Related Experiment Video
Updated: Jul 1, 2026
Moderate Prenatal Alcohol Exposure and Quantification of Social Behavior in Adult Rats
Published on: December 14, 2014
The progesterone receptor and parental behavior in juvenile rats
Benjamin C Nephew1, Dennis F Lovelock, Robert S Bridges
1Tufts University Cummings, School of Veterinary Medicine, North Grafton, MA 01536, USA. bcnephew@aol.com
Insights
Juvenile rats show strong parental behavior, but progesterone does not inhibit this response. This suggests different biological mechanisms control parental care in juveniles versus adults.
Area of Science:
- Neuroscience
- Behavioral Endocrinology
- Animal Behavior
Background:
- Juvenile rats (18-25 days) display heightened parental care compared to adults.
- Progesterone is known to inhibit parental care in adult rats and mice.
Purpose of the Study:
- To investigate the role of progesterone in the parental behavior of juvenile rats.
- To test the hypothesis that progesterone inhibits juvenile parental responsiveness as they age.
Main Methods:
- Male and female juvenile rats were implanted with progesterone, the antagonist RU486, or control implants.
- Parental behavior was assessed in all treatment groups.
Main Results:
- Neither RU486 nor progesterone administration significantly affected parental behavior latencies in juvenile rats.
- No significant differences in parental behavior were observed between treatment groups.
Conclusions:
- Progesterone does not appear to play an inhibitory role in juvenile rat parental behavior.
- The mechanisms governing juvenile and adult parental behavior are distinct.
Abstract:
Juvenile rats exhibit enhanced parental behavior responses to foster pups from 18 to 25 days of age, compared to virgin adults. Previous studies in adult rats and mice suggest that progesterone can inhibit the display of parental care towards offspring. The present study investigated the role of progesterone in juvenile rat parental behavior. It is hypothesized that the decrease in parental responsiveness as juveniles age is due a progesterone-dependent inhibitory mechanism. Groups of male and female juveniles were subcutaneously implanted with the progesterone antagonist RU486, progesterone, or control implants. All juveniles were then tested for parental behaviors. No significant effects of either RU486 or progesterone treatments on parental behavior latencies were detected in male or female juveniles. The current data support the concept that the mechanisms controlling juvenile and adult parental behavior are divergent. Progesterone does not seem to be involved in the display of parental behavior in juvenile rats.
