The dorsal raphe nucleus contains dopaminergic neurons that may influence social dominance in mice

• SS Tangeda

  English

  Author

• LBM Neti

  English

  Author

Individual physiology, behavior, and social
interactions are shaped by social hierarchies,
which are essential to the organizational
framework of group-living animals. Although
dopaminergic (DA) systems have been connected
to motivation and competitive behaviors,
especially in the dorsal raphe nucleus (DR) and
ventral tegmental area (VTA), their region-
specific roles in social dominance are still unclear.
In sexually naïve male C57BL/6J mice, this study
examined the function of VTA and DR DA
neurons in controlling social dominance.
Following the establishment of stable hierarchies
using the tube test, both dominant and subordinate
mice showed increased expression of c-Fos in the
VTA and DR. Interestingly, c-Fos activation in DR
DA neurons was noticeably higher in dominant
animals than in subordinates. Fiber photometry
showed that DR neurons were more strongly
engaged during dominance-related acts, while DA
neurons in both regions were suppressed during
passive retreats and activated during proactive
push behaviors. In dominant mice, chemogenetic
suppression of DR DA neurons decreased their
social rank, but in subordinate mice, activation
increased their rank. On the other hand, social
dominance was not significantly affected by
chemogenetic manipulation of VTA DA neurons.
Certain anxiety-like behavioral traits changed in a
rank-dependent manner when DA neurons in both
regions were manipulated. These results
demonstrate the different functions of DR and
VTA DA neurons in the regulation of social
hierarchy, highlighting DR DA neurons as a key
element in the control of social
dominance

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