College
Rowan-Virtua School of Osteopathic Medicine
Keywords
social isolation, opioid receptor, affective behavior, cecum
IRB or IACUC Protocol Number
2020-1191
Date of Presentation
5-1-2025 12:00 AM
Poster Abstract
BACKGROUND
Psychological stress can induce gastrointestinal symptoms and exacerbate existing gastrointestinal disorders, indicating an interaction between the central and enteric nervous systems. Central nervous system activation of opioid receptors stimulates sympathetic outflow to the enteric nervous system, delaying motility and reducing gastrointestinal secretions, producing a similar clinical presentation to IBS.
HYPOTHESIS
We hypothesize that social isolation induces anxiety states, disrupting homeostatic noradrenergic activity in the brain and gut, leading to neurophysiological changes in the cecum characterized by altered expression of opioid receptors.
METHODS
Sprague-Dawley rats were housed in either group (control) or socially isolated conditions. Affective behavior was assessed using the Open Field, Elevated Plus Maze, Three-Chamber Social Isolation, and Defensive Shock Probe Burial tests. Cecal tissue was collected, cleaned, and processed for mRNA extraction and purification. RT-qPCR was used to quantify δ, κ, and μ opioid receptor expression.
RESULTS
Socially isolated rats exhibited decreased social behavior, increased neophobia, and more passive coping strategies compared to controls. μ opioid receptor (MOR) expression was significantly elevated in the socially isolated cohort compared to the control. δ and κ opioid receptor expression was undetectable by qPCR, suggesting low expression in the cecum and minimal involvement in gut opioid signaling.
CONCLUSIONS
Behavioral changes associated with social isolation stress correspond with increased MOR expression in the cecum. This upregulation may mediate stress-induced gastrointestinal dysfunction and represents a potential target for therapeutic intervention in stress-related GI disorders.
Disciplines
Behavioral Neurobiology | Behavior and Behavior Mechanisms | Cognitive Neuroscience | Digestive System | Disease Modeling | Gastroenterology | Medical Neurobiology | Medicine and Health Sciences | Nervous System | Pathological Conditions, Signs and Symptoms | Psychiatry
Included in
Behavioral Neurobiology Commons, Behavior and Behavior Mechanisms Commons, Cognitive Neuroscience Commons, Digestive System Commons, Disease Modeling Commons, Gastroenterology Commons, Medical Neurobiology Commons, Nervous System Commons, Pathological Conditions, Signs and Symptoms Commons, Psychiatry Commons
Effects of Social Isolation on Cecum Opioid Receptor Expression and Affective Behavior
BACKGROUND
Psychological stress can induce gastrointestinal symptoms and exacerbate existing gastrointestinal disorders, indicating an interaction between the central and enteric nervous systems. Central nervous system activation of opioid receptors stimulates sympathetic outflow to the enteric nervous system, delaying motility and reducing gastrointestinal secretions, producing a similar clinical presentation to IBS.
HYPOTHESIS
We hypothesize that social isolation induces anxiety states, disrupting homeostatic noradrenergic activity in the brain and gut, leading to neurophysiological changes in the cecum characterized by altered expression of opioid receptors.
METHODS
Sprague-Dawley rats were housed in either group (control) or socially isolated conditions. Affective behavior was assessed using the Open Field, Elevated Plus Maze, Three-Chamber Social Isolation, and Defensive Shock Probe Burial tests. Cecal tissue was collected, cleaned, and processed for mRNA extraction and purification. RT-qPCR was used to quantify δ, κ, and μ opioid receptor expression.
RESULTS
Socially isolated rats exhibited decreased social behavior, increased neophobia, and more passive coping strategies compared to controls. μ opioid receptor (MOR) expression was significantly elevated in the socially isolated cohort compared to the control. δ and κ opioid receptor expression was undetectable by qPCR, suggesting low expression in the cecum and minimal involvement in gut opioid signaling.
CONCLUSIONS
Behavioral changes associated with social isolation stress correspond with increased MOR expression in the cecum. This upregulation may mediate stress-induced gastrointestinal dysfunction and represents a potential target for therapeutic intervention in stress-related GI disorders.
