Fig. 2

The augmentation of Oxytocin expression. a a illustration of early life stress. b and c, both oxytocin mRNA level and protein level were significantly increased in predictable maternal separation (mild early life stress), while were decreased in unpredictable maternal separation. a-c adapted from [9]. d copulation (i.e., acute effects of sexual activity) increases OXTR mRNA levels in the medial preoptic area (MPOA). e Previous sexual experience increases OXTR protein levels in the MPOA, ventromedial hypothalamus. d and e adapted from [148]. f Setup for recordings of behavior, ultrasonic vocalizations and neural activity. g Average firing rate of 15 OXT neurons from 5 rats. Free social interactions (FSI) led to the greatest change in firing rate and synchronous activity in simultaneously recorded OXT neurons. h Frames of recorded videos (top) of experimental rats that were placed either alone (Open field exploration), or with a mesh between rats (Chambered social interaction) or for FSI with a stimulus rat; representative spike raster plots of an OXT cell in each condition (bottom). experimental and stimulus rats were separated by a transparent wall with small holes (7.5 mm), allowing rats to see, sniff and hear, but not touch, each other. i Representative spike raster plots, averaged response and peristimulus time histograms of OXT cell activity during ‘crawling on top’. f–i adapted from [151]