Auditory object representation in the bat hippocampus.

Cognitive maps enable the flexible selection of navigation paths. Acoustic cognitive maps, constructed from the spatial layout of sonar auditory objects, support bat navigation in natural settings; however, the neural building blocks of acoustic maps remain unknown. Here, we demonstrate auditory object representation in the hippocampus of echolocating bats and test the hypothesis that active tracking drives hippocampal auditory object representation. We discovered two distinct populations of hippocampal CA1 neurons, one encoding allocentric object location and another, egocentric object distance. During trials when the bat ceased object tracking, the spatial code degraded. These findings reveal that auditory information alone can drive the construction of cognitive maps of space, with hippocampal auditory object representations activated by the animal's sonar tracking.