CREB1 and infection: No control groups showed any increase in long-term memory performance to massed training: rats microinjected with a control substance, rats microinjected with a mutated inactive form of the CREB gene, rats microinjected with a Lac-Z gene with no learning and memory effects, rats whose microinjections had missed or whose infections had extended beyond the amygdala basolateral nucleus, and rats microinjected with the CREB gene directly into the caudate nucleus.