Although immunology and neuroscience are seemingly two different and separate disciplines, recent findings have blurred the boundaries between them. For example, a cytokine that was previously clearly defined in the immune system, interleukin-1 (IL-1), has been found to have the function of activating a seemingly irrelevant population of hypothalamic neurons (Kelley and McCusker, 2014). Such interactions can cause the generation of glucocorticoids by the adrenal gland, a hormone that is involved in the regulation of the immune functions.
In another example, lymphoid cells have been found to synthesize the neurotransmitter acetylcholine, a component in the nervous system (Kelley and McCusker, 2014). The neurotransmitter acetylcholine in turn can inhibit the production of tumor necrosis factor (TNF), a cytokine in the immune system. For the immune systems, at least 35 cytokines and their receptors have been formally defined. For the nervous system, more than 60 classical neurotransmitters and at least 50 neuroactive peptides have been well defined (Kelley and McCusker, 2014).
It would be very interesting to identify the interactions among these cytokines and cytokine receptors from the immune system, and the neurotransmitters from the nervous system. An integrative approach is needed to combine immunology and neuroscience to have a holistic view of the interactions between the nervous system and the immune system.
Kelley KW, McCusker RH. Getting nervous about immunity. Semin Immunol. 2014 Feb 17. pii: S1044-5323(14)00012-8. doi: 10.1016/j.smim.2014.01.011.