[Reaction of the respiratory musculature to electrical stimulation of the corticospinal tract].

Stimulation of the corticospinal tract (CST) at the mid medullary level in anaesthetized cats evoked contraction of the diaphragm (D) with a perfectly reciprocal inhibition of the abdominal oblique muscles (AOM). On the contrary, its stimulation in the pyramidal decussation caused inhibition of the D and contraction of the AOM. Possible reasons of the opposite effects of stimulation of the CST at different bulbar levels are discussed.