Inducing gene expression in barrel cortex--focus on immediate early genes.

Using only their vibrissae, rats and mice are able to recognize and differentiate surfaces not distinguishable by primates using their fingertips. It has been shown that sensory stimulation elicits the expression of immediate-early genes (IEG), e.g., c-fos and zif268, in the sensory cortex of rats and mice. Though most of these findings come from visual system, mice and rats rely more on their vibrissal system which also offers many advantages for designing precise and precisely controlled experiments. In this review, new models for the selective and simple stimulation of vibrissae are presented and discussed. The data demonstrating IEG expression in the vibrissal system is also reviewed.