Related Experiment Video
Updated: Sep 8, 2025
06:43
Increased Recovery Time and Decreased LPS Administration to Study the Vagus Nerve Stimulation Mechanisms in Limited Inflammatory Responses
Published on: March 29, 2017
10.0K
Comparing two anti-inflammatory reflexes: Splanchnic and hypothalamic-pituitary-adrenal
Michael McKinley1, Song T Yao2, Davide Martelli3
1The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Australia; Department of Anatomy and Physiology, The University of Melbourne, Australia.
Brain, Behavior, and Immunity
|September 5, 2025
Summary
The autonomic nervous system and adrenal axis initiate anti-inflammatory reflexes. Both suppress TNF, but have opposing effects on IL-10, revealing their roles in cytokine balance.
Area of Science:
- Neuroimmunology
- Endocrinology
- Inflammation Research
Background:
- The autonomic nervous system and hypothalamic-pituitary-adrenal (HPA) axis are key regulators of the immune response.
- Systemic immune challenges trigger anti-inflammatory reflexes mediated by both systems.
- Understanding the interplay between these two systems is crucial for managing inflammatory conditions.
Purpose of the Study:
- To compare the in vivo anti-inflammatory roles of the autonomic nervous system and the HPA axis.
- To elucidate the distinct contributions of these pathways to cytokine regulation (TNF and IL-10) during immune challenge.
- To investigate the independent and combined effects of disrupting these reflexes on inflammatory markers.
Main Methods:
- Experiments were conducted in male urethane-anesthetized rats.
- Key interventions included bilateral splanchnic nerve section and bilateral adrenalectomy.
- Systemic immune challenge was induced using intravenous lipopolysaccharide (LPS).
- Plasma levels of tumor necrosis factor α (TNF) and interleukin 10 (IL-10) were measured.
Main Results:
- Disabling the autonomic reflex (splanchnic nerve section) increased TNF and decreased IL-10 responses to LPS.
- Adrenalectomy (removing catecholamines and glucocorticoids) increased TNF but not IL-10 responses.
- Both the autonomic reflex and adrenal glucocorticoids independently suppress TNF production.
- Simultaneous disruption of both pathways led to an additive increase in TNF levels.
- Glucocorticoids were found to actively suppress IL-10, while catecholamines may enhance it.
Conclusions:
- Two potent, independent anti-inflammatory reflexes (autonomic and HPA axis) suppress TNF during immune challenge.
- These reflexes exert opposing regulatory control over IL-10, influencing overall cytokine balance.
- The findings highlight the complex, dual role of these systems in modulating inflammatory and anti-inflammatory cytokine profiles.
Related Concept Videos
01:37Hypothalamic-Pituitary Axis
61.6K
The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor.
61.6K
01:24Physiological Foundation of Stress
156
Stress triggers a coordinated physiological response involving the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. This dual activation ensures that the body is prepared for both immediate and prolonged stress management. The process begins with the perception of a stressor. This initial phase activates the SNS, leading to the rapid release of adrenaline (epinephrine) from the adrenal glands.
Role of the Sympathetic Nervous System
Adrenaline triggers the...
Role of the Sympathetic Nervous System
Adrenaline triggers the...
156
01:27Sympathetic Pathways: Collateral Ganglia and Adrenal Medulla
1.5K
The sympathetic pathways of the collateral ganglia and adrenal medulla serve unique but interconnected roles in the sympathetic response.
Collateral Ganglia
Sympathetic preganglionic axons reach the collateral ganglia along the route of splanchnic nerves. These nerves bypass the sympathetic trunk and communicate with sympathetic postganglionic neurons housed in the prevertebral ganglia. These ganglia supply the organs of the abdominopelvic cavity.
The greater splanchnic nerve, formed by the...
Collateral Ganglia
Sympathetic preganglionic axons reach the collateral ganglia along the route of splanchnic nerves. These nerves bypass the sympathetic trunk and communicate with sympathetic postganglionic neurons housed in the prevertebral ganglia. These ganglia supply the organs of the abdominopelvic cavity.
The greater splanchnic nerve, formed by the...
1.5K
01:22Autonomic Nervous System
9.5K
The autonomic nervous system (ANS) is a critical component of the peripheral nervous system, primarily responsible for regulating involuntary bodily functions and maintaining homeostasis. It functions in tandem with the central nervous system (CNS) to seamlessly coordinate various physiological processes without the need for conscious control.
The ANS comprises two main divisions: the sympathetic and parasympathetic divisions. These divisions function antagonistically to maintain a dynamic...
The ANS comprises two main divisions: the sympathetic and parasympathetic divisions. These divisions function antagonistically to maintain a dynamic...
9.5K
01:21Stress Response System
197
The stress response system, also known as the fight-or-flight response, is the body's automatic physiological reaction to perceived threats. Hans Selye introduced the concept of General Adaptation Syndrome (GAS) to describe the predictable pattern of changes that occur in response to stress. GAS consists of three sequential stages: alarm, resistance, and exhaustion. This model helps explain how chronic stress can contribute to health problems.
Alarm stage
In the alarm stage, the body's...
Alarm stage
In the alarm stage, the body's...
197
01:28Inflammatory Response
6.9K
An inflammatory response is a localized, nonspecific immune reaction that occurs when a tissue is injured. It is characterized by redness, swelling, heat, and pain, which are commonly called the cardinal signs and symptoms of inflammation. Inflammation can sometimes result in a loss of function.
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...
6.9K