Post‐natal development of the cerebello‐cerebral projection in kittens.

Abstract

SUMMARY1. Post-natal development of the cerebello-cerebral response was investigated in 126 kittens from birth to 142 days of age by analysis of laminar field potentials in the cerebral cortex; the thalamocortical projection mediating the cerebello-cerebral response was examined on four new-born and three one-month-old kittens by means of anterograde axonal transport of horseradish peroxidase.2. A marked response was evoked in the frontal motor cortex from birth and an appreciable response could be evoked in the parietal association cortex at 2 days after birth. The latency of response in the frontal cortex decreased sharply from birth till 3 weeks of age whereas that in the parietal cortex remained almost unchanged until 2 weeks of age. Maturation of the cerebello-cerebral projection, in every respect, proceeds earlier in the frontal cortex than in the parietal cortex.3. The cerebello-cerebral response in kittens at any age, like in adult cats, consisted of two types of elementary responses: one which is characterized by a surface positive-depth negative (s.p.-d.n.) wave and the other which is characterized by a surface negative-depth positive (s.n.-d.p.) wave. The response in the frontal cortex was a sequential occurrence of the two waves while the response in the parietal cortex was a pure form of the s.n.-d.p. wave. 4. Two types of thalamocortical projections corresponding to the two types of elementary responses were revealed: one is the projection mainly onto layer I which appears to mediate the s.n.-d.p. wave and the other is the projection mainly onto layer III which appears to mediate the s.p.-d.n. wave.5. Development of the cerebello-cerebral response and changes in the terminal distribution of the thalamocortical projection during maturation are consistent with the principle of ontogenesis of the mammalian neocortical organization, i.e. ascending sequential maturation.

Post‐natal development of the retinal and cerebellar projections onto the lateral suprasylvian area in the cat.

“…In both cortical areas, the labelled terminals were always distributed mostly in layer I, with a few labelled terminals in the other cortical layers. The finding in the crown was the same as reported previously (Kawaguchi et al 1983b).…”

Input-Output Organization of the Ventrolateral Nucleus of the Thalamus

“…Sasaki et al [24] suggested from the electrophysiological study that there should be superficial and deep TC projections. These dual projections were demonstrated anatomically [25,26]. More recently, Jinnai et al [27] reported that TC neurons in the VA-VL complex which receive in puts from the globus pallidus, but not from the cerebellar nuclei, pro ject to layer I of the anterior sigmoid gyrus in the cat.…”

Post‐natal development of pyramidal tract neurones in kittens.

“…nucleus and the cerebellar nuclei have different synaptic effects on fast and slow p.t.n.s (Yoshida, Yajima & Uno, 1966;Takahashi, Kubota & Uno, 1967;Deschenes, Landry & Clereq, 1982;Noda, Yamamoto, Miyata & Nishimura, 1983;Noda & Yamamoto, 1984). We tried to check whether such differences in synaptic activation are present in the immature cerebral cortex, where the general feature of dendrites and axon collaterals of p.t.n.s as well as thalamic afferents are already established (Purpura, Shofer & Scarff, 1965;Wise, Hendry & Jones, 1977;Kawaguchi et al 1983). Fig.…”

“…Concerning the post-natal development of the pyramidal tract, there have been reports of electrophysiological studies on myelination of the pyramidal tract in cats (Huttenlocher, 1970;Purpura et al 1964) and rabbits (Conway, Wright & Bradley, 1969), but no reports on morphological and functional aspects of differentiation between fast and slow p.t.n.s using intracellular HRP staining. Kawaguchi, Samejima & Yamamoto (1983) have described the post-natal development of the cerebello-cerebral projection in kittens. The afferent systems into the motor cortex through the thalamic ventral anterior and lateral nuclei (v.a.…”