ABSTRACT
The major structures of the limbic in the brain, the hippocampus and the amygdala, are reviewed. The interaction of the various structures that comprise the limbic system is discussed. The limbic system is considered to be a neural network which can be mapped with monoclonal antibodies. Certain viral infections, such as Borna virus, have a predilection for the limbic system. Other limbic attributes are receptors for biogenic amines and neuropeptides, afferent and efferent neurons, and modulation by endogenous opioids, as well as interleukin-1, which has effects on slow-wave sleep, appetite, and fever. Mood and memory disorders have traditionally been associated with the limbic system, but recent discoveries in neurophysiology suggest that limbic dysregulation can produce illness behavior as well as dysfunction in many organ systems. Cells that secrete dopamine, norepinephrine, and serotonin are distributed throughout the brain stem and project to the limbic system. Limbic physiology is described as “medicine’s stepchild,” and disorders related to it have generally been labeled “psychiatric,” and not part of hard medical science. The concept of the limbic system as a neural regulator is a new one, but limbic dysfunction may produce the symptoms of chronic fatigue syndrome.
