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Biomedical subjects

M Aoki

Publications and source records attributed to M Aoki.

At least 829 records · Page 46Linked to original sources
PubMed1977

Functional properties of peripheral sensory units in hairy skin of a cat's forelimb.

The properties of peripheral cutaneous units in the hairy skin of cat's forelimb were studied by single-fiber recordings with tungsten microelectrodes. The response properties and receptive field (RFs) of total 193 units in superficial branch of radial nerve (SRN) were studied. The SRN sample included the following five major types of mechanoreceptive units; two types of low-threshold units (type I and II, slowly adapting), two types of hair units (G and D, rapidly adapting) and field units (F, responding principally to slow skin movement). Afferent conduction velocities of these units ranged from 9.0 to 56.0 m/sec. D hair fibers conducted much slower than other types of afferents and their conduction velocities were between 9.0 and 23.3 m/sec. Most of the smaller RFs of G, D and F units were found in the paw and digits. The disto-proximal increase of the mean size of RFs was marked in D hair units. The distributions of the RFs of simultaneously recorded paired units, which were supposed to be adjacent fibers, were examined. Among 23 paired units, more than half of them were homonymous combinations of unit types and there were no marked prevalence of particular types in heteronymous combinations. The RFs of paired units were close to each other, but showed little overlaps and some were separated by up to several cm over the skin surface. Some functional properties of cutaneous afferents from the forelimb were discussed.

Animals↗
PubMed1977

Ossifying fibroma of the occipital bone.

A rare ossifying fibroma in the occipital bone is described, and the available literature reviewed. The rapid growth seen in this case was remarkable and led us to believe this was a malignant osteogenic tumor. Full knowledge and the correct diagnosis of ossifying fibroma should have prevented an unnecessarily extensive operation for this benign lesion.

Child↗
PubMed1976

Exaggeration of knee-jerk following spinal hemisection in monkeys.

In 18 monkeys ipsilateral flaccid hemiplegia of the hind-limb was produced by spinal cord hemisection at T8. As a result of systematic observations of various phenomena subsequent to the hemisection for several months, it was found that an ipsilateral marked exaggeration of the knee-jerk gradually developed in 2--3 weeks after the infliction, along with slight atrophy of the hind-limb muscles on the same side. The exaggeration reached a maximum in about 6 weeks and persisted thereafter for several months until the final experiments. The exaggeration of knee-jerk was confirmed by measuring quantitatively photographed trajectories of a small lamp attached to the malleolus, a specially devised hammer being used. The trajectories showed larger amplitudes, shorter rise times and lower thresholds on the hemisected side. Achilles tendon reflex was also observed to be hyperactive. However, there was no evidence of other pathological phenomena such as clonus or Babinski's sign in the present experiment. It was noted that total spinal cord transection one segment below the hemisected site did not abolish the exaggeration of knee-jerk. Another noticeable finding was that quadriceps afferent volleys picked up from the L6 dorsal root following tendon taps were smaller on the hemisected side, in spite of the fact that distinct augmented reflex potentials were observed in the ipsilateral L6 ventral root. These results strongly suggest that the exaggeration of knee-jerk was not induced by a release from tonic supraspinal inhibition nor by augmented quadriceps afferent volleys, but by some neural mechanisms which developed gradually within the lumbo-sacral segments below the hemisected site.

Animals↗