“…Brain structures outside of the limbic system that have lower levels of Npas4 expression include the cortex, striatum, olfactory bulb (OB), cerebellum and hypothalamus [ 5 , 6 , 21 , 47 , 48 ]. In the cortex, expression is highest in layers III and V and is present in the frontal, parietal and entorhinal cortices [ 5 , 6 , 21 , 22 ]. Some species-specific differences in Npas4 expression have been observed in the cerebellum; in the rat cerebellum, Npas4 expression is confined to the Purkinje cell layer, while in the mouse cerebellum, Npas4 is expressed in both the GCL and the Purkinje cell layer [ 5 , 6 ].…”