Stress-induced eating in rats

Area of Science:

• Neuroscience
• Physiology
• Behavioral Science

Background:

• The tail pinch (TP) test is a well-established method for inducing feeding behavior in rodents.
• Understanding the physiological and neural mechanisms underlying feeding is crucial for addressing obesity and eating disorders.

Purpose of the Study:

• To investigate the utility of the tail pinch (TP) as a model for studying ingestive behavior and its regulation.
• To explore the role of satiety signals and hormonal factors in TP-induced feeding.

Main Methods:

• Rats were subjected to mild tail pinch (TP) to elicit ingestive behavior.
• Food intake, gnawing, and licking behaviors were quantified.
• Circadian rhythms, blood glucose levels, and the effects of satiety signals (stomach distension, glucose) were examined.
• Parenteral administration of glucagon, cholecystokinin-octapeptide, bombesin, and thyrotropin-releasing hormone was used.
• Chronic TP was implemented to assess long-term effects on spontaneous food intake.

Main Results:

• Mild TP induced ingestive behavior in 72% of rats, with 20% showing gnawing and 8% licking.
• Food intake peaked at 1 minute, and a circadian rhythm was observed, with peak ingestion at 24 hours.
• TP caused a transient increase in blood glucose.
• Stomach distension and glucose administration suppressed feeding.
• Administered hormones (glucagon, CCK, bombesin, TRH) suppressed TP-induced feeding.
• Chronic TP led to a decrease in spontaneous food intake.

Conclusions:

• The tail pinch (TP) test is a robust and versatile model for studying eating behavior, correlating with starvation-induced eating.
• TP allows for the study of satiety signals and anorectic drug effects without the confounding factors of food deprivation or nausea.
• This model facilitates research into the neurobiological underpinnings of appetite and satiety.