Abstract: Adult-born oligodendrocytes are continuously produced in the brains of rodents. The functional role of these cells has been linked to the motor-related activities of healthy animals and is vital for acquiring new motor skills. However, the relationship between these cells and the control of motor-related activities has not been investigated in pathological conditions. Therefore, the aim of this study is to investigate the role of oligodendrocytes in depression-related motor deficits and the effects of training. Psychomotor retardation is a key symptom of depression. Consistent with the impairments observed in rodent motor performance, the proliferation and activation of adult-born oligodendrocytes are altered in a corticosterone-induced stress paradigm. Therapeutic rotarod training can alleviate these symptoms by reversing the aforementioned changes. Notably, these alterations are particularly pronounced in layer I of the motor cortex. Thus, this study provides evidence of the potential functional involvement of adult-born oligodendrocytes in the motor impairments observed in the depressed animals. Additionally, it offers preliminary results for further investigation into layer I of the motor cortex in relation to these pathological conditions.

Key words: corticosterone-induced stress, exercise, major depressive disorder, motor cortex, motor deficits, motor training, myelination, oligodendrocyte lineage cells, oligodendrocyte precursor cells, psychomotor retardation