Allostasis, maintenance of stability through changes in an organism, is critically dependent on bi-directional communication between the neuroendocrine and immune systems. The immune and neuroendocrine systems share mediators and their receptors, and thus immune responses are reflected in neuroendocrine changes while, in turn, hormones and neuropeptides modulate immune functions. Disturbance of allostasis may have negative influence on the health status and welfare of humans/animals.
There is a large body of evidence that endogenous opioids produced by activated neuroendocrine system exert a variety of effects on immune performance. Opioids can affect the immune response either directly via opioid receptors localised on leukocytes, or indirectly via activation of stress axis and sympathethic nervous system. Opioids and receptors have been identified in fish and their evolutionary relationship with mammalian factors and functions supports their essential role in neuroendocrine and immune responses. Understanding the physiological significance of this communication will allow developing efficient strategies for health control in aquaculture. This project aims to undertake a joint effort within three laboratories to perform an interdisciplinary study into the role of opioids and opioid receptors in farmed fish. Joining forces of the expert knowledge in fish immunology (Wageningen), neuroendocrinology (Nijmegen), together with the inflammation model developed in Poland will guarantee optimal conditions. The different types of opioid receptors are characterised and influence of opiates on innate immune response and on classical stress axis are established.