Acute stress affects interoception, but it remains unclear if this is due to activation of the sympatho-adreno-medullary (SAM) or hypothalamic–pituitary–adrenocortical axis. This study aimed to investigate the effect of SAM axis activation on interoceptive accuracy (IAcc). Central alpha2-adrenergic receptors represent a negative feedback mechanism of the SAM axis. Major depressive disorder and adverse childhood experiences (ACE) are associated with alterations in the biological stress systems, including central alpha2-adrenergic receptors. Here, healthy individuals with and without ACE as well as depressive patients with and without ACE (n = 114; all without antidepressant medication) were tested after yohimbine (alpha2-adrenergic antagonist) and placebo. We assessed IAcc and sensibility in a heartbeat counting task. Increases in systolic and diastolic blood pressure after yohimbine confirmed successful SAM axis activation. IAcc decreased after yohimbine only in the healthy group with ACE, but remained unchanged in all other groups (Group × Drug interaction). This effect may be due to selective upregulation of alpha2-adrenergic receptors after childhood trauma, which reduces capacity for attention focus on heartbeats. The sympathetic neural pathway including alpha2-adrenergic circuitries may be essential for mediating interoceptive signal transmission. Suppressed processing of physical sensations in stressful situations may represent an adaptive response in healthy individuals who experienced ACE.

急性压力会影响内感受，但尚不清楚这是否是由于激活了交感-肾上腺-髓质 (SAM) 或下丘脑-垂体-肾上腺皮质轴。本研究旨在研究 SAM 轴激活对内感受准确度 (IAcc) 的影响。中枢 α2-肾上腺素能受体代表 SAM 轴的负反馈机制。重度抑郁症和不良童年经历 (ACE) 与生物应激系统的改变有关，包括中枢 α2-肾上腺素能受体。在这里，有和没有 ACE 的健康个体以及有和没有 ACE 的抑郁患者（n= 114; 在育亨宾（α2-肾上腺素能拮抗剂）和安慰剂之后进行了测试。我们在心跳计数任务中评估了 IAcc 和敏感性。育亨宾证实成功激活 SAM 轴后收缩压和舒张压升高。育亨宾后 IAcc 仅在具有 ACE 的健康组中降低，但在所有其他组中保持不变（组 × 药物相互作用）。这种效应可能是由于儿童创伤后 α2-肾上腺素能受体的选择性上调，这降低了将注意力集中在心跳上的能力。包括α2-肾上腺素能电路在内的交感神经通路可能对于介导内感受信号传递至关重要。