Some Properties of Pyramidal Neurones in Motor Cortex With Particular Reference to Sensory Stimulation

Psychophysics and neurophysiology.

“…For example, large pyramidal cells in cerebral motor cortex send axons into the pyramidal tracts. Electrical stimulation of the medullary pyramids antidromically fires such cells [56]. Further work may clarify the extent of sampling biases in microelectrodes.…”

Topographic Relationship Between the Receptive Fields of Neurons in the Motor Cortex and the Movements Elicited by Focal Stimulation in Freely Moving Cats

“…Evidence that somatic afferents distribute to the"motor cortex"as well as the"sensory"cortex has been demonstrated by the evoked potential method both in the monkey25, 45),and in the cat27,32).This afferent projection has been related to the motor activity by ADRIAN and MORUZZI1)who found that the pyramidal tract discharge was activated by peripheral sensory stimulation. Recently,cortical efferent neurons identified by antidromic pyramidal stimulation(PT-cells)were found to be activated by cutaneous nerve stimulation2, 21,34). Subsequently,BROOKS et al 5,6)activated PT-cells in the motor cortex by natural stimulation and plotted their receptive fields.These investigations indicated a kind of reflex activation of pyramidal neurons by somatic afferents.…”

Cerebellar influence on pyramidal‐tract neurones

“…Since this cerebellocortical system appears to involve the reticular formation and, perhaps, many thalamic nuclei, one might expect rather complex effects on the activity of cortical neurones. Conditioning stimulation via a sensory (skin) nerve may either facilitate or suppress the antidromic activation of pyramidal tract neurones during conditioning-testing intervals of 10-25 msec (Li, 1959). Facilitatory effects on cortical sensory neurones and inhibitory effects on neurones in the motor cortex have been demonstrated following the stimulation of centromedian and ventralis lateralis nuclei, respectively (Li, 1956a, b), and both facilitatory and depressive alterations in the magnitude of the cortically-evoked pyramidal tract discharge follow repetitive stimulation of thalamic relay nuclei (Brookhart & Zanchetti, 1956).…”