Representation of sounds in the cortex of naked mole-rats

Naked mole-rats are small rodents with very elaborate colony organization with up to 300 members. Their colonies structure is highly hierarchical and cooperative. Naked mole-rats have a rich vocal repertoire that consists of ~25 vocalization types. The most commonly used vocalizations are the so-called soft chirps (SC). SC are used antiphonally with repeated call and response bouts between colony mates. Acoustic playbacks of SC elicit vocal responses in receiver animals, only if the SC belong to a member of the same colony as the listener. This behavior requires an exquisite discrimination of the acoustics of SC. Although machine learning classifiers showed that SC encode information about colony membership, it is unknown how these vocalizations are encoded in the brain of these animals. Sensory cortices are particularly plastic compared with lower system levels. The functional structure of cortex is continuously modified by an animal’s sensory experience. Considering this, we hypothesize that a fine discrimination of colony SC takes place in cortical neurons. To answer this, we perform in vivo electrophysiology recordings across cortical layers and quantitatively evaluate physiological responses to natural vocalizations and to synthetic sounds. We expect that SC will be represented differentially in the cortex compared to other sounds that are acoustically similar but rarely encountered in the life of these animals.