New player in memory persistence: Retrosplenial cortex

KATCHE C; DORMAN G; KRAMAR C; GONZALEZ C; SLIPCZUK LN; IZQUIERDO I; CAMMAROTA M; MEDINA JH

Congreso; Society for Neuroscience; 2011

A prevailing view of the modern science of memory is that memories are initially fragile but become more stable with time. While persistence is a key characteristic of memory storage, its mechanisms are scarcely characterized. To understand the processes that underlie memory, we must comprehend how is it that memory traces persist despite the short-lived nature and rapid turnover of their molecular substrates. Although the hippocampus is crucial in the formation of new declarative memories, other brain regions probably mediate permanent storage of remote memories. For this reason, we decided to investigate the role of retrosplenial cortex and the molecular mechanisms involved in memory processing. In this work, we show that long-lasting but not short-lived inhibitory avoidance (IA) long-term memory depends on a delayed expression of c-Fos in the retrosplenial cortex. Moreover, inhibition of transcription in the retrosplenial cortex impairs memory formation around and a few hours later after IA training. In addition, translation is required in the retrosplenial cortex around training for memory formation and, late after training for memory persistence. These findings indicate that delayed phases of transcription and translation are essential for maintenance of a fear-motivated memory trace. Our results support the hypothesis that recurrent rounds of consolidation-like events take place late after learning in the dorsal retrosplenial cortex to maintain memories.