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Biomedical subjects

P Laget

Publications and source records attributed to P Laget.

At least 37 records · Page 2Linked to original sources
PubMed1980

[Electrocorticograms and the histochemical effects in the rat accompanying the reactivation of cholinesterases after the effects of an organophosphorus inhibitor].

The administration of paraoxon, an organophosphate inhibitor of cholinesterases, elicits theta rhythms, fast rhythms and paroxystical alterations on the electrocorticogram of the Rat. The disappearance of these abnormalities of the cortical activity after administration of aromatic oximes seems to be in good correlation with the restoration of cerebral cholinesterase activity revealed by histochemical method.

Animals↗
PubMed1979

Inhibition of (Na+ + K+)-ATPase by ouabain: involvement of calcium and membrane proteins.

Treatment of plasma membrane isolated from murine plasmocytoma MOPC 173 with an EDTA-containing buffer resulted in a 300-fold increase in sensitivity of (Na+ + K+)-stimulated Mg2+-ATPase to ouabain. This phenomenon was associated with the solubilization by EDTA of phospholipid free proteins (approx. 30 000-34 000 daltons) from the cytoplasmic face of the plasma membrane and with removal of about 90% of the membrane bound Ca2+. The recovery of the original resistance to ouabain required specifically Ca2+ and was associated with a binding of the solubilized proteins to the membrane.

Animals↗
PubMed1979

[Activities evoked in different strain structures by stimulation of the contralateral tectum in the chick].

In the chick, as soon as hatching, the responses recorded in various areas in the "accessorius hyperstriatum" (Wulst) seem to be very localized in relation with the stimulated region of the contralateral tectum. Very similar results are obtained within the other striate structures. These observations suggest in first part, that the tectal efferents project very diffusely to various striate structures and, in other part, that it exists in these a rather precise tectotopy and a columnar organisation. These results appear very constant during the first month of the hatching.

Animals↗
PubMed1977

[Study of the cortical field potentials produced by weak light stimulation in adult rabbits].

On a chronic preparation of an adult Rabbit, the cortical visual evoked response, produced by a weak luminous stimulation activating only the scotopic system is characterized by the suppression of the early surface-positive phase and by a lengthening of the latencies of the following deflection. The profile of the fields of potential corresponding to the various defletions in relation to the depth, has been investigated.

Animals↗
PubMed1976

[Maturation of somesthetic evoked potentials in man].

Somaesthetic evoked potentials (SEPs) have been recorded on the parietal scalp of 375 normal and awake children to brief electrical stimulation (0.5 msec) applied to the contralateral median nerve at the wrist. Each SEP was obtained by summation of the responses to 150 stimuli delivered at a frequency of 1/sec. The population studied has been divided in five age groups, each one corresponding to a recognizable stage of maturation of the responses.

Adolescent↗
PubMed1976

Relationship between changes in somesthetic evoked responses and electroencephalographic findings in the child with hemiplegia.

The results of somesthetic evoked response (SER) and electroencephalogram (EEG) records in 43 children with hemiplegic cerebral palsy have been compared. In all children there was a positive correlation between the SER changes and the affected side of the body. In 12 children the SER of the "damaged" hemisphere disappeared; in 31 children it was less than the response of the "healthy" hemisphere. On the other hand, a positive correlation between the EEG changes and the affected side was found in only 16 of the patients, and there was a dubious correlation in three cases. It is concluded that SER data are more accurate and reliable than EEG results. Moreover, SER findings allow cerebral damage to be suspected earlier than the EEG results and therefore are of greater prognostic value.

Adolescent↗
PubMed1976

[Study of the threshold dose of penicillin which induces an epileptogenic focus during ontogenesis in the rabbit].

A local application on the cortex surface of a very small drop of Ringer solution containing Penicillin was performed to establish the threshold dose required to elicit and epileptogenic focus and consequently the occuring latency of it. Threshold doses are small (20 - 60 International Units) and show a significant decrease during the maturation of the C.N.S. On the other hand latencies, whatever the animal's age, decrease fairly. The results are confronted to the various supposed modes of action of penicillin, modes which involve a dysfonctioning of the Na+ and K+ ionic pump.

Age Factors↗
PubMed1976

[Development of tectum-striatum and striatum-tectum connections in the chick].

In the chick, polyphasic evoked responses displaying a first negative component have been registered in the superficial part of the "Wulst" after stimulation in the depth of the contra or ipsilateral optic tectum, as early as the first hours following hatching. Moreover, responses on the surface of the tectum have been elicited by contra or ipsilateral stimulation of the Wulst. Latencies of both responses decrease markedly with increasing age but, in the whole, ipsilateral responses remain more latent than contralateral responses.

Age Factors↗
PubMed1975

[Unit activities of the salmon Salmo salar preoptic nucleus in Parr, Parr-Smolt and Smolt stadia].

UNLABELLED: The olfactory and gustatory stimulations with NaCl (10(-5)-10(-2) M/1) bring about certain typical modifications of the preoptic cells activity in the case of "Parr" and "Parr smolt". The "on" or "off" or "on and off" effects are very marked. Unlike the "Smolt" stage is accompanied by an important decrease of the preoptic cells activity, sometimes until complete silence of the nucleus. DATA ANALYSIS: sequential analysis and statistical analysis. The activities recorded on a magnetic tape are feld to a mini computer.

Animals↗