Here Comes Optomom!

Optogenetic manipulation in a naïve female mouse induces maternal behavior in response to pup distress calls (Marlin et al. 2015).

Video 6: Pup retrieval by Oxt-IRES-Cre virgin female after optical stimulation of left primary auditory cortex (Marlin et al. 2015).

One of the really amazing things is that neural activity in response to the distress cries is left lateralized in the auditory cortex. In a mouse!

This is markedly similar to the asymmetry of speech processing in human temporal lobe^{43, 44}, and supports earlier behavioural observations of auditory lateralization in maternal mice¹⁹.

A number of separate experiments showed that the hypothalamic hormone oxytocin was a key player in modulating neural activity and behavioral responses to the pup’s calls, with the requisite demonstrations of maternal behavior being turned on and off at the will of the investigators.

An extensive literature (dating back to the 1940s-50s) has already established that oxytocin plays a role in promoting maternal behavior, so that part did not come as a surprise (e.g., Pedersen et al., 1982). But modern optogenetic methods provide more precise control of specific neuron populations (and more dramatic videos).

Media outlets: do not extrapolate from this mouse study to potential interventions in neglectful human mothers. There are no implants for bad moms!

 

Reference

Marlin, B., Mitre, M., D’amour, J., Chao, M., & Froemke, R. (2015). Oxytocin enables maternal behaviour by balancing cortical inhibition. Nature DOI: 10.1038/nature14402