Antidromic responses evoked in the central end of the phrenic nerve by stimulation of the ipsilateral dorsal column in the cat]

In 15 adult cats under nembutal anaesthesia the dorsal columns have been stimulated at the level of the first and the second cervical segments. Under these conditions antidromically evoked responses appear both on the ipsilateral radial and phrenic nerves. Some of the afferent phrenic fibres thus activated may be related to the diaphragm muscle receptors. In some experiments a group of thin fibres (conduction velocity comprised between 16-20 m/sec) were also activated.