Ventral dentate gyrus-dominated LFP rhythmicity in the social brain reflects the context of social encounters

Mammalian social behavior is highly context-sensitive. Yet, nothing is known about the mechanisms that modulate social behavior according to its context. Recent studies have revealed a network of mostly limbic brain regions, here termed the “social brain”, which regulates social behavior. We hypothesized that coherent theta and gamma rhythms couple regions of the social brain into functional networks in a context-dependent manner. To test this concept, we simultaneously recorded extracellular activity from multiple social brain regions in mice performing three social discrimination tasks. Local field potential rhythmicity during a task was mainly sensitive to an internal arousal state. However, during stimulus investigation we observed a distinct state, which was sensitive to stimulus characteristics. Yet, the coherence between the various regions was most sensitive to the social context. Moreover, we found the ventral dentate gyrus to play a pivotal role in coordinating the context-specific rhythmic activity in the network.