Behaviors essential for survival, including parenting behaviors, are driven by neural circuits that arise from combinations of genetics and experience-dependent learning. To what extent is parental behavior learned, vs. predetermined by innate specializations of neural circuits? Virgin female mice can learn some maternal behaviors when housed with an experienced mother and her pups, in particular retrieving isolated pups to the nest. Preliminary data indicates that virgins can learn this behavior via auditory and visual observation. In both mothers and pup-experienced virgins, retrieval behavior is correlated with plasticity in sensory areas of the brain, including heightened sensitivity for pup vocalizations in auditory cortex. This robustly-learned, socially- transmitted behavior is an ideal model for measuring synaptic plasticity correlated with learning in a naturalistic context. In this proposal I will use a head-fixed virtual reality paradigm combined with whole-cell electrophysiology and functional imaging to measure plasticity induced by observation in real time. I will deconstruct what specific combinations of visual and auditory cues refine auditory cortex tuning for pup vocalizations, enabling mice to categorize these sounds as behaviorally salient. I will use functional imaging and optogenetic manipulations to measure the dynamics of neuromodulatory activity required for induction and maintenance of this plasticity.
The ability of mothers to detect and adequately respond to sensory cues from infants is essential for survival in most mammals. Many maternal behaviors related to this have long been considered hard-wired or innate, but can be learned by non-mothers via social transmission and observation. The proposed research will examine the neural circuit and synaptic plasticity underlying observational learning of a key maternal behavior in mice, in which mother mice retrieve isolated pups into the nest in response to pup vocalizations.
