Dreams and Dreaming State in the Brain

An important aspect in the explanation of dreaming is an understanding of the portions of the brain, which work together to create and terminate dreams and the dreaming state (i.e. REM sleep). A variety of nuclei and brain regions are involved in the initial production of the REM state, including the amygdala, hippocampus, right temporal lobe, and especially the brainstem nuclei located in the lateral and medial pons(1). REM sleep begins with signals from the base of the brain called the pons. The pons are associated with ritcular activity, and send signals to the region of the brain called the thalamus, which intern passes them along to the cerebral cortex for interpretation. While the pons are sending signal to the thalamus, they are also sending signals to the spinal chord, which shut off motor neurons making it impossible for the body to move during sleep and dreaming(3) . Similarly, cerebral blood flow increases in the right temporal and parietal regions during REM. These stages are followed by abnormal and enhanced activity in the right temporal and temporal-occippital area, which causes an increase in dreaming and REM sleep for an uncharacteristically long period of time. The brainstem is the most important actor in dream production, for it controls the steady and specific oscillations between REM and nonREM sleep, the same system that controls body and mind activation in waking periods(4). Overall, dreaming and REM sleep are associated with high levels of activity in the brainstem, occipital lobe, and other nuclei(1).