Yesterday I went to a lecture by Dr. Jim Hopkins, a former editor of MIND. The lecture was entitled Psychoanalysis, Dreams and Biosemantic Representation. I didn't expect my muse to be in the room, but Jim began the lecture by informing us that dopamine neurons resume normal, daytime-like activity during dreaming. Shock. Apparently dopamine neurons resume normal activity about once every hour during sleep, and this coincides with dreaming and the interruption of slow wave sleep. I've got no articles on it yet but it makes perfect sense: dopamine flow returns to the cortex, the slow rhythm pumping out of the thalamus is interrupted and the neruonal growth we call consciousness resumes. But it's a consciousness that is disconnected from sensory reality; unhinged; unreal; pure memory and imagination forming the dopaminergic narrative. Dreaming then, is just like waking life, a constant focus on that which generates most dopamine (see image below); but unrestrained and dissociated from the physical environment it lets us recombine and reevaluate our memories and aspirations. Jim tried to use the dopamine-reward connection to argue for the Freudian intepretation of dreams a wish fulfilment, but though dreams may share with waking-life a constant SEEKING, maybe they are better thought of simply as exploration: the blind, sleeping brain exploring itself, seeking the dopamine of fantasy and nightmare alike. Once a dopaminergic source has been found, the brain explores it, much like a day-dream, and a narrative is created. Dreaming is the cortical elaboration of a dopaminergic trace, in the chemical environment of a sleeping body, untethered by sensation, movement and the environment.
A month ago I wrote a few lines about endogenous activation of dopamine neurons. Here's an elaborated diagram. The frontal lobes are driven (SEEKING) to activate dopamine neurons, both directly and via their connections to the rest of the cortex. They can also use their connections to the motor cortex to make the eyes follow an attractive price, a strange animal or a threatening shadow, all of which would supply them with dopamine via other brain regions. They can go further into abstraction, plan ahead, and use their motor connections to orchestrate complex behaviors that eventually place the body in a situation where any (or all) of the other brain structures with direct connections to the dopamine neurons are stimulated (consider the things in red). This is will. But in dreaming, the frontal lobes have no access to the world, and must explore the dream using only their connections to the rest of the sleeping brain.