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Biomedical subjects

M Antal

Publications and source records attributed to M Antal.

At least 109 records · Page 6Linked to original sources
PubMed1984

Segregation of muscle and cutaneous afferent fibre terminals in the brachial spinal cord of the frog.

Separate filling with cobalt of individual nerves of the arm revealed that cutaneous afferent fibres terminate in an oval-shaped area at the superficial part of the dorsal horn, while muscle afferent fibres terminate in a triangle-shaped area lying deeper in the gray substance of the frog spinal cord. In a few cases, flexor muscle afferents also emit a small number of short collaterals to the ventral part of the oval-shaped area. In the medulla, cuaneous afferents project onto the dorsal part and muscle afferents onto the ventral part of the cuneate nucleus. Muscle afferents only terminate in the cerebellum.

Afferent Pathways↗
PubMed1984

Termination areas of corticobulbar and corticospinal fibres in the rat.

Solution of the cobaltic lysine complex compound injected into the bulbar pyramid was taken up by pyramidal tract (PT) fibres and intraaxonally transported as far rostral as the internal capsule, and as far caudal as segment C4 of the spinal cord. With sulfide-precipitation of the cobalt and silver-intensification of the CoS, terminal branches of corticobulbar and corticospinal fibres could be shown in the following structures: In the pons the medial, ventral and the medial part of the lateral pontine nuclei are supplied with collaterals of PT fibres. The medial pontine nucleus receives contralateral PT fibres as well. The nucleus raphe magnus receives PT fibre collaterals from both sides. In the reticular formation contralateral fibres terminate in n. reticularis pontis caudalis, n. gigantocellularis, n. paramedianus, n. reticularis ventralis and dorsalis. Ipsilateral fibers terminate in the n. gigantocellularis and n. reticularis ventralis. The inferior olive receives both ipsilateral and contralateral PT fibres. All parts of the central gray substance are supplied by ipsi-and contralateral fibres which emerge from the PT at the level of the pyramidal decussation. The caudal nucleus of the spinal nucleus of the trigeminus receives a strong bundle of crossing PT fibres which terminate in the subnucleus magnocellularis. The dorsal column nuclei are virtually outlined by the numerous terminals of PT fibres. An oval area at ventrolateral aspect of the cuneate nucleus is innervated by PT fibres. The neurones of this area send their axons to the dorsal white column. In the spinal cord PT fibre terminals delineate four areas of termination. The first is the internal basilar nucleus which is the most richly supplied. The second lies lateral and ventral to this nucleus including segments of laminae V, VI, and VII. The third area extends into the ventral horn including a small zone of the ventral part of lamina VII. Thin PT fibre collaterals may establish here direct contacts with motoneurone dendrites. The fourth area includes laminae III and IV and receives individual terminal formations of thicker PT fibres. Findings which corroborate and which extend previous results are discussed. A few notes are made on the functional significance of some of these fibre connections.

Animals↗
PubMed1982

The termination of cutaneous nerves in the dorsal horn of the spinal cord in normal and in skin-rotated frogs.

Following transganglionic transport of cobaltic lysine applied to the cut end of cutaneous nerves, the central terminal arbours were filled to such an extent that it was possible to visualize the dermatomal projection upon the dorsal horn in unoperated and in skin-rotated frogs. Sensory nerves of the trunk skin terminate in an oval-shaped area which probably corresponds to laminae 1-3 (or 1-4) in the mammalian spinal cord. One type of terminating collateral had a restricted terminal field either in the medial, or in the lateral, part of the oval-shaped area. Another type ended with a large terminal arbour covering almost the total extent of the oval shaped area. These terminal arbours were found for both the dorsal and the ventral cutaneous nerves. Dorsal cutaneous nerves projected preferentially to the lateral part, while ventral cutaneous nerves projected to the medial part, but both nerves sent a significant contingent of collaterals to the whole extent of the oval-shaped area. A rearrangement of the central projection patterns of the dorsal cutaneous nerves, consistently mediating misdirected responses, was not observed in skin-rotated frogs. Collaterals of trunk skin nerves terminated exclusively in the thoracic segments; they did not enter the limb-innervating (brachial and lumbosacral) segments of the spinal cord. The results corroborate the crossed pattern of sensory input in the dermatomal projection. The large, extensively overlapping, areas of termination of individual skin nerves suggest that wiping responses mediated by these nerves should be regarded as complex behaviour released from a preprogrammed centre rather than a reflex arc in which the presence specificity would be determined by wiring specificity.

Animals↗
PubMed1982

Effect of dietary protein and lipid on the activity of hepatic mixed-function oxidase system in young and adult rats.

Effects of marginal or normal casein diets with different sunflower oil contents were tested on the hepatic mixed-function oxidase system in young and adult male rats. The weight gain and the activity of aminopyrine demethylase, aniline hydroxylase and the content of cytochrome P-450 was decreased only in young rats fed 10% casein and 10% oil containing diets. Both in young and adult animals, independently of casein consumption, the activity of MFO with the exception of cytochrome P-450 in adult rats fed 20% casein was significantly higher when the level of dietary sunflower oil was shifted from 10 to 30%.

Aging↗
PubMed1982

[Lafora bodies in the retina of various animals].

Lafora's bodies, formerly described in the retina in humans affected with familial myoclonic epilepsy--or Lafora's disease--and in dogs, were found not only in retinas of clinically healthy monkeys (macacus rhesus), but also in those of the healthy cat and dog. Lafora's bodies are not there fore characteristic of the specific disease.

Aging↗
PubMed1981

Etomidate induced retinal changes.

The author examined the effect of etomidate-anaesthesia of one hour duration on the ultrastructure of the retina in animal experiments. Immediately after the exposure only the Müller's cells were moderately damaged. One day following the narcosis more serious pathological changes developed in the external nuclear layer which were partly irreversible. The changes found in the internal nuclear layer were less serious. The structure of the glial cells also altered. In the specimens taken 48 h following the anaesthesia the pathological changes of the neurons regressed to some degree, the Müller's cells reorganised and masses of glycogen accumulated in them. Further studies are needed to explain the eventual retinal toxic effect of this agent.

Animals↗
PubMed1981

Studies on prostaglandin F2 alpha formation caused by pentametylenetetrazol-induced convulsions in rat brain.

Prostaglandin F2 alpha formation caused by pentametylenetetrazol convulsions was studied as a function of the duration, the doses of the convulsant and the intensity of the seizures. It was shown by the statistical analysis of the results in the case of clonic convulsions that the amount of synthetized PGF2 alpha did not depend on the doses of convulsant, while close relation existed between the duration and the PGF2 alpha production. At the same time, during tonic convulsions lasting longer than 50 sec, no more increase in the PGF2 alpha content of the brain was observed. An experimental model is suggested to study in vivo the mechanisms regulating the brain's prostaglandin biosynthesis. Pretreatment of the animals with reserpine did not affect the rate of convulsion-induced PGF2 alpha-formation.

Animals↗
PubMed1981

Effect of dietary carbohydrates and ethanol on the activity of microsomal drug-metabolizing enzymes in rat liver.

Effects of fructose, starch, lactose plus starch and ethanol on the drug-metabolizing enzyme system of the liver were analyzed in rats fed fructose, starch or lactose plus starch diets for 21 days. The activity of aminopyrine demethylase and aniline hydroxylase and the level of cytochrome P-450 increased significantly in rats fed lactose plus starch compared to the groups fed fructose or starch diets. The activity of aniline hydroxylase increased as a result of ethanol, independent of the nature of the carbohydrate but in this case the highest activity was also found in the livers of rats previously fed a lactose plus starch diet.

Aminopyrine N-Demethylase↗