[Changes in spino-bulbo-spinal reflexes during the respiratory cycle in cats]

In cats anesthetized by chloralose the characteristics of a somaesthetic startle reaction (spino-bulbo-spinal reflex) essentially change during respiration; the magnitude of the responses recorded in the internal and external intercostal nerves as well as flexor hindlimb nerves was regularly less during the inspiration phase than during the expiration one. The phase changes were due to respiratory modulation of spino-bulbo-spinal transmission at the supraspinal level (brain stem reticular formation) and were determined mainly by its depression during inspiration.