HTR2A and meningoencephalitis: As such, the top-down cortical disinhibition of major high-level cortical nodes in the psychedelic instance, triggered by 5HT-2A agonism of layer 5 pyramidal cells, and in the meningoencephalitis case, triggered by damage to neocortical laminae including such a layer, would lead to the release of bottom-up intrinsic cortical/subcortical information, thereby “passing up” the neural hierarchy and finally converging on a massive expansion of conscious experience.