[Effectivess of synaptic influences of the ascending tracts of different spinal cord funiculi on reticulospinal neurons in cats].

Extracellular recording of the responses of the reticulospinal neurons evoked by stimulation of the dorsal, dorsolateral, ventral and ventrolateral spinal funiculi were performed in cats under chloralose anesthesia. It is found that dorsal funiculi of the spinal cord are an effective source of ascending influences on the reticulospinal neurons. Correlation of synaptic responses of the reticulospinal neurons with antidromatic responses in the peripheral nerves set up by stimulation of the dorsal funiculi shows that the former can be evoked by low threshold muscle (groups I and II) and cutaneous (group II) afferent fibres. The role of the ascending tracts in the transmission of the spino-bulbo-spinal activity is discussed.