IMPACT OF PERINEURONAL NETS DEGRADATION ON SOCIAL ODOR CODING IN DORSAL HIPPOCAMPAL CA2

Social recognition in rodents relies on the hippocampal CA2, a region in which perineuronalnets (PNNs), known to regulate circuits stability, are abundant. . In this study, we investigated the impact of PNN degradation on social memory traces, by analyzing the electrophysiological responses of CA2 neurons to a battery of social odors. In detail, we performed in vivo extracellular recordings in awake, head-fixed female C57BL/6 mice using high-density multielectrode probes. Two groups of animals were compared: 4 mice received bilateral intra-hippocampal injections of Chondroitinase-ABC to enzymatically degrade PNNs, while 4 control mice were injected with Penicillinase, due to its similar enzymatic nature and its lack of activity on the extracellular matrix. During recordings, animals were exposed to various social signals including urine from different males (intact and castrated), females, and the own urine. Data were analyzed using spike sorting and firing rate quantification to characterize neuronal population dynamics. Our preliminary results show that PNN degradation may significantly impact this electrical activity. These findings point to PNNs as relevant components for the stable representation of social cues within the hippocampus and suggest that their integrity is necessary for proper social identity decoding.
Funded by Funded by Conselleria de Educación, Cultura y Universidades from the Generalitat Valenciana (CIAICO/2023/041) and the Spanish Ministry of Science, Innovation and Universities (PID2022-141733NB-I00; MCIU/ AEI /10.13039/501100011033/FEDER, UE).