chapter Introduction -- chapter 1 Optical and Genetic Approaches toward Understanding Spinal Circuits -- chapter 2 Spinal Motoneurons: Synaptic Inputs and Receptor Organization -- chapter 3 5-HT Receptors and the Neuromodulatory Control of Spinal Cord Function -- chapter 4 Advances in Measuring Active Dendritic Currents in Spinal Motoneurons in Vivo -- chapter 5 Investigating the Synaptic Control of Human Motoneurons: New Techniques, Analyses, and Insights from Animal Models -- chapter 6 The Use of Correlational Methods to Investigate the Organization of Spinal Networks for Pattern Generation -- chapter 7 Sensory–Motor Experience during the Development of Motility in Chick Embryos -- chapter 8 Transformation of Descending Commands into Muscle Activity by Spinal Interneurons in Behaving Primates -- chapter 9 Muscle Afferent Feedback during Human Walking -- chapter 10 Canine Motor Neuron Disease: A View from the Motor Unit -- chapter 11 Structural Plasticity of Motoneuron Dendrites Caused by Axotomy -- chapter 12 How Does Nerve Injury Strengthen Ia-Motoneuron Synapses? -- chapter 13 The Organization of Distributed Proprioceptive Feedback in the Chronic Spinal Cat.