Spinal respiratory motoneurons and interneurons.

Maintenance of life among higher vertebrates depends on permanent, rhythmic and coordinated activity of respiratory muscles. Fundamental to our understanding of breathing is an appreciation for the neural components involved in the generation, maintenance and modulation of respiratory rhythm. Multidisciplinary studies have revealed important perspectives about the spinal and supraspinal components contributing to breathing, but a complete understanding of respiratory pathways and their interconnectivity remains unknown. Definition of these pathways is essential for understanding how respiratory processes may be affected by injury or disease. The present review highlights our current understanding of the distribution of spinal motoneurons and interneurons involved in mammalian respiratory activity and how they are affected by injury or disease in the central nervous system.