Expression of c-fos and other genes encoding transcription factors in long-term potentiation

The genes encoding transcription factors are known to be induced in many different biological phenomena of transition from one long-lasting state of cell functioning to another. It is widely believed that transcription factors control this transition by regulating the expression of other genes. Recently, several reports on gene expression after the induction of long-term potentiation (LTP) have been published. In particular, the c-fos nuclear protooncogene, encoding the Fos transcription factor, has been extensively investigated. However, the results of those studies were seemingly contradictory. The present commentary reviews available data in an attempt to resolve the apparent contradictions, showing that long-lasting LTP (i.e., lasting longer than a few hours) may involve c-fos expression, while shorter LTP may not.