Psychophysiological and clinical value of event-related potentials in obsessive-compulsive disorder.

To investigate brain correlates of cognitive function in obsessive-compulsive disorder (OCD), event-related potentials (ERPs) were recorded in a group of thirteen unmedicated OCD patients and thirteen normal controls for verbal auditory stimuli in an oddball paradigm. The patients showed longer latencies of the N1 and P2, shorter latency of the P3, and reduced amplitude of the N2. These results suggest that OCDs stress the speed of task-dependent processes (i.e., by showing shorter N2 and P3 latencies) and have impairment of task-independent ones (i.e., by showing longer N1 and P2 latencies and reduced N2 amplitude). The components were more positive in the left hemisphere in OCDs and in the right hemisphere in normal controls. Future responders to treatment had significantly reduced N2 and enhanced P3 amplitudes relative to future nonresponders. So ERPs might provide psychophysiological profiles in OCDs with clinical and pharmacological implications.

Gait analysis of myopathic children in relation to impairment level and energy cost.

The electromyographic and kinematic patterns of gait and its energy cost were studied in 12 myopathic patients who were still walking and 12 normal subjects. On the basis of significant gait variables, three distinct levels of impairment were defined in the group of myopathic subjects: early, intermediate and final. These clusterings were predicted with 95.7% accuracy by two gait variables: the stance phase duration and the heel vertical excursion. The gait patterns of each group were compared to the control group. Reduced speed and range of motion, short stride length, small foot-floor clearance, increased energy cost and lateral displacements of centre of gravity were typical and increased with the muscular weakness. The activation of soleus muscle occurred progressively earlier as did the cessation of tibialis anterior activity. In severe disorders, there was increased activity in the muscles acting on the hip and knee. When muscular dystrophy leads to more disability the myopathic patients tended to change from the normal plantigrade gait pattern to an infantile digitigrade-like pattern with a decrease of the tibialis anterior muscle work.

[Histofluorometric study of catecholamines of the external layer of median eminence in the rabbit (author's transl)]. / Histofluorométrie des catécholamines de la couche externe de l'éminence médiane hypothalamique de la lapine. Variations anatomiques et au cours de l'activation de l'axe hypothalamo-gonadique.

In order to study the role of the Biogenic Amines of the Median Eminence (M. E.) in the ovulatory neuroendocrinological reflex in the female rabbit, we analysed by semi-quantitative histofluorometry (Zeiss) the post-coïtum variations in formaldehyde induced fluorescence (Falck and Hillarp's technique) in the dopaminergic layer of the M. E. 116 female rabbits (62 control, 54 post-coïtum) were examined. In all the animals the dopaminergic layer of the M.E. displayed variations in fluorescence, both in thickness and intensity, along the antero-posterior axis and lateraly. In this respect, these results partly recovered those reported in the Rat (Lofstrom, 1976). Moreover, in half of the post-coïtum animals, from the 5 th min. up to the 30 th min, the intensity of the fluorescence was increased in the whole external layer. These results provide some evidence for a correlation between the variations in the Dopamine content of the M.E. and the involvement of the nervous mechanisms implied in the ovulatory neuroendocrinological reflex.

[Electrophysiological development under thalamic stimulation of post-traumatic persistent vegetative states. Apropos of 25 cases]. / Evolution électrophysiologique sous stimulation thalamique des états végétatifs persistants post-traumatiques. A propos de 25 observations.

We have studied the electrophysiological evolution, with the aid of long-term, quantitative E.E.G. (Holter method) and sensory evoked potentials (visual, auditory and somatosensory) on 25 severe traumatic head injury patients (initial Glasgow scale--between 3 and 5) aged from 5 to 42 years having evolved towards a persistent vegetative state and being object of a protocol of thalamic stimulation. Electrophysiological exploration was practised before placement of the stimulation, then at 2 weeks, 1 month, 2 months and finally 3 months after. The electrophysiological parameters appear to have no predictive value on the clinical evolution after stimulation. However, changes such as long-term quantitative EEG as well as evoked potentials mostly precede clinical progress when present. Cortical evoked potentials are the first to change significantly (J15) followed by long-term quantitative EEG and brain stem evoked potentials (J30); the latter improving more completely. Also the consideration of the chronobiological aspects of the recordings of the long term EEG allow the proposal of "waking targeted" stimulations at the most favorable moments of the nyctohemeral period.

Catecholamine histofluorescence in the median eminence of female rabbits activated by mating.

Mating was used in the rabbit as a physiological trigger, easily definable in time, for the activation of gonadotropic hypothalamic structures. Using the histochemical fluorescence technique of Falck and Hillarp, it has been attempted to determine whether, in relation to mating, clearly distinuishable and reproducible changes in histofluorescence occur in the tuberoinfundibular dopaminergic system in combination with hypothalamic hypophysiotropic hormone release. Between 20-30 min post-coitum an increase in DA turnover was noted in the external layer of the median eminence. The characteristics of this reaction were studied by administration of reserpine and alpha-methyl-paratyrosine. Immediately after coitus, a paradoxical fluorescence reactivation was observed in the median eminence in female rabbits in which tyrosine-hydroxylase activity was inhibited for 5 hours.

PIP: An experiment to determine whether histofluorescent changes occur in the tuberoinfundibular dopaminergic complex along with hypothalamic hypophysiotropic hormone release in relation to mating in the rabbit is presented. Reserpine was injected immediately after mating, and tyrosine hydroxylase was injected 5 hours before mating. In untreated animals, the fluorescence intensity of the catecholamines present in the periventricular area of the median hypothalamus was slightly decreased, 15-20 minutes postcoitum, although at 30 minutes the fluorescence intensity of the entire layer of the median eminence was distinctly increased. A fixed dose of reserpine resulted in a progressive decrease of fluorescence intensity with time, whereas a variable dose of reserpine administered for a fixed time resulted in an increase of fluorescence activity with increased doses. Coitus, performed 5 hours after tyrosine hydroxylase injection, was a potent reactivator of median eminence fluorescence. This paradoxical reaction was highly conspicuous 5 minutes after coitus, but decreased thereafter. Some possible explanatory hypotheses for the observed actions are discussed.

[Histochemical fluorescence study of aminergic cells throughout the central nervous system of the migratory locust (author's transl)]. / Etude en histofluorescence de cellules aminergiques dans le systeme nerveux central du criquet migrateur.

We have investigated the aminergic neurosecretory cells in the brain and the ganglia of the ventral nerve cord of the adult female locust, by means of the Falck and Hillarp method, with or without a block of the degradation of amines by nialamide. In the brain, we have confirmed the presence of catecholamines and probably indolamines-containing cells and defined their positions in the protocerebrum and the lateral zones of the deutocerebrum and the tritocerebrum. In the ventral cord, we have found groups of catecholaminergic cell bodies in suboesophageal, thoracic and abdominal ganglia, and probably indolaminergic cell bodies in thoracic and some abdominal ganglia. Aminergic fibres are present in all the ventral cord. They are especially numerous in suboesophageal and thoracic ganglia. In these ganglia, some fibres enter the roots of some somatic nerves.

Heart rate variations in five-month-old children during interactions in a controlled environment.

UNLABELLED: This paper reports the first data of a study on heart rate variations of 13 5-mo-old infants seated in special chairs. Their electrocardiograms and behaviour were continuously recorded during sessions that were set up with their mother and a mother-child dyad that they met for the first time when the first session was organized. The protocol comprised two interaction phases between the infants and their mothers and two with one another. The same pairs of mother-child dyads were studied a second time 1 wk later. During the first session, the infants' heart rate variability increased significantly from the mother-infant interaction phases to the infant-infant interaction phases. During the second session, the variability was higher during the mother-infant phases than in the corresponding phases of the first session. This could be linked to changes in the mothers' behaviour and the infants' idea and excitement of meeting the child from the first session again. However, the variability was significantly lower during the infant-infant phases than during the mother-infant phases and the corresponding infant-infant phases of the first session. This corresponds to the development of affiliative behaviours in the infants. CONCLUSION: When two 5-mo-old infants were seated by their mothers in special chairs, significant differences were observed in their heart rate variability when they became familiar with each other, whether they were interacting with their mothers or with one another.

Blood lactate levels of decathletes during competition.

There are many detailed physiological profiles of athletes who participate in a wide variety of sporting activities but few data have been obtained on decathletes. This study defines some physiological characteristics of these athletes and measures capillary lactate concentrations [La(b)] during a laboratory test of progressive maximal exhaustion and the different events during competition. The treadmill test is similar to the 100 m, 400 m and 1500 m in terms of [La(b)] accumulation but only similar to the 1500 m in terms of velocity. The 400 m is the most demanding event with the greatest blood lactate accumulation (mean(s.d.) 16.38(2.36) mmol l-1). The [La(b)] at the end of the 110 m hurdles is significantly lower than in any other racing events (mean(s.d.) 6.96(1.32) mmol l-1) compared with mean(s.d.) 12.14(2.87) and mean(s.d.) 11.44(2.16) for the 100 m and 1500 m respectively. The [La(b)] after the long jump, the high jump and the pole vault are not significantly different (mean(s.d.) 5.30(2.23), 4.64(1.39) and 5.36(1.34) mmol l-1) respectively).

[Emotional and attentive interferences and slow cerebral potentials (CNV-P 300) (author's transl)]. / Interférences émotionnelle et attentive et potentiels lents cérébraux (V.C.N.-P 300).

A study was conducted to establish possible correlations between electrophysiological indices and performance under neutral situations and those involving completing a double task of increasing complexity, by studying CNV and P 300 in young healthy men. The results demonstrated that: 1. After habituation, the CNV amplitudes were not related to performance. A significant correlation was noted only during the most complex tasks. 2. The CNV appears to depend mainly on endogenous factors, that is to say the aptitude and readiness of an individual to treat the information, rather than on the performance resulting from this treatment. 3. The amplitude of the P 300 is related to performance, as a function of detection rate and the complexity of the tasks. The functional duality of the CNV and the differences between it and the P 300 have been emphasized. The indices obtained from slow potentials appear to be of value for an evaluation of behaviour. Rather than analyzing the characteristics of the potentials in a supposedly "neutral" situation it would appear preferable to establish, from the indices, profiles of individual reactivity and adaptation to different experimental situations.