While the traditional systems of health have always had a holistic view of the interaction of different parts and organs of the body, Western science has long utilized reductionistic, atomistic, and fragmented approaches to physiology. This to a certain extent was necessary and appropriate in the development of science but when the limitations of this approach are not seen it leads to all kinds of incoherence.
Mainstream medicine has only postulated indirect and mediated mechanisms for a connection between the brain and the immune system. Now, a study in Nature titled:
Structural and functional features of central nervous system lymphatic vessels
has suggested that the brain has a direct connection to the immune system via meningeal lymphatic vessels.
From the abstract of the study:
One of the characteristics of the central nervous system is the lack of a classical lymphatic drainage system. Although it is now accepted that the central nervous system undergoes constant immune surveillance that takes place within the meningeal compartment the mechanisms governing the entrance and exit of immune cells from the central nervous system remain poorly understood. In searching for T-cell gateways into and out of the meninges, we discovered functional lymphatic vessels lining the dural sinuses. These structures express all of the molecular hallmarks of lymphatic endothelial cells, are able to carry both fluid and immune cells from the cerebrospinal fluid, and are connected to the deep cervical lymph nodes. The unique location of these vessels may have impeded their discovery to date, thereby contributing to the long-held concept of the absence of lymphatic vasculature in the central nervous system. The discovery of the central nervous system lymphatic system may call for a reassessment of basic assumptions in neuroimmunology and sheds new light on the aetiology of neuroinflammatory and neurodegenerative diseases associated with immune system dysfunction.