Distribution and properties of commissural and other neurons in cat sensorimotor cortex (original) (raw)
1975, The Journal of Comparative Neurology
Commissural, cortico-cortical and corticocaudate neurons have been investigated in the primary sensorimotor cortex of the cat, using antidromic stimulation techniques, and histological identification of recording sites. These neurons are to be found in all cortical laminae except the first; commissural and cortico-cortical neumns were found to be commonest in laminae 111 and VI, whilst corticocaudate neurons were most abundant on the border between laminae I11 and V, in motor areas. In sensory areas topographically identified as representing distal parts of limbs, commissural neurons are very rare, confirming neuroanatomical studies on the origin and termination of callosal fibres. The intracerebral neuronal Projections investigated in this study had slow conduction velocities (less than 1 m/sec, up to about 10 m/sec). It was found that projections from area 6, whether commissural, cortico-caudate, or corticopeduncular have slower conduction velocities than their counterparts from area 4. It is suggested that this is related to the type of motor control in which these two areas are involved (slowly-responding postural movements, as opposed to more rapid distal limb movements). No neurons were found which had both commissural (or corticocortical), and cortico-fugal projections.
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