Frontal glutamatergic synapses are thought to be critical for adaptive, long-term stress responses. Prefrontal cortices, including the anterior cingulate cortex (ACC) contribute to stress perception and regulation, and are involved in top-down regulation of peripheral glucocorticoid and inflammatory responses to stress. Levels of kynurenic acid (KYNA) in saliva increase in response to psychological stress, and this stress-induced effect may be abnormal in people with schizophrenia. Here we test the hypothesis that ACC glutamatergic functioning may contribute to the stress-induced salivary KYNA response in schizophrenia. In 56 patients with schizophrenia and 58 healthy controls, our results confirm that levels of KYNA in saliva increase following psychological stress. The magnitude of the effect correlated negatively with proton magnetic resonance spectroscopy (MRS) glutamate + glutamine (r = -.31, p = .017) and glutamate (r = -0.27, p = .047) levels in the ACC in patients but not in the controls (all p ≥ .45). Although, a causal relationship cannot be ascertained in this cross-sectional study, these findings suggest a potentially meaningful link between central glutamate levels and kynurenine pathway response to stress in individuals with schizophrenia.

中文翻译：

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唾液尿尿酸对心理压力的反应：与精神分裂症的皮质谷氨酸成反比。

额叶谷氨酸能突触被认为对适应性长期应激反应至关重要。前额叶皮层，包括前扣带回皮层（ACC）有助于压力感知和调节，并参与自上而下的外周糖皮质激素调节和对压力的炎症反应。唾液中的犬尿尿酸（KYNA）的水平会因心理压力而增加，这种压力诱导的作用在精神分裂症患者中可能是异常的。在这里，我们测试了ACC谷氨酸能功能可能有助于精神分裂症中应激诱导的唾液KYNA反应的假说。在56位精神分裂症患者和58位健康对照中，我们的结果证实，在心理压力后，唾液中KYNA的水平会升高。效应的程度与患者ACC中的质子磁共振波谱（MRS）谷氨酸+谷氨酰胺（r = -.31，p = .017）和谷氨酸（r = -0.27，p = .047）水平呈负相关，但不在控件中（所有p≥.45）。尽管在本项横断面研究中无法确定因果关系，但这些发现表明，精神分裂症患者的中央谷氨酸水平和犬尿氨酸途径对应激的反应之间可能存在有意义的联系。