[Organization of cortico-reticulo-spinal connections in the cat]

Time characteristics of the monosynaptic EPSP evoked by stimulation of the motor cortex in reticulospinal neurons were studied in detail. Negative correlation was revealed between latency duration of EPSP and conduction velocity of the corticobulbar fibres and positive correlation between such characteristics and conduction velocity of axons. Reticulospinal neurons with conduction velocity from 10.8 to 65.0 m/s were activated by fast and slow corticobulbar fibres, but neurons with conduction velocity from 65.0 to 155 m/s were activated only by slow ones. A functional role of different cortico-reticulo-spinal connections is discussed.