Phasic control of the transmission in the excitatory and inhibitory reflex pathways from cutaneous afferents to α-motoneurones during fictive locomotion in cats

Abstract

In high spinal paralyzed cats the effect of cutaneous nerve stimulation on lumbar motoneurons was investigated during fictive locomotion. EPSPs evoked from the cutaneous afferents were generally larger during the active phase of the motoneurones, while IPSPs tended to increase during the reciprocal phase. In some cases EPSPs occurred during the active phase, while IPSPs dominated during the reciprocal phase. Apparently, the transmission in the excitatory and inhibitory segmental reflex pathways from cutaneous afferents to α-motoneurones depends on the phase of the step cycle, but there is no general phase dependent alternating switching between these two pathways.