I'm reading this paper, which discusses how Serotonin may be involved in motor functions of mammals: 5-HT and motor control: a hypothesis .
The paper includes the following diagram of the Dorsal Raphe Nuclei (DRN) firing pattern in a walking cat, and cat on a tredmill. Each step is associated with a distinct firing pattern. I'm wandering if the DRN firing pattern, in humans, changes in a similar way in response to voluntary breathing?
After searching wikipedia, I found a line that says:
REM sleep is turned on by acetylcholine secretion and is inhibited by neurons that secrete serotonin. (Psysiology of sleep stages)
I'm interested in dreaming, and at times have practiced entering dreams consciously, from the waking state after laying in bed for a long time. One of the obstacles to entring a dream was seizing control of breathing and starting to breathe voluntarily. This prevented me from entering dreams on a number of occasions, and appears to support the idea that voluntary breathing would affect the DRN. But I'm looking for a more scientifically-validated answer.
Thank you for your input!