Visualization of functionally activated circuitry in the brain

Abstract

We have used a transgenic approach to visualize functionally activated neurons and their projections. The transgenic mice contain a tau-lacZ fusion gene regulated by the promoter for c-fos, an immediate early gene that is rapidly induced in neurons after functional stimulation. Constitutive expression of β-galactosidase (β-gal), the lacZ product, was low and in accord with previous reports of c-fos expression. However, expression of β-gal in positive neurons was clearly in cell bodies, axons, and dendrites. Treatment of the mice with kainic acid, a strong inducer of c-fos expression, resulted in high induction of β-gal. β-gal was induced in the same defined populations of neurons in the brai..