Erythropoietin improves spatial delayed alternation in a T-maze in fimbria-fornix transected rats.

Systemically administered human recombinant erythropoietin (EPO) may have the potential to reduce the cognitive and behavioural symptoms of a mechanical brain injury. In a series of studies we address this possibility. We have previously found that EPO given to fimbria-fornix transected rats at the moment of injury is able substantially to improve the posttraumatic acquisition of allocentric place learning tasks administered in a water maze as well as in an 8-arm radial maze. It is, however, essential to evaluate this clinically important ability of EPO within other cognitive domains, as well. Consequently, we presently studied the effects of similarly administered EPO in fimbria-fornix transected and control operated rats, respectively--evaluating the posttraumatic behavioural/cognitive abilities in a spatial delayed alternation task performed in a T-maze. Administration of EPO to the hippocampally injured rats was associated with a substantial reduction of the lesion-associated behavioural impairment--while such an impairment was clearly seen in the saline injected fimbria-fornix transected group. In contrast, EPO had no detectable effect on the task acquisition of non-lesioned animals. The results of the present study confirm our previous demonstrations that EPO is able to reduce or eliminate the behavioural/cognitive consequences of mechanical injury to the hippocampus--and emphasize that this ability is present across a broader spectrum of cognitive domains.