Bio

Bio


Dr. Zhang received her Ph.D. degree in 2019 in Biomedical Engineering from Tsinghua University School of Medicine. She was a Visiting Student Researcher in the Radiology Department at Stanford in 2017-2018. Her dissertation research focused on identifying neuroimaging markers for depression vulnerability through fMRI and simultaneous fPET-fMRI.

Dr. Zhang was interested in methods development for dynamic fMRI and fPET analysis, especially in characterizing brain dynamics through resting-state fMRI in psychiatric diseases (depression and anxiety).

Dr. Zhang joined PanLab in 2020 on two projects: 1) examining human structural and functional changes relevant to drug abuse on the brain’s risk and reward circuits; 2) engaging self-regulation targets to understand the mechanisms of behavior change and improve mood and weight outcomes (ENGAGE).

Professional Education


  • Bachelor of Engineering, Capital Medical University (2013)
  • Doctor of Philosophy, Tsinghua University (2019)

Stanford Advisors


Publications

All Publications


  • Dynamic changes in thalamic connectivity following stress and its association with future depression severity BRAIN AND BEHAVIOR Zhang, X., Li, X., Steffens, D. C., Guo, H., Wang, L. 2019; 9 (12): e01445

    Abstract

    Tracking stress-induced brain activity and connectivity dynamically and examining activity/connectivity-associated recovery ability after stress might be an effective way of detecting stress vulnerability.Using two widely used stress paradigms, a speech task (social stress) and a mathematical calculation task (mental loading stress), we examined common changes in regional homogeneity (ReHo) and functional connectivity (FC) before, during, and after the two stressful tasks in thirty-nine college students. A counting breath relaxation task was employed as a contrast task. ReHo and FC were compared between subjects with higher versus lower depression symptoms (assessed by the Beck Depression Inventory, BDI). We developed a recovery index (RI) based on dynamic changes of ReHo/FC to evaluate individuals' ability to recover from a stressful state. To assess RI's usefulness in predicting future depression severity, BDI was also measured at one-year follow-up.Our results revealed a ReHo decrease after both stressful tasks and a ReHo increase after the relaxation task in bilateral thalamus. The ReHo decrease after both stressful tasks was more significant in the higher BDI than the lower BDI group. Higher ReHo RI of the right thalamus in the higher BDI groups was significantly correlated with lower BDI severity at one-year follow-up. Bilateral thalamus also showed increased FC with the default mode network and decreased FC with the executive control network after the stressful tasks.These findings highlight the importance of tracking resting activity and connectivity of thalamus dynamically for detecting stress vulnerability.

    View details for DOI 10.1002/brb3.1445

    View details for Web of Science ID 000492395500001

    View details for PubMedID 31651099

    View details for PubMedCentralID PMC6908855

  • Exploring common changes after acute mental stress and acute tryptophan depletion: Resting-state fMRI studies JOURNAL OF PSYCHIATRIC RESEARCH Zhang, X., Huettel, S. A., Mullette-Gillman, O. A., Guo, H., Wang, L. 2019; 113: 172–80

    Abstract

    Stress and low serotonin levels are important biological factors in depression and anxiety etiologies. Although studies indicate that low serotonin levels, stress, and other factors may interact in depression/anxiety psychopathology, few studies have investigated the potentially shared neural substrates. We conducted resting-state fMRI scans pre- and post-stress task, and under control and tryptophan depletion condition, to explore the common changes induced by acute mental stress (AMS) and acute tryptophan depletion (ATD). The present study targeted regions within core brain networks - default mode network, salience network, executive control network, and emotion network - reported altered in AMS and ATD, and used regional homogeneity (ReHo) and functional connectivity (FC) analyses to explore their overlapped effects. We additionally examined the relationships among core neural networks - operationalized as an index of resource allocation bias that quantifies the shift from internal to external modes of processing. We found both manipulations induced increased ReHo of the amygdala and decreased ReHo of the posterior cingulate cortex (PCC). The PCC-amygdala FC was negatively correlated with the change of negative affect, whereas the right dorsolateral prefrontal cortex and right anterior insula FC was positively associated with anxiety level. In addition, we found that a greater shift to an external mode was correlated with higher anxiety level under both conditions. Common changes induced by acute mental stress and acute tryptophan depletion confirmed our hypothesis that AMS and ATD induce changes in common neural pathways, which in turn might mark vulnerability to depression and anxiety.

    View details for DOI 10.1016/j.jpsychires.2019.03.025

    View details for Web of Science ID 000467670000025

    View details for PubMedID 30959228

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