The role of oligodendrocytes and myelin in differential susceptibility to stress-induced anxiety
Human reactions to stress can range from nonchalance to crippling changes to mood and emotionality. Understanding the neural underpinnings of this individual variation is of critical importance to public health; however, the basis for differential susceptibility to stress remains poorly understood. Recently, the oligodendrocyte (the myelin-producing cell of the central nervous system) has been increasingly implicated in stress, plasticity, and mood and anxiety disorders. Furthermore, previous work from our lab has found that stress increases the production of oligodendrocytes in the hippocampus of rats. Whether changes to these glial cells are merely a secondary consequence of neural changes or whether they are a contributing factor to the outcomes of stress remains largely unknown. In the present studies, we investigated the role of these glial cells as both predictive and causative factors to stress-induced behavior. In Chapter 2, we describe how oligodendrocytes and myelin in the hippocampus correspond to long-term changes in anxiety-like behavior in an animal model of severe stress. While Chapter 2 focuses on males, Chapter 3 expands this work to females, and we discuss the differences between males and females in their responses to acute, severe stress. Together, these studies contribute to the understanding of differential susceptibility to stress and may provide new avenues for biomarkers and therapies.