Neuronal organization of the central respiratory mechanisms in the brain stem of the cat.

In order to obtain basic evidence on the neuronal organization and localization of the central respiratory mechanism in the brain stem of the cat, the following experiments were undertaken: reexamination of the physiological meaning of apneusis and the gasp; differences in stability of spontaneous burst activity of respiratory neurons in the brain stem reticular formation; changes of spontaneous firing pattern of bulbar respiratory neurons in the isolated brain stem of the cat; changes of firing pattern of a pontine and a bulbar respiratory neuron during continuous recording of both unitary activities after brain stem transection at the pontomedullary junction; responses of respiratory neurons to electrical stimulation of the spinal cord; responses of respiratory neurons to electrical stimulation of the central cut end of the vagus nerve; effects of pentobarbitone on unitary activity of pontine and bulbar respiratory neurons. Based on the experimental result a preliminary scheme of a neuronal network of the central respiratory mechanism consisting of four subsystems of respiratory neurons: a primary neuron system; a satellite neuron system; an input neuron system; an output neuron system.