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Dr. Ioana Carcea (Rutgers University)

• “Social transmission of behavioral responses to distress calls”
• Maternal care, including by non-biological parents, is important for offspring survival. Oxytocin, which is released by the hypothalamic paraventricular nucleus (PVN), is a critical maternal hormone. In mice, oxytocin enables neuroplasticity in the auditory cortex for maternal recognition of pup distress. However, it is unclear how initial parental experience promotes hypothalamic signalling and cortical plasticity for reliable maternal care. We continuously monitored the behaviour of female virgin mice co-housed with an experienced mother and litter. This documentary approach was synchronized with neural recordings from the virgin PVN, including oxytocin neurons. These cells were activated as virgins were enlisted in maternal care by experienced mothers, who shepherded virgins into the nest and demonstrated pup retrieval. Virgins visually observed maternal retrieval, which activated PVN oxytocin neurons and promoted alloparenting. Thus rodents can acquire maternal behaviour by social transmission, providing a mechanism for adapting the brains of adult caregivers to infant needs via endogenous oxytocin.

Dr. Liberty Hamilton (University of Texas at Austin)

• “A parallel pathway for speech that bypasses primary auditory cortex”
• A prevailing view of information flow through the auditory pathway posits that speech sounds are processed through a hierarchy from brainstem to thalamus to the primary auditory cortex and out to speech cortex on the superior temporal gyrus. Using a combination of high resolution ECoG grid recordings across the lateral superior temporal gyrus (STG) and core auditory areas on the temporal plane, cortical stimulation, and ablation, we show that this may not be the case. Instead, we find an area of the posterior STG that is activated in parallel to the primary auditory cortex at indistinguishable latencies. Stimulation of the primary auditory cortex does not appear to interfere with speech perception, which would be predicted if it provided the sole inputs to this area. I will discuss these results and implications for brain processing of speech.