Social stress, immune functions and immuno-endocrine disorders in rodents and other animals

The link between stress, health and social factors has been the focus of many studies and the preferred subject of investigation of researchers from different disciplines. In particular rodent-based models modulating the social environment are becoming increasingly popular in the scientific literature as realistic models of human disease. A growing number of studies now prove that social factors in both early phases and adult life do have a widespread effect on neuroimmune functions. Accordingly, here we will provide an updated review of studies conducted prominently on laboratory rodents. However a number of studies have also been conducted in non-human primates, farm animals and birds. Results from different disciplines will be integrated to reach a clear conclusion: an allostatic overload, including neuroimmune abnormalities, is more likely to develop when unpredictable stressors of social nature, chronically induce physiological and behavioral adjustments that may 'wear and tear' the underlying physiological function.