COMBINATORIAL EXPRESSION OF IMMEDIATE-EARLY GENES IN SINGLE NEURONS

To address the question how relatively small numbers of immediate earl y gene (IEG) could specifically couple a wide range of stimulus-respon se cascades, we examined the possibility that IEG could be expressed h eterogeneously in individual neurons. Analysis of multiple IEG in sing le neurons revealed that many individual DRG neurons express several I EGs. The combinatorial expression of IEGs by individual DRG displays s ubstantial heterogeneity. Analysis of mRNA species encoding AP-1 compo sition in single cells also revealed coordinated change of mRNAs codin g for AP-1 factors after membrane depolarization. Our results indicate that differential expression of IEG in individual cells, and the poss ible interaction among them may represent a mechanism by which the spe cificity in stimulation-response coupling may be achieved by IEGs.