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Biomedical subjects

G Lelord

Publications and source records attributed to G Lelord.

At least 91 records · Page 5Linked to original sources
PubMed1978

[Autism, inhibition, electrophysiology and biochemistry].

The term "inhibition" is not usually employed in the psychopathology of schizophrenia. However, in defining some neuroleptics' action, the work "desinhibition" is currently used and Pavlov explained the main features of the schizofrenic syndrome through a transmarginal inhibition mechanism. The purpose of this study is to investigate if an inhibition process underlies some phenomena shown up by the evoked potentials (EPs) method. Usually, a lower EPs' amplitude is seen in schizophrenic patients than in normals. This phenomenon is displayed by: -- simple stimuli EPs: they show weak amplitude and high variability; -- double-shock EPs: they have a long recovery-cycle; -- conditioned EPs: their amplitude is minimally augmented by coupling the conditioned and the unconditioned stimulus; -- EPs in experiments with increasing-intensity stimuli: their amplitude decreases as stimulation intensity increases. Some of these concurrent data could indicate a transmarginal inhibition, particularly the lengthening of the recovery cycle and the amplitude-reduction phenomenon. Although these are preliminary results, nevertheless some relationships emerge between clemical, electrophysiological and biochemical data.

Brain Chemistry↗
PubMed1978

[Modifications in urinary homovanillic acid after ingestion of vitamin B6; functional study in autistic children (author's transl)].

Basing their study on the investigations which led to the dopaminergic theory of the psychoses, the authors studied homovanillic acid (principal derivative from dopamine) levels in the urines of 37 autistic children, and 11 normal children acting as controls. The favourable action of vitamin B6 on autism, reported by anglosaxon authors, was confirmed in 15 of the children. Furthermore, vitamin B6 reduces homovanillic acid levels in 33 autistic chilren and increases them in all the control group children.

Autistic Disorder↗
PubMed1976

[Conditioning of slow electrocortical activity evoked by sensory stimulation and by a reflex movement in man].

Slow cerebral waves are recorded from 10 adults during an experiment consisting of the application of isolated or coupled sensorial stimulations, the weak sound occuring 880 msec prior to the strong light when coupled. Prior to coupling, the stimulations evoke on the vertex generally negative slow waves which would indicate an orientation reaction. After coupling, the responses to sound become constantly negative and are considered as waves described as "negative contingent variations". To the contrary, responses to light are inverted and become constantly positive. Such a phenomenon equally observed during experiments consisting of sound coupled to a reflex movement recalls the resolution of the negative contingent variation, the decision wave and the motor potentiel that accompanies the execution of voluntary movement, however here, it is produced during conditioning which does not require active motor participation by the subject. These results demonstrate that the simple coupling of two stimulations following the protocol developed by Pavlov provokes in man a complex collection of responses containing a motor component analogous to that which one observes in more elaborate experiments destined to prove the anticipation of the decision.

Achilles Tendon↗