Involvement ofc-Fos and CREB in cortical and subcortical brain regions during acquisition and recall of socially transmitted food preferences
Description
The medial temporal lobe has been studied extensively over the last half century in attempts to elucidate the systems and mechanisms underlying declarative memory formation. It is now known that the hippocampus is essential to the establishment of long-term declarative memory but the cellular mechanisms involved are not as well understood. The social transmission of food preferences is a nonspatial, hippocampus-dependent behavioral paradigm that is well suited to the study the cellular mechanisms of declarative memory. The transcription factors c-Fos and CREB are known markers of neuronal activation and are reportedly necessary for long-term memory formation. The present series of experiments was designed to investigate the mechanisms and systems involved in nonspatial hippocampus-dependent memory. The results of Experiments 1 and 2 established that c-Fos expression and phosphorylation of CREB occur in the hippocampus after both acquisition and recall of a socially transmitted food preference. Subsequent experiments examined the extent to which multiple brain regions are involved during acquisition and recall of a socially transmitted food preference and whether or not c-Fos is necessary for long-term memory formation. The results of Experiment 3 provide further evidence that multiple memory systems may operate in temporal sequence during memory consolidation. Experiment 4 established the time-window of effectiveness for suppression of learning-induced expression of c-Fos using antisense administration. Experiment 5 established a causal relationship between c-fos expression and long-term memory; the infusion of antisense to c-fos impairs long-term memory, but leaves short-term intact. Two main conclusions emerge from these experiments: (1) There are time dependent roles of various brain structures in the acquisition and recall of food preferences and (2) c-Fos is not only correlated with neuronal activation, but is required for the establishment of long-term memory for a socially transmitted food preference