Central chemosensitivity is critically important to maintain homeostasis. e have successfully applied a voltage-imaging technique to medullary slice and isolated brainstem-spinal cord preparations and analyzed chemosensitive neuronal network organization in the rat ventral medulla. Our results indicate that neurons in the superficial ventral medullary chemosensitive regions and deeply located medullary respiratory neuronal network are interconnected. We propose a neuronal network organization model for central chemoreceptors.