Background:
According to the views of psychoneuroendocrinoimmunology, many interactions
exist between nervous, endocrine and immune system the purpose of which is to achieve adaptive
measures restoring an internal equilibrium (homeostasis) following stress conditions. The center where
these interactions converge is the hypothalamus. This is a center of the autonomic nervous system that
controls the visceral systems, including the immune system, through both the nervous and neuroendocrine
mechanisms. The nervous mechanisms are based on nervous circuits that bidirectionally connect
hypothalamic neurons and neurons of the sympathetic and parasympathetic system; the neuroendocrine
mechanisms are based on the release by neurosecretory hypothalamic neurons of hormones that target
the endocrine cells and on the feedback effects of the hormones secreted by these endocrine cells on
the same hypothalamic neurons. Moreover, the hypothalamus is an important subcortical center of the
limbic system that controls through nervous and neuroendocrine mechanisms the areas of the cerebral
cortex where the psychic functions controlling mood, emotions, anxiety and instinctive behaviors take
place. Accordingly, various studies conducted in the last decades have indicated that hypothalamic
diseases may be associated with immune and/or psychic disorders.
Objective:
Various researches have reported that the hypothalamus is controlled by the cerebellum
through a feedback nervous circuit, namely the hypothalamocerebellar circuit, which bi-directionally
connects regions of the hypothalamus, including the immunoregulatory ones, and related regions of the
cerebellum. An objective of the present review was to analyze the anatomical bases of the nervous and
neuroendocrine mechanisms for the control of the immune system and, in particular, of the interaction
between hypothalamus and cerebellum to achieve the immunoregulatory function.
Conclusion:
Since the hypothalamus represents the link through which the immune functions may
influence the psychic functions and vice versa, the cerebellum, controlling several regions of the hypothalamus,
could be considered as a primary player in the regulation of the multiple functional interactions
postulated by psychoneuroendocrinoimmunology.
The Role of Neuropeptide Y in the Nucleus Accumbens