CREB and neuronal selection for memory trace

Jieun Kim,Jin-Hee Han,Hyung-Su Kim,Jeong-Tae Kwon

doi:10.3389/fncir.2013.00044

Abstract

Despite considerable progress over the past several decades, our understanding of the mechanisms underlying memory encoding, storage, and expression in a complex neural network are far from complete. In particular, how some neurons rather than others are selectively engaged to encode memory remains largely unknown. Using virus-mediated gene delivery into a small subset of neurons in a given network, molecular imaging of neuronal activity, pharmacological perturbation of specific neurons' activity and animal behavior assays, recent studies have begun to provide insight into molecular and cellular mechanisms responsible for the selection of neurons for inclusion into a memory trace. Here, we focus on a review of recent findings supporting the hypothesis that the level of the transcription factor CREB (cAMP/Ca2+-response element binding protein) is a key factor governing which neurons are recruited to a given memory trace. These recent findings open a new perspective on memory trace at the neural circuit level and also raise many important questions. Future studies employing more advanced neurobiological techniques for targeting defined populations of neurons and manipulating their activity in time and space in a complex neural network will give answers to these newly emerging questions and extend our understanding of the neurobiological basis of the memory trace.

Highlights

Despite considerable progress over the past several decades, our understanding of the mechanisms underlying memory encoding, storage, and expression in a complex neural network are far from complete
Because the brain is a complex structure formed by connections of billions of nerve cells, the memory trace, which is the physical substrate of memory in the brain, must be understood at the neural circuit level (Lashley, 1950; McGaugh, 1972; Schacter, 2001; Thompson, 2005; Neves et al, 2008; Mayford et al, 2012)
How are particular neurons recruited into a given memory trace? Are there predetermined stereotyped neurons for a specific memory? Alternatively, are particular neurons in a given neural network actively selected by some mechanism(s) at the time of learning? If a specific set of neurons is selected for encoding of memory during learning, are the selected neurons essential for the subsequent expression of that memory?

Summary

Introduction

Despite considerable progress over the past several decades, our understanding of the mechanisms underlying memory encoding, storage, and expression in a complex neural network are far from complete. Recent studies have begun to address some of these questions, providing evidence suggesting that the transcription factor CREB governs the selection of neurons for inclusion into a fear memory trace.

Results

Conclusion