The pineal and thymus gland interaction on the immune system stimulation, through the melatonin hormone effect

A challenging topic in undergraduate physiology courses is the complex interaction between the vertebrate endocrine system and the immune system. There are relatively few established and accessible laboratory exercises available to instructors to help their students gain a working understanding of these interactions. The present laboratory module was developed to show students how glucocorticoid receptor activity can be pharmacologically modulated in Xenopus laevis tadpoles and the resulting effects on thymus gland size visualized and quantified in vivo. After treating young tadpoles with a cortisol receptor agonist (dexamethasone) for 1 wk, students can easily visualize the suppressive effects of glucocorticoids on the intact thymus gland, which shrinks dramatically in size in response to this steroid hormone analog. However, the suppressive effect of dexamethasone is nullified in the presence of the glucocorticoid receptor antagonist RU-486, which powerfully illustrates the specific effects of glucocorticoid receptor inhibition on the immune system. Image analysis and statistics software are used to quantify the effects of glucocorticoid modulation on thymus size.

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The Thymus Gland

Neonatal Network The Journal of Neonatal Nursing ◽

10.1891/0730-0832.20.8.7 ◽

2001 ◽

Vol 20 (8) ◽

pp. 7-13 ◽

Cited By ~ 3

Author(s):

Debbie Fraser Askin ◽

Sandra Young

Keyword(s):

Immune System ◽

Digeorge Syndrome ◽

Modern Science ◽

Lymphoid Organ ◽

Thymus Gland ◽

Fetal Life

This article reviews the embryology, physiology, and pathophysiology of the thymus. The anatomy of this lymphoid organ, the significance of the presence or absence of the thymus radiographically, and the role of the thymus in immunity are also reviewed. Finally, the pathologic presentation of thymic hypoplasia (DiGeorge syndrome) is discussed. Despite advances in modern science, little was known about the thymus, one of the body’s key organs in the immune system, until 1961, when Dr. Jacques Miller performed thymectomies in mice. Then it became evident that the thymus played a key role in the body’s defense against infection. Since that time, researchers have continued to examine the role of the thymus from fetal life through adulthood.

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Parasite Evolution and the Immune System

Allergy & Clinical Immunology International - Journal of the World Allergy Organization ◽

10.1027/0838-1925.17.6.229 ◽

2005 ◽

Vol 17 (06) ◽

pp. 229-236

Author(s):

Kathleen Barnes

Keyword(s):

Immune System ◽

Parasite Evolution

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Learned Placebo Effects in the Immune System

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000184 ◽

2014 ◽

Vol 222 (3) ◽

pp. 148-153 ◽

Cited By ~ 2

Author(s):

Sabine Vits ◽

Manfred Schedlowski

Keyword(s):

Nervous System ◽

Immune System ◽

Associative Learning ◽

Placebo Response ◽

Immunosuppressive Drug ◽

Immune Functions ◽

Placebo Effects ◽

New Therapeutic Approaches ◽

Biological Variables ◽

Experimental Approaches

Associative learning processes are one of the major neuropsychological mechanisms steering the placebo response in different physiological systems and end organ functions. Learned placebo effects on immune functions are based on the bidirectional communication between the central nervous system (CNS) and the peripheral immune system. Based on this “hardware,” experimental evidence in animals and humans showed that humoral and cellular immune functions can be affected by behavioral conditioning processes. We will first highlight and summarize data documenting the variety of experimental approaches conditioning protocols employed, affecting different immunological functions by associative learning. Taking a well-established paradigm employing a conditioned taste aversion model in rats with the immunosuppressive drug cyclosporine A (CsA) as an unconditioned stimulus (US) as an example, we will then summarize the efferent and afferent communication pathways as well as central processes activated during a learned immunosuppression. In addition, the potential clinical relevance of learned placebo effects on the outcome of immune-related diseases has been demonstrated in a number of different clinical conditions in rodents. More importantly, the learned immunosuppression is not restricted to experimental animals but can be also induced in humans. These data so far show that (i) behavioral conditioned immunosuppression is not limited to a single event but can be reproduced over time, (ii) immunosuppression cannot be induced by mere expectation, (iii) psychological and biological variables can be identified as predictors for this learned immunosuppression. Together with experimental approaches employing a placebo-controlled dose reduction these data provide a basis for new therapeutic approaches to the treatment of diseases where a suppression of immune functions is required via modulation of nervous system-immune system communication by learned placebo effects.

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