Oxytocinergic Feedback Circuitries: An Anatomical Basis for Neuromodulation of Social Behaviors

Abstract

Oxytocin (OT) is a neuropeptide produced by hypothalamic neurons and is known to modulate social behavior among other functions. Several experiments have shown that OT modulates neuronal activity in many brain areas, including sensory cortices. OT neurons thus project axons to various cortical and subcortical structures and activate neuronal subpopulations to increase the signal-to-noise ratio, and in turn, increases the saliency of social stimuli. Less is known about the origin of inputs to OT neurons, but recent studies show that cells projecting to OT neurons are often located in regions where the OT receptor (OTR) is expressed. Thus, we propose the existence of reciprocal connectivity between OT neurons and extrahypothalamic OTR neurons to tune OT neuron activity depending on the behavioral context. Furthermore, the latest studies have shown that OTR-expressing neurons located in social brain regions also project to other social brain regions containing OTR-expressing neurons. We hypothesize that OTR-expressing neurons across the brain constitute a common network coordinated by OT.

Oxytocin signaling in the posterior hypothalamus prevents hyperphagic obesity in mice

“…Our data showed that PVH Oxt neurons mediated appetite suppression signals. Previous studies have shown that both oxytocinergic neurites and Oxtr -expressing neurons can be found in various brain and spinal cord regions ( Jurek and Neumann, 2018 ; Lefevre et al, 2021 ; Newmaster et al, 2020 ; Oti et al, 2021 ; Zhang et al, 2021 ). In the present study, by AAV-Cre -mediated cKO, we found that Oxtr expressed by neurons in the posterior hypothalamic regions, especially those in the ARH, mediates appetite suppression signals ( Figures 5 and 6 ).…”

Oxytocin signaling in the posterior hypothalamus prevents hyperphagic obesity in mice

“…Our data showed that PVH OT neurons mediated appetite-suppression signals. Previous studies have shown that both oxytocinergic neurites and OTR-expressing neurons can be found in various brain and spinal cord regions (Jurek and Neumann, 2018; Lefevre et al, 2021; Newmaster et al, 2020; Oti et al, 2021; Zhang et al, 2021). In the present study, by AAV-Cre mediated cKO, we found that OTR expressed by neurons in the posterior hypothalamic regions, especially those in the ARH, mediates appetite-suppression signals (Figure 5 and 6).…”

Interplay between the oxytocin and opioid systems in regulating social behaviour

“…This review will specifically highlight interactions between oxytocin and opioidergic circuits [82]. Existing reviews have done an excellent job summarizing known behavioural effects of oxytocin [43,48,50,52,58,71,82,83], the neural mechanisms underlying these effects [15][16][17]84,85] and potential hypotheses about the role of oxytocin in the brain and social behaviour [20,22,24]. We will not attempt to duplicate those here.…”