Social behavior in mice is critical for understanding their natural interactions and underlying neural mechanisms. Traditional Markov models, however, face limitations in capturing the sequential dynamics of body language associated with social behaviors. To address these challenges, we developed the body language-bidirectional encoder representation from transformers (BL-BERT) framework, which surpasses the Markov model in extracting complex sequential behavioral patterns. BL-BERT effectively differentiates the body language of the mice within different social interaction paradigms and produces results consistent with manual annotations. Notably, BL-BERT achieves higher extraction accuracy than the Markov model by reducing the complexity of the recurrent state transitions in behavior sequences. These advantages enable BL-BERT to accurately quantify high-order sequential behavioral structures in mice, paving the way for more detailed insights into the brain’s mechanisms controlling complex behavior.

Recent advances in optogenetics have established a precisely timed and cell-specific methodology for understanding the functions of brain circuits and the mechanisms underlying neuropsychiatric disorders. However, the fabrication of optrodes, a key functional element in optogenetics, remains a great challenge. Here, we report reliable and efficient fabrication strategies for chronically implantable optrode arrays. To improve the performance of the fabricated optrode arrays, surfaces of the recording sites were modified using optimized electrochemical processes. We have also demonstrated the feasibility of using the fabricated optrode arrays to detect seizures in multiple brain regions and inhibit ictal propagation in vivo. Furthermore, the results of the histology study imply that the electrodeposition of composite conducting polymers notably alleviated the inflammatory response and improved neuronal survival at the implant/neural-tissue interface. In summary, we provide reliable and efficient strategies for the fabrication and modification of customized optrode arrays that can fulfill the requirements of in vivo optogenetic applications.