POSTISCHEMIC HYPERACTIVITY IN THE MONGOLIAN GERBIL CORRELATES WITH LOSS OF HIPPOCAMPAL-NEURONS

Gerbils show a postischemic increase in locomotor activity that correl ates to the extent of neuron loss in the hippocampal CA1 subfield. It has been suggested that this hyperactivity is predictive of neuron los s in the CA1. In this study the correlation between postischemic hyper activity and neuron loss in several hippocampal subfields was investig ated, and the theory that the hyperactivity is due to a reduced abilit y for spatial navigation was evaluated. Significant correlations were found between hyperactivity and neuron loss in several hippocampal sub fields; the correlation was stronger for the CA3 than for the CA1 subf ield, suggesting that postischemic hyperactivity can be used as a pred ictor of neuron loss in the CA3 rather than in the CA1. From observati ons of the pattern of hyperactivity within the test arenas and during the test period, this study challenges the spatial mapping theory of p ostischemic hyperactivity.