ABSTRACT
Two different approaches can be used to study changes in gene expression between sleep and waking: in a targeted approach, one can examine the expression of a gene of interest; and in a systematic approach, one can examine changes in the expression of all mRNAs present in a given tissue. This chapter focuses on immediate early genes (IEGs) such as c-fos and detects changes in gene expression between sleep and waking. c-Fos encodes a transcription factor, Fos protein, that is induced by many extracellular stimuli. The use of antisense oligonucleotides targeted at Fos, as well as gene knockout approaches, has demonstrated that Fos can act as a transcription factor in vivo and produce functional and behavioral consequences. To study changes in the expression of Fos and other IEGs expression over the entire rat brain, a combination of radioactive in situ hybridization and immunocytochemistry is particularly useful.
