Gene expression profiling in the amygdala: An approach to examine the molecular substrates of mammalian behavior

The molecular substrates of behavior have been difficult to assess because of the large number of messenger RNAs (mRNAs) expressed in a given brain re gion, the heterogeneous composition of the CNS, and the complexity of mamma lian behavior. To gain insight into the molecular components of behavior re quires an understanding of the anatomy associated with a specific behavior and the ability to examine multiple gene expression in discrete brain regio ns. Neuroanatomical and behavioral studies have demonstrated that the amygd aloid complex is an essential component of the neural pathways mediating be haviors, such as fear, anxiety, teaming, and memory. The amygdala is compos ed of several interconnected subnuclei and it is the modulation of informat ion, as it flows through these subnuclei, that underlies amygdala function. To examine the molecular components of the amygdala, we have combined the antisense RNA (aRNA) amplification procedure with microarray technology. Th is experimental approach permits the simultaneous detection and quantificat ion of numerous mRNAs in fixed tissue sections. Our initial experiment exam ines region-specific gene expression in naive mice in order to map the mole cular relationship between the subregions of the amygdala. This report prov ides a general over-view of the techniques used to examine regional gene ex pression, suggests future experiments, and describes a theoretical framewor k for examining the molecular analysis of behavior. (C) 2001 Elsevier Scien ce Inc. All rights reserved.