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The impact of suppressing core regions of the DMN on brain network dynamics and behavior
https://repo.qst.go.jp/records/2002509
https://repo.qst.go.jp/records/200250903208ff2-4eac-4a0b-be8b-02c725d269e9
| アイテムタイプ | 会議発表用資料 / Presentation(1) | |||||||
|---|---|---|---|---|---|---|---|---|
| 公開日 | 2025-11-07 | |||||||
| タイトル | ||||||||
| タイトル | The impact of suppressing core regions of the DMN on brain network dynamics and behavior | |||||||
| 言語 | ja | |||||||
| 言語 | ||||||||
| 言語 | jpn | |||||||
| 資源タイプ | ||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||||
| 資源タイプ | conference presentation | |||||||
| 著者 |
堀 祐樹
× 堀 祐樹
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| 抄録 | ||||||||
| 内容記述 | The default mode network (DMN) is a large-scale brain network comprising regions such as the posterior parietal cortex (PPC) and posterior cingulate cortex (PCC). In humans, the DMN has been implicated in internally oriented processes, including self-referential thought and social cognition, and its dysfunction is associated with psychiatric conditions such as autism spectrum disorder and schizophrenia. However, the causal contributions of the DMN to social cognition remain poorly understood due to the complexity of the network. The aim of this study is to elucidate how suppression of PPC and PCC, hub regions of the DMN, affects whole-brain network organization, and to determine how these alterations causally contribute to higher-order functions such as social cognition. To address this, we chemogenetically manipulated key DMN nodes in nonhuman primates and assessed the impact on network connectivity and social attention. Four macaque monkeys received injections of adeno-associated virus vectors to express either an inhibitory designer receptor (hM4Di; N=2) or a combination of hM4Di and an inhibitory designer channel (PSAM4-GlyR) in the PPC and PCC nodes. Systemic administration of the corresponding agonists—deschloroclozapine (DCZ) and uPSEM817 (0.1 mg/kg)—induced targeted chemogenetic inhibition, confirmed by significant reductions in local BOLD signals (p < 0.001) using pharmacological MRI. Resting-state fMRI showed that inhibition of either PPC or PCC alone produced only limited reductions in DMN functional connectivity. In contrast, simultaneous inhibition of both nodes substantially disrupted intra-DMN connectivity (27% reduction, p<0.05), indicating that PPC and PCC contribute synergistically to maintaining DMN activity. Functional connectivity within other large-scale networks remained unchanged, highlighting the specificity of DMN suppression. To assess behavioral consequences, two monkeys were tested using a free-viewing paradigm in which they explored three categories of visual stimuli: background scenes, a single monkey, and two monkeys engaging in social interaction. DMN suppression did not affect gaze allocation to background scenes or single monkeys. However, during social scene presentation it selectively altered gaze patterns—reducing gaze toward interaction regions between monkeys while increasing gaze toward individual monkey faces. These results provide causal evidence that DMN activity is critical for guiding attention toward socially relevant interactions, supporting its role in a core aspect of social cognition. | |||||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||||
| 内容記述 | QST-ANC International Symposium on Primate Research | |||||||
| 発表年月日 | ||||||||
| 日付 | 2025-07-22 | |||||||
