Abstract
This study investigated whether appetitive operant food reinforcement or free-feeding behavior in rats, food-restricted to 85% of body weight, was disrupted by exposures to 3 h of restraint stress or by 3 h of restraint plus water immersion stress (RWI). Rats were trained under a 3-cycle 10-min time-out-10-min time-in fixed-ratio 15 (FR15) schedule of food reinforcement. Free-feeding was measured in a 3-cycle 10-min food jar-out-l0-min food jar-in test conducted in the operant chambers. Three hours of restraint stress did not significantly affect response rate or food reinforcement in the operant FR15 task or in the free-feeding condition. In contrast, 3 h of RWI completely abolished operant food reinforcement and suppressed response rate, whereas free-feeding was significantly reduced but not abolished in food-restricted, hungry rats. We conclude that acute restraint stress in food-restricted, hungry rats does not affect their appetite or motor ability to lever-press for food nor did it affect their ability to feed in a free-feeding situation. In contrast, RWI stress may have induced a motor impairment, or some other aspect of motivation independent of hunger, that disrupted their performance in the operant FR15 task.
Original language | English (US) |
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Pages (from-to) | 827-830 |
Number of pages | 4 |
Journal | Physiology and Behavior |
Volume | 62 |
Issue number | 4 |
DOIs | |
State | Published - Oct 1997 |
Externally published | Yes |
Keywords
- Food intake
- Food restriction
- Free-feeding
- Operant behavior
- Rats
- Restraint
- Stress
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Behavioral Neuroscience