Consciousness as a Conversation
In summary, local properties of the cortex and its satellite structures mediate the specific content of consciousness, whereas global properties are critical for sustaining consciousness per se. For a coherent coalition of neurons to assemble at all— and for awareness to emerge— the cortico-thalamic complex needs to be suffused with neurotransmitters, chemicals released by the long and winding tentacles of neurons in the deeper and older parts of the brain. Both local and global aspects are critical for consciousness.
Koch, Christof. Consciousness: Confessions of a Romantic Reductionist (MIT Press) (p. 74). The MIT Press. Kindle Edition.