Impaired social contacts with familiar anesthetized conspecific in CA3‐restricted brain‐derived neurotrophic factor knockout mice

Abstract

Familiarity is conveyed by social cues and determines behaviors toward conspecifics. Here, we characterize a novel assay for social behaviors in mice-contacts with anesthetized conspecific-which eliminates reciprocal interactions, including intermale aggression and shows behaviors that are independent of the demonstrator's activity. During the initial 10 minutes (phase-1), the wild-type (WT) subjects contacted the anesthetized conspecifics vigorously regardless of familiarity. During the subsequent 80 minutes (phase-2), however, they contacted more with familiar than unfamiliar conspecifics. We then applied this test to highly aggressive mice with a hippocampal CA3-restricted knockout (KO) of brain-derived neurotrophic factor (BDNF), in which aggression may mask other social behaviors. The KO mice showed less preference for contacting familiar conspecifics than did WT mice during phase-2 but no differences during phase-1. Among nonsocial behaviors, WT mice also spent less time eating in the presence of familiar than with unfamiliar conspecifics, which was not seen in KO mice. In addition, KO mice exhibited reduced pain sensitization. Altogether, these findings suggest that CA3-specific deletion of BDNF results in deficits in circuits that process social cues from familiar conspecifics as well as pain and may underlie empathy-like behaviors.

Social context modulates multibrain broadband dynamics and functional brain-to-brain coupling in the group of mice

“…We used huddling as an easily identifiable social state. Huddling, a stable aggregation of animals, is both social and thermo-adaptive and is exclusively present in social context 17 , 18 . In addition, we used a head-mountable wireless edge-computing system capable of more than three-hour neural recordings to understand the multi-brain dynamics of a group of mice.…”

Social context modulates multibrain broadband dynamics and functional brain-to-brain coupling in the group of mice

“…We utilized huddling as easily identifiable social states. Huddling, a stable aggregation of animals, is both social and thermoadaptive behavior and is exclusively present in social conditions (Ito et al, 2019; Kojima & Alberts, 2011). In addition, we exploited head-mountable wireless edge-computing system capable of more than three-hour neural recording to understand multibrain dynamics of group of mice.…”

The neuroscience and genomics of social behavior

“…Many potential candidate mechanisms have now been proposed. Here, Ito et al 17 show that mice with deletion of brain-derived neurotrophic factor ( Bdnf ), specifically within the CA3 subregion of the hippocampus, showed deficient interaction with a familiar, but anesthetized, conspecific. Their reason for developing this novel procedure was to minimize the hyper-aggression that is normally elicited by an awake social partner in these mutants and thereby better parse out this social deficit.…”