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Biomedical subjects

N Kudo

Publications and source records attributed to N Kudo.

At least 163 records · Page 9Linked to original sources
PubMed1975

The vestibulospinal tract: crossed and uncrossed effects on hindlimb motoneurones in the cat.

Effects produced by stimulation of Deiters' nucleus on contralateral hindlimb motoneurones were investigated in the cat with intracellular and monosynaptic reflex recording. Polysynaptic PSPs were evoked in all species of motoneurone examined. The minimal synaptic linkage was found to be disynaptic in the excitatory path and prisynaptic in the inhibitory path. Experiments with various lesions to the spinal funiculus and those with mapping of the stimulated sites in the brain stem showed that the effects were evoked almost exclusively via the lateral vestibulospinal tract of the stimulated side. The crossed effects were excitatory in extensor motoneurones of all species studied except for hip extensors (ABSm) in which EPSPs and/or IPSPs were evoked. The effects on flexors, by contrast, were not simple and consisted of EPSPs, IPSPs or a mixture of both. The difference in effects depended, though not entirely, on the species of motor nucleus. Between the excitatory and inhibitory effects on knee flexor (PBSt) motoneurones the former predominated under chloralose and the latter under pentobarbital anaesthesia. By recording PSPs evoked from the two vestibulospinal tracts in the same motoneurone, the convergence pattern and the magnitude of effects from the two tracts were studied. The interneuronal organization of the crossed vestibulo-motoneuronel pathway and its functional significance are discussed.

Animals↗
PubMed1975

Effect of colchicine on the secretion of matrices of dentine and enamel in the rat incisor: an autoradiographic study using [3H]-proline.

Effects of colchicine on the incorporation of [3H]-proline into odontoblasts and ameloblasts at various development stages and on the secretion of the radioactive materials from these cells into dentinal and enamel matrices were studied autoradiographically, at 2,4,8 and 24 h after the injection of colchicine. In young functional and functional odontoblasts and ameloblasts, the number of autoradiographic silver grains over the cells increased while those over the matrices decreased 2,4, and 8 h after the injection of colchicine. However, the total number of grains over the cells and matrices were fairly uniform in all stages of cell development at all times after the injection of the drug. It is suggested that the drug does not appreciably affect the incorporation of [3H]-proline or the successive synthesis of the dentinal and enamel matrices but affects the secretion of the matrices in both functional odontoblasts and ameloblasts by interfering with the structure and function of microtubules in these cells.

Ameloblasts↗