Periodic Reporting for period 1 - SOFTCHIRP (Neural circuits for social communication)
Reporting period: 2022-07-01 to 2024-12-31
Vocal communication is an important component of social interaction. Yet we understand very little of the neural and molecular mechanisms that allow us to share social information through vocal cues. One current limitation is the lack of laboratory models with sufficient vocal flexibility and complexity. Naked mole-rats are subterranean rodents with a highly specialized cooperative and hierarchical social structure. Colonies are organized to support a single breeding female and her progeny with numerous non-reproductive workers sharing communal tasks for colony maintenance and defense. This type of social organization, eusociality, which is common in many insects is rare in mammals. In fact, naked mole-rats are one of only two mammals that exhibit this type of extreme cooperative behavior. We previously identified that naked mole-rats are highly vocal, using vocalizations to communicate information about individual identity and colony membership. We are now focusing on understanding how the brain of the naked mole-rat is specialized to encode and decode socially meaningful sounds and how these representations are updated when social situations change. We are using a combination of neural recordings, molecular biology and behavioral monitoring to investigate how the brains of these animals are specialized to process and produce socially meaningful sounds. The overall objectives of the project are divided into three main projects aimed towards understanding (i) how social identity is encoded at the earliest stages of auditory processing within the naked mole-rat brain, (ii) how social interactions acting through transcriptomic and molecular mechanisms influence vocal behaviors and finally (iii) how neural circuits for vocal production are shaped by auditory environments during development. This work has the potential to not only expand our understanding of the neural architecture underling the sensory coding and the production of vocalizations, but also to provide insights into complex social behaviors such as empathy and altruism.
In the first reporting period, we developed a behavioral tracking system for real time monitoring of position, audio and video of naked mole-rats in a naturalistic habitat. This allows for long-term, highly quantifiable monitoring of how social dynamics within colonies evolve over time and how vocal communication shapes social behavior, forming the foundation for much of the future work in the project. In addition, we have made significant strides in the development of tools for in vivo recording of neural activity in the naked mole-rat brain. In particular we have established a protocol for viral-mediated delivery of genetically encoded calcium indicators which can be used to measure neural activity and adapted standard techniques for neural probe recordings to the naked mole-rat. To our knowledge this is the first report of these techniques being implemented in this species. We are now leveraging these tools to answer several key questions related to the neural mechanisms of vocal communication in naked mole-rats. For example, we can now begin to study how individual identity encoded in vocal cues is represented in the brain. In addition, we are investigating how vocal cues for identity and colony membership emerge during development and how are they updated as social dynamics within the colony change.
We have developed and adapted protocols for the in vivo recording of neural activity in naked mole-rats. To our knowledge this is the first implementation of these techniques in this species. In the subsequent reporting period we will leverage these tools to answer fundamental questions about the behavior and brains of the naked mole-rat.