| First Author | Loisy M | Year | 2022 |
| Journal | Neuron | Volume | 110 |
| Issue | 17 | Pages | 2854-2866.e4 |
| PubMed ID | 35858622 | Mgi Jnum | J:328361 |
| Mgi Id | MGI:7335910 | Doi | 10.1016/j.neuron.2022.06.013 |
| Citation | Loisy M, et al. (2022) Sequential inhibitory plasticities in hippocampal area CA2 and social memory formation. Neuron 110(17):2854-2866.e4 |
| abstractText | Area CA2 is a critical region for diverse hippocampal functions including social recognition memory. This region has unique properties and connectivity. Notably, intra-hippocampal excitatory inputs to CA2 lack canonical long-term plasticity, but inhibitory transmission expresses a long-term depression mediated by Delta-opioid receptors (DOR-iLTDs). Evidence indicates that DOR-iLTDs are insufficient to underlie social coding. Here, we report a novel inhibitory plasticity mediated by cannabinoid type 1 receptor activation (CB1R-iLTD). Surprisingly, CB1R-iLTD requires previous induction of DOR-iLTDs, indicating a permissive role for DOR plasticity. Blockade of CB1Rs in CA2 completely prevents social memory formation. Furthermore, the sequentiality of DOR- and CB1R-mediated plasticity occurs in vivo during successive social interactions. Finally, CB1R-iLTD is altered in a mouse model of schizophrenia with impaired social cognition but is rescued by a manipulation that also rescues social memory. Altogether, our data reveal a unique interplay between two inhibitory plasticities and a novel mechanism for social memory formation. |
