Activity of dorsal spinocerebellar tract neurones in the thoracic spinal cord in relation to respiratory movement.

The discharges of 22 antidromically identified dorsal spinocerebellar tract (DSCT) neurones, whose activity was modulated in phase with the spontaneous respiratory cycle, were recorded in the lower thoracic segments of anaesthetized cats. Out of them, 16 neurones increased in their firing rate during the inspiratory phase and 6 during the expiratory phase. When the animal was paralysed and artificially ventilated, rhythmic activity of DSCT neurones was locked to the respiratory pump cycle. Once the artificial ventilation was stopped, no modulation was found even though rhythmic activity of the phrenic nerve discharges still remained. The same results were obtained in vagotomized cats. These results indicate that some thoracic DSCT neurones convey information of peripheral events in the chest wall during respiratory movement.