered glucose metabolism may aggravate adverse effects on memory.