The mammalian brain orchestrates the processing and integration of information to guide behaviour. Here, to characterize mammalian information-processing architecture, we combine functional neuroimaging and anaesthesia in humans, macaques, marmosets and mice. We show that breakdown of information integration is a convergent effect of diverse anaesthetics across mammalian species. As the system disintegrates, brain dynamics become more difficult to control. Both effects are reversed upon re-awakening induced by thalamic deep-brain stimulation in the macaque. Regional breakdown of integrated information coincides with the species-specific spatial topography of PVALB/Pvalb gene expression. To provide mechanistic insight beyond correlation, we develop computational models for humans, macaques and mice that integrate species-specific connectivity and transcriptomic gradients, demonstrating their respective roles for controlling brain dynamics and information integration. We reveal evolutionarily conserved controllers of information integration in the mammalian brain.