Testosterone Promotes Paternal Behaviour In A Monogamous Mammal Via Conversion To Oestrogen

[Lucenzo01]

Although high testosterone (T) levels inhibit paternal behaviour in birds breeding in temperate zones many paternal mammals have a very different breeding biology, characterized by a post-partum oestrus. In species with post-partum oestrus, males may engage in T-dependent behaviours such as aggression and copulation simultaneously with paternal behaviour. We previously found that T promotes paternal behaviour in the California mouse, Peromyscus californicus. We examine whether this effect is mediated by the conversion of T to oestradiol (E(2)) by aromatase. In the first experiment, gonadectomized males treated with T or E(2) implants showed higher levels of huddling and pup grooming behaviour than gonadectomized males treated with dihydrotestosterone or empty implants. In the second experiment, we used an aromatase inhibitor (fadrozole) (FAD) to confirm these results. Gonadectomized males treated with T + vehicle or E(2) + FAD showed higher levels of huddling and pup grooming behaviour than gonadectomized males treated with T + FAD or empty implants. Although E(2) is known to promote the onset of maternal behaviour to our knowledge our results are the first to demonstrate that E(2) can promote paternal behaviour in a paternal mammal. These results may explain how mammals express paternal behaviour while T levels are elevated.

 

[bdawg]

Although high testosterone (T) levels inhibit paternal behaviour in birds breeding in temperate zones many paternal mammals have a very different breeding biology, characterized by a post-partum oestrus. In species with post-partum oestrus, males may engage in T-dependent behaviours such as aggression and copulation simultaneously with paternal behaviour. We previously found that T promotes paternal behaviour in the California mouse, Peromyscus californicus. We examine whether this effect is mediated by the conversion of T to oestradiol (E(2)) by aromatase. In the first experiment, gonadectomized males treated with T or E(2) implants showed higher levels of huddling and pup grooming behaviour than gonadectomized males treated with dihydrotestosterone or empty implants. In the second experiment, we used an aromatase inhibitor (fadrozole) (FAD) to confirm these results. Gonadectomized males treated with T + vehicle or E(2) + FAD showed higher levels of huddling and pup grooming behaviour than gonadectomized males treated with T + FAD or empty implants. Although E(2) is known to promote the onset of maternal behaviour to our knowledge our results are the first to demonstrate that E(2) can promote paternal behaviour in a paternal mammal. These results may explain how mammals express paternal behaviour while T levels are elevated.

Very interesting, I wonder what causes the increase in E conversion for fathers:

https://www.scientificamerican.com/article/fathers-to-be-may-have-hormonal-changes-too/

And I also wonder what kind of a father a non-aromatizer DHT dominant male would be.....

 

[schultz]

Very interesting, I wonder what causes the increase in E conversion for fathers:

https://www.scientificamerican.com/article/fathers-to-be-may-have-hormonal-changes-too/

And I also wonder what kind of a father a non-aromatizer DHT dominant male would be.....

It's been a while, but I remember reading that a crying baby can cause some hormonal changes in men. It's an interesting topic.

Hormone changes or not, I wouldn't trade anything for my kids. A real man has offspring and ensures that they are raised properly. All other males are still boys in my book. (my apologies if that is offensive to anybody ) ... (emoji's are manly in my world!! )

 

[bdawg]

It's been a while, but I remember reading that a crying baby can cause some hormonal changes in men. It's an interesting topic.

Hormone changes or not, I wouldn't trade anything for my kids. A real man has offspring and ensures that they are raised properly. All other males are still boys in my book. (my apologies if that is offensive to anybody ) ... (emoji's are manly in my world!! )

I happen to agree with you, hope to have a few kids down the line...