Noradrenergic Modulation of Light-Driven Egr-1 Expression in the Adult Visual Cortex.

Noradrenaline has been shown to modulate sensory driven responses in the primary visual cortex (V1) of a number of vertebrate species. Moreover, this neurotransmitter has been postulated to bridge neuronal activation to genomic responses in order to instruct cells in long-lasting changes in neuronal performance. Here we show that local noradrenergic receptor activation in V1 is required for experience-regulated gene expression in the mouse V1. More specifically, we demonstrate that noradrenaline used locally within V1 mediates the light-driven gene expression of egr-1, an immediate early gene implicated as a mediator of neuronal plasticity. Visually-driven egr-1 expression largely depends on the α-adrenergic receptor subtype, with a lesser involvement of the β-subtype. Our findings suggest that noradrenergic transmission regulates plasticity associated gene expression in V1 of awake mice and is well positioned to broadly integrate experience-dependent changes at the cell's membrane and the genomic machinery in neurons.