Decreased NGFI-A gene expression in the hippocampus of cognitively impaired aged rats

Hippocampal NGFI-A gene expression is increased following the induction of long-term potentiation, a form of activity-dependent synaptic plasticity that has been implicated in learning. In this study, we show a positive correlation between spatial learning and the constitutive expression of NGFI-A mRNA, selectively in CA1 pyramidal neurons. NGFI-A mRNA expression decreased with age in CA1, CA2 and neocortex. Long-term amitriptyline treatment, which improved spatial learning in young rats, had no significant effects on NGFI-A mRNA levels. Whether hippocampal NGFI-A plays a direct role in the mechanism of learning and memory remains to be determined.