Testosterone administration modulates neural responses to crying infants in young females
Peter A Bos1, Erno J Hermans, Estrella R Montoya
1Utrecht University, Department of Experimental Psychology, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands. p.a.bos@uu.nl
Insights
Testosterone administration in women heightened brain activity in the thalamocingulate circuit when listening to infant cries. This suggests testosterone may upregulate parental care mechanisms via this neural pathway.
Area of Science:
- Neuroscience
- Endocrinology
- Developmental Psychology
Background:
- Parental responsiveness to infant vocalizations is crucial for caregiving.
- The thalamocingulate circuit is a key neural substrate for parental responsiveness.
- Steroid hormones like testosterone and estradiol may mediate parental behavior.
Purpose of the Study:
- To investigate the role of testosterone in parental responsiveness to infant cries.
- To examine the neural mechanisms underlying testosterone's effect on parental care.
Main Methods:
- Functional Magnetic Resonance Imaging (fMRI) was used to measure brain activity.
- A double-blind, placebo-controlled, counterbalanced testosterone administration experiment was conducted on 16 young women.
- Participants listened to infant crying stimuli.
Main Results:
- Testosterone administration led to heightened activation in the thalamocingulate region, insula, and cerebellum in response to infant cries compared to placebo.
- This confirms the involvement of the thalamocingulate circuit in processing infant cries.
Conclusions:
- Exogenous testosterone influences the thalamocingulate circuit in women.
- Testosterone may play a role in upregulating parental care, potentially via the thalamocingulate circuit and its metabolite estradiol.
Abstract:
Parental responsiveness to infant vocalizations is an essential mechanism to ensure parental care, and its importance is reflected in a specific neural substrate, the thalamocingulate circuit, which evolved through mammalian evolution subserving this responsiveness. Recent studies using functional Magnetic Resonance Imaging (fMRI) provide compelling evidence for a comparable mechanism in humans by showing thalamocingulate responses to infant crying. Furthermore, possibly acting on this common neural substrate, steroid hormones such as estradiol and testosterone, seem to mediate parental behavior both in humans and other animals. Estradiol unmistakably increases parental care, while data for testosterone are less unequivocal. In humans and several other animals, testosterone levels decrease both in mothers and fathers during parenthood. However, exogenous testosterone in mice seems to increase parenting, and infant crying leads to heightened testosterone levels in human males. Not only is the way in which testosterone is implicated in parental responsiveness unresolved, but the underlying mechanisms are fully unknown. Accordingly, using fMRI, we measured neural responses of 16 young women who were listening to crying infants in a double blind, placebo-controlled, counterbalanced, testosterone administration experiment. Crucially, heightened activation in the testosterone condition compared to placebo was shown in the thalamocingulate region, insula, and the cerebellum in response to crying. Our results by controlled hormonal manipulation confirm a role of the thalamocingulate circuit in infant cry perception. Furthermore, the data also suggest that exogenous testosterone, by itself or by way of its metabolite estradiol, in our group of young women acted on this thalamocinculate circuit to, provisionally, upregulate parental care.
