Integrating pheromonal and spatial information in the amygdalo-hippocampal network

Male and female mice need to generate spatial maps that integrate vomeronasal signals of territory owners in the hippocampus-dependent memory. The authors show that vomeronasal information influences learning-related activity in the hippocampus via the amygdaloid PMCo, lateral entorhinal cortex, and dorsal CA1. Vomeronasal information is critical in mice for territorial behavior. Consequently, learning the territorial spatial structure should incorporate the vomeronasal signals indicating individual identity into the hippocampal cognitive map. In this work we show in mice that navigating a virtual environment induces synchronic activity, with causality in both directionalities, between the vomeronasal amygdala and the dorsal CA1 of the hippocampus in the theta frequency range. The detection of urine stimuli induces synaptic plasticity in the vomeronasal pathway and the dorsal hippocampus, even in animals with experimentally induced anosmia. In the dorsal hippocampus, this plasticity is associated with the overexpression of pAKT and pGSK3 beta. An amygdalo-entorhino-hippocampal circuit likely underlies this effect of pheromonal information on hippocampal learning. This circuit likely constitutes the neural substrate of territorial behavior in mice, and it allows the integration of social and spatial information.

Automated summary

The study demonstrates the importance of incorporating vomeronasal signals into the hippocampal cognitive map for the learning of territorial spatial structures in mice, highlighting the critical role of such information in territorial behavior. Navigating a virtual environment induces synchronic activity between the vomeronasal amygdala and the dorsal CA1 of the hippocampus in mice, indicating the influence of vomeronasal information on hippocampal learning.