Strange females increase plasma testosterone levels in male mice.
Level 5 - mechanism / opinion, no new human data
Non-human animal study
PubMed 1162363 · doi:10.1126/science.1162363
What was done
Male house mice paired with a normal female for 1 week were evaluated for plasma testosterone changes under different social manipulations: remaining with the familiar female, comparison to all-male housing, replacement of the resident female with a novel (strange) female, replacement with a novel male, or initial pairing following isolation. Conditions were evaluated at 30 to 60 minutes post-exposure, including under housing allowing ambient odor exposure and accounting for whether copulation occurred.
What was found
Males paired with a female for 1 week had plasma testosterone levels comparable to males in all-male groups. Introducing a strange female in place of the resident female led to markedly elevated plasma testosterone levels at 30 to 60 minutes. This surge was similar in magnitude to that observed when isolated males were first paired with a female, did not require copulation, persisted in the presence of background male and female odors, and did not occur when the female was replaced with an unfamiliar male. The abstract reports directional patterns without exact numerical concentrations.
Why it matters
This study demonstrates a rapid and specific neuroendocrine response in male mammals triggered by novel social and sexual cues rather than physical copulation alone.
Limits
The abstract provides no sample sizes, variance metrics, or exact hormone concentrations. Findings are restricted to male house mice and cannot be directly generalized to other species or humans.
Cited by
- supports Exposure to the odors of a receptive female causes a spike in testosterone levels in male animals.