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Updated: Apr 24, 2026
A Conflict Model of Reward-seeking Behavior in Male Rats
Published on: February 20, 2019
How sexual behavior in male rats is inhibited by repeated maternal separation during early postnatal development
M R Ferraz1, L N Santos2, J S Guimarães1
1Departamento de Farmacologia e Psicobiologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
Insights
Maternal separation in early life causes long-term behavioral issues in male rats, including reduced sexual behavior and increased anxiety and depression. Early postnatal stress impacts adult male rat behavior.
Area of Science:
- Neuroscience
- Behavioral Science
- Endocrinology
Background:
- Perinatal stress can significantly alter hormone regulation and behavior.
- Maternal separation is a known risk factor associated with depressive illness.
Purpose of the Study:
- To investigate the effects of maternal separation on motivational and consummatory measures of sexual behavior in male rats.
- To examine the impact of maternal separation on the temporal patterning of sexual behavior.
- To assess anxiety and depressive-like behaviors in maternally separated rats.
Main Methods:
- Male rat litters were separated from mothers for 180 minutes daily from postnatal day 1 to 21.
- Sexual behavior was assessed at 90 days of age using standard parameters and mount bout analysis.
- Anxiety and depressive behaviors were evaluated using the forced swim test, open field test, and elevated plus maze test.
Main Results:
- Maternal separation increased latencies to mount, intromission, and ejaculation.
- Separated rats exhibited decreased intromission ratios and altered temporal patterning of sexual behavior.
- Maternally separated rats displayed increased depressive and anxiety-like behaviors.
Conclusions:
- Perinatal stress induced by maternal separation leads to lasting changes in sexual behavior in adult male rats.
- Early postnatal stress results in persistent depressive and anxiety-like behaviors into adulthood.
- Maternal separation serves as a model for understanding the long-term behavioral consequences of early life stress.
Abstract:
Perinatal stress can have lasting effects on hormone regulation and behavior. An association between maternal separation and depressive illness is well established. The present study was undertaken to investigate the effects of maternal separation on both motivational and consummatory measures and on the temporal patterning of sexual behavior in male rats. Litters were separated from their mothers for 180 min per day from P1 to P21 (birth=P0) and placed in an isolated box. Control litters remained with their mothers and were not disturbed. At 90 days of age, the sexual behavior of the male rats was assessed using both standard behavioral parameters and mount bout analysis. The forced swim test, open field test, and elevated plus maze test were used to assess anxious and depressive behavior. Each rat was subjected to a single type of behavioral protocol. The inhibitory effect of maternal separation on the sexual behavior of male rats was shown by an increase in mount, intromission, and ejaculation latencies, mount and intromission frequency, and interintromission interval, and a decrease in intromission ratio. Maternally separated rats showed a delayed temporal patterning of sexual behavior. In addition, there was an increase in depressive and anxiety-like behavior in maternally separated rats. The present results suggest that perinatal stress induced by maternal separation leads to changes in sexual behavior and depressive and anxiety-like behavior in male rats. In this sense, early postnatal stress may cause behavioral changes that persist into adulthood.
