Functional analyses of molecularly-defined spinal interneurons in regulating motor activity

Locomotor movements, such as walking, running and swimming, come to us so naturally that most people may not realize that such activities are very complex and require a high degree of coordination of many limb and body muscles involved. The neurons that control the muscles that generate locomotion are located in the spinal cord. Motor neurons are the commanders that directly innervate different muscles. The activity of these motor neurons in turn is strictly and precisely controlled and regulated by interneuron circuits mainly located in the ventral spinal cord. Up until very recent research, the components and structure of the neural circuits that ultimately control locomotion have remained largely unknown. New discoveries of the molecular codes of different neurons in the spinal cord have allowed us to identify several groups of interneuons there and have also provided us with powerful genetic and molecular tools to manipulate the activity of these neurons. In my laboratory, we will take advantage of these breakthroughs and combine anatomical, behavioral, electrophysiological and optical recording technologies to study the functional roles that different spinal interneurons play in the locomotor circuits. This will allow us to better understand how they regulate the motor neuron activity that generates a balanced and stable gait. Such knowledge will be the foundation for further explanation of the roles that different spinal neurons play under pathological conditions, such as spinal cord injury and degenerative diseases, and this in turn will potentially enable us to find new treatments for these conditions.