Biography
Dr. Karienn A. Souza is an Assistant Professor in the Department of Neurology at UTHealth Houston’s McGovern Medical School and the Inaugural McNair Scholar. Her research focuses on understanding how disruptions in circadian rhythms, sleep, and immune function contribute to brain aging, neuroinflammation, and Alzheimer’s disease and related dementias. Her pioneering work has demonstrated that chronic circadian dysregulation accelerates biological aging and promotes long-lasting changes in brain and immune function. Her research has also revealed that circadian disruption triggers rapid activation of peripheral B cells, identifying a novel connection between circadian rhythms and immune dysregulation. Her laboratory investigates the interactions between the brain, peripheral immune system, and gut, with the goal of identifying early mechanisms of neurodegeneration and developing strategies to prevent or delay cognitive decline.
Education
- Doctorate (PhD)
- , University of Florida, McKnight Brain Institute, Gainesville, FL
- Bachelor's Degree (BS)
- Biochemistry - Department of Biochemistry, Texas A&M University, College Station, Texas
Areas of Interest
Clinical Interests
- Alzheimer’s disease and related dementias (AD/ADRD)
- Cognitive impairment and brain aging
- Sleep and circadian rhythm disturbances
- Neuroinflammation and neurodegenerative disorders
- Vascular cognitive impairment and stroke
- Sex differences in neurological disease
- Early identification of risk factors and therapeutic strategies to prevent or delay cognitive decline
Research Interests
- Alzheimer’s disease and related dementias (AD/ADRD)
- Cognitive impairment and brain aging
- Sleep and circadian rhythm disturbances; neuroinflammation and neurodegenerative disorders
- Vascular cognitive impairment and stroke
- Sex differences in neurological disease
- Early identification of risk factors and therapeutic strategies to prevent or delay cognitive decline
Publications
1. Zhang, Yuxing; ElHamamy, Ahmad; Iqbal, Zahid; Ranjan, Arya; Sumani, destiny; Souza, Karienn; Lee, Juneyoung; Marrelli, Sean; McCullough, Louise; Li, Jun. Impact of stroke on respiratory function and amyloid-β pathology in Tg-2576 mice. Journal of Alzheimer’s Disease. Accepted.
2. Barnum, E., Turck, J.L., Souza, K.A., Mani, K.K., Pilla, R., Selvamani, A., Sohrabji, F., Earnest, D.J. Sex Differences in the Effects of Controlled Circadian Dysregulation on Gut Microbiome and Intestinal Barrier Architecture. PLOS One. Accepted with revisions.
3. Huang, Y., Xie, X., Chen, R., Huang, Z., Gangal, H., Wang, X., Souza, K.A., Essoh, A., Tran, T., Chin, J.,Wang, J. Aβ Drives Corticostriatal Hyperactivity and Cholinergic Dysfunction to Impair Cognitive Flexibility in Early Alzheimer’s Disease. Nature Communications. In Press.
4. Souza, K.A., Jackson, M., Reyes, J., Muyad, J., Tran, E., Jackson, W., Newell-Rogers, M.K, Earnest, D.J. (2025) Shift Work Schedules Alter Immune Cell Regulation and Accelerate Cognitive Impairment during Aging. J. Neuroinflammation. 22, 4 (2025). https://doi.org/10.1186/s12974-024-03324-z. Corresponding author.
5. Souza, K.A., Powell, A., Allen, G.C., Earnest, D.J. (2022) Development of an Age-Dependent Cognitive Index: Relationship between Impaired Learning and Disturbances in Circadian Timekeeping. Frontiers in Aging Neuroscience 14: 991833. PMID: 36438000. Corresponding author.