Showing papers in "Neuropsychobiology in 1987"
TL;DR: Within the normal physiological range of androgen levels, testosterone levels--especially Tser and to a lesser extent DHT and Tsal--showed a significantly positive correlation with measures of spatial ability and field dependence-independence and a significantly negative correlation with Measures of verbal production.
Abstract: Blood and saliva samples were obtained from 117 healthy young men, following which radioimmunoassays were used to determine the serum concentrations of testosterone (Tser), 5α-dihydrotestosterone (DHT), and the level of free testosterone (Tsal) in the saliva. The cognitive functioning was determined by five spatial and six verbal ipsative test scores, reflecting intra-individual variance in the performance of these tasks, independent of the person’s general level of achievement. Within the normal physiological range androgen levels – especially Tser and to a lesser extent DHT and Tsal – showed a significantly positive correlation with measures of spatial ability and field dependence-independence and a significantly negative correlation with measures of verbal production.
254 citations
TL;DR: In this paper, the authors present a tutorial on spectral analysis of experimental EEG, which revisits the fundamentals of the technique, emphasizes the practical estimation of auto- and cross-spectra, discusses the assumptions underlying the spectral analysis, and concludes with a brief discussion concerning the postprocessing of spectral data.
Abstract: This tutorial was presented during the 1986 training course of the International Pharmaco-EEG Group (IPEG) in Santa Margherita Ligure, Italy. During recent years spectral analysis has been increasingly used in experimental EEG. However, to avoid misinterpretations of results, its limitations must still be carefully considered. The tutorial starts with revisiting the fundamentals of the technique, emphasizes the practical estimation of auto- and cross-spectra, discusses the assumptions underlying the spectral analysis of stochastic processes, and ends with a brief discussion concerning the postprocessing of spectral data
126 citations
TL;DR: Drug loading and metabolism can be thoroughly reduced by the application of caroverine--another important point in treatment of alcoholism, and this novel indication of a group-B Ca2+ channel blocker presents an interesting feature, which seems to warrant further investigation.
Abstract: We present a randomized double-blind study on the efficacy of caroverine in the treatment of alcohol withdrawal symptoms. The group B Ca2+ channel blocking agent caroverine was tested again
75 citations
TL;DR: Associations between platelet monoamine oxidase (MAO) activity and scale scores from the Eysenck Personality Questionnaire, the Impulsiveness-Venturesomeness-Empathy inventory and the Karolinska Scale were found in this article.
Abstract: Associations between platelet monoamine oxidase (MAO) activity and scale scores from the Eysenck Personality Questionnaire, the Impulsiveness-Venturesomeness-Empathy inventory and the Karolinska Scale
73 citations
TL;DR: A new vigilance classification rule is proposed that is based on an objective mathematical rationale for the combination of different vigilance-indicative EEG activities and patterns but which can be applied to power-spectral estimators in an automatic EEG analysis procedure.
Abstract: For the classification of sleep stages, international standards based on visual EEG analysis have been established and are in common use, although we are well aware of their limitations. Several authors have suggested different procedures for classifying the stages of vigilance during the waking stages. No universally accepted paradigm, however, has yet been developed. The proposed vigilance classification procedures are based either on visual or automatic analysis procedures. Even though the EEG activity and patterns that reflect vigilance changes have been identified and described as indicators of the state of alertness, opinion is divided on how these should be combined in a vigilance classification rule. Automatic methods, on the other hand, have up to now used only part of the information available, the relationship of which to vigilance indicators has only been partially explored. The COMSTAT (Dept. of Computation and Statistics, AFB-Arzneimittelforschung, Berlin, FRG) rule combines visual and automatic analysis procedures. Different vigilance-dependent EEG patterns, such as the proportion of occipital background rhythm under resting conditions and its replacement by either faster or slower waves, the frequency range of the occipital rhythm and the anteriorization phenomena, have been used as information for a latent class analysis (LCA5) with 5 classes (stages of vigilance). There is a high correlation between the results of the LCA5 with visual classification rules made by experts. Using a robust discriminant analysis function which takes into account prior probabilities of the classes, and with a linear cost function for misclassification, an automatic rule with power spectrum variables was fitted to the results of the LCA5. Reclassification and split-half classification showed a high overlap between LCA5 and automatic classification. The result of this procedure is a new vigilance classification rule that is based on an objective mathematical rationale for the combination of different vigilance-indicative EEG activities and patterns but which can be applied to power-spectral estimators in an automatic EEG analysis procedure.
60 citations
TL;DR: Scopolamine induced a dose-related increase of relative power in low- and high-frequency components and a decrease in the range 8.0-13.5 Hz and in total signal power, which appears to be a suitable dose for pharmaco-EEG studies.
Abstract: There has been clinical and experimental evidence that cholinergic compounds and precursors of choline are potentially useful in the treatment of dementia. Anticholinergic compounds have also been proposed as a possible acute model for pharmaco-EEG studies focussed on CNS aging. Single doses of scopolamine (0.25–0.75 mg i.m.) and a matching placebo were administered to 8 young healthy volunteers. Quantitative EEG recordings and neuropsychological testing were performed in baseline conditions prior to and 30, 90 and 120 min after drug administration. Scopolamine induced a dose-related increase of relative power in low- and high-frequency components and a decrease in the range 8.0–13.5 Hz and in total signal power. These modifications were found to be limited to the posterior scalp electrode derivations and were observed from the 90-min control onwards. Concomitantly, there was a significant impairment in the subjects’ response to neuropsychological testing after the administration of 0.50 and 0.75 mg of scopolamine. At a dose of 0.75 mg, volunteers complained about subjective symptoms which were definitely unpleasant. The effects of this dose on the EEG and the neuropsychological status did not differ significantly from those observed after a dose of 0.50 mg. As regards dose and tolerance, 0.50 mg of scopolamine administered intramuscularly appears to be a suitable dose for pharmaco-EEG studies.
59 citations
TL;DR: In two studies experimentally induced colds slowed the speed of response in a serial reaction task, which shows that performance on such a task may be used to predict subsequent illness.
Abstract: In two studies experimentally induced colds slowed the speed of response in a serial reaction task. Responding was also slower during the incubation period of the illness, which shows that performance on such a task may be used to predict subsequent illness. Volunteers who had no significant clinical illness, but who had a significant rise in IgG following virus challenge, also showed changes in performance. In contrast to the serial reaction task, neither colds nor subclinical infections impaired performance on a detection task.
53 citations
TL;DR: The amount of cortisol is again raised after a period of sleep deprivation and simultaneously the amplitude becomes larger, and the heart rate in the entire circadian course is significantly increased by antidepressants.
Abstract: Free cortisol in urine, temperature and heart rate were examined in 81 endogenous depressives and 15 healthy controls in five successive 24-hour rhythms. The nocturnal mean value, amplitude, phase pos
53 citations
TL;DR: Insulin activity in plasma and the concentrations of tryptophan and serotonin were measured during the glucose tolerance test (GTT) in habitually violent and impulsive male offenders and in psychiatric personnel as controls to assess enhanced insulin secretion in intermittent explosive disorder.
Abstract: Insulin activity in plasma and the concentrations of tryptophan and serotonin were measured during the glucose tolerance test (GTT) in habitually violent and impulsive male offenders and in psychiatric personnel as controls. Insulin was enhanced in the intermittent explosive disorder; at the same time the concentration of plasma tryptophan and the ratio of tryptophan to large neutral amino acids were on a high level and tryptophan even increased in many cases during GTT. Serotonin values did not differ. Many offenders with enhanced insulin secretion displayed abnormal neuroglycopenic symptoms during GTT.
51 citations
TL;DR: The EEG was quantified by spectrum analysis, the topographic structure displayed by brain mapping techniques, and the results compared with earlier studies which used the same design and drugs, and there was an increase of both slow and fast beta.
Abstract: In a double-blind fourfold crossover design, 11 subjects were randomly assigned to placebo, 10 mg diazepam, 75 mg amitriptyline, and 75 mg chlorpromazine. During a simple vigilance task, 12 midline and left hemisphere leads were recorded before and 3 h after drug administration. The EEG was quantified by spectrum analysis, the topographic structure displayed by brain mapping techniques, and the results compared with earlier studies which used the same design and drugs. Diazepam showed the expected increase in beta; however, fast beta was increased as much as slow beta. Amitriptyline showed an increase of slow wave power and a reduction of alpha. In contrast to earlier studies, a decrease of fast beta was found. In addition, the spatial pattern of alpha changed from an occipital to a parietal maximum. Chlorpromazine showed an increase in the theta band. In occipital regions, there was a small decrease of fast beta; however, centrally there was an increase of both slow and fast beta. These results were confirmed by a multivariate analysis of variance.
46 citations
TL;DR: In a double-blind, placebo-controlled trial of treatment with the neuroleptic pimozide, negative symptoms improved in schizophrenic patients who showed an antipsychotic response and there was a significant positive correlation between changes in positive and negative symptoms.
Abstract: In a double-blind, placebo-controlled trial of treatment with the neuroleptic pimozide, negative symptoms improved in schizophrenic patients who showed an antipsychotic response. Furthermore, there was a significant positive correlation between changes in positive and negative symptoms for the group as a whole, including both pimozide responders and nonresponders. In our patient sample, neuroleptic treatment did not exert a differential effect on the positive and negative symptoms of schizophrenia. It is conceivable that negative symptoms are state dependent and may become neuroleptic nonresponsive over time just as positive symptoms do in some chronic patients.
TL;DR: The results are in accordance with the drug's proposed action of enhancing the dopaminergic transmission, which probably implies an indirect mechanism of action as biochemically no direct interaction with any of the dopamine receptors has been described for memantine so far.
Abstract: Chronic implantation of four bipolar concentric electrodes into frontal cortex, hippocampus, striatum and reticular formation allows repetitive recordings of field potentials from freely moving rats.
TL;DR: Comparisons suggest that the neurological and neurochemical changes observed may play common roles in similar behavioral deficits observed in aged animals and humans.
Abstract: In this article the effects of neurotransmitter systems or specific drugs on cognitive functions of aged animals and humans are reviewed. While there have been used many different pharmacologic and behavioral approaches to treat and test cognitive deficits in aged animals and geriatric or demented patients, there is still the question of the validity of animal models of human disorders. Attempts are made to show that there are parallels and similarities. These similarities suggest that the neurological and neurochemical changes observed may play common roles in similar behavioral deficits observed in aged animals and humans.
TL;DR: The ability of chronic treatment with imipramine to antagonise the anxiogenic effects of 3 different compounds was investigated in the elevated plus-maze and the nature of the anxiety produced by the anxuogenic drugs and the sensitivity of tests of anxiety to anti-panic agents were discussed.
Abstract: The ability of chronic treatment with imipramine (an antidepressant with anti-panic activity) to antagonise the anxiogenic effects of 3 different compounds was investigated in the elevated plus-maze.
TL;DR: Night sleep of patients after anesthesia is disturbed not only by intensive care unit conditions, but also by direct effects of narcotics and surgery.(ABSTRACT TRUNCATED at 250 WORDS)
Abstract: Sleep rhythm can be influenced by narcotics and exogenous disturbances causing persistent insomnia, exhaustion and moodiness. In this study the influence of anesthesia on the patients’ sleep during th
TL;DR: Even though the patients gained significantly in age and body weight during the treatment, their mean blood sugar values remained the same as before treatment was started, and only 1 patient developed manifest diabetes.
Abstract: Fasting blood sugar was determined in manic-depressive patients before the start of lithium treatment and at intervals during treatment for up to 6 years. The total exposure time to lithium was 495.5 years. Even though the patients gained significantly in age and body weight during the treatment, their mean blood sugar values remained the same as before treatment was started, and only 1 patient developed manifest diabetes. There is no reason to believe that long-term lithium treatment leads to increased risk of developing diabetes mellitus.
TL;DR: It was found that a history of perinatal distress was much more common in the poor prognosis group than in the good prognosis groups, and this difference could not be accounted for by age or family history of psychiatric illness.
Abstract: The medical histories of a group of 511 patients hospitalized for schizophrenia were examined for the occurrence of perinatal distress. These patients were part of a 40-year follow-up study, so that their prognostic outcome was known at the time of this study. In this way, 200 cases of chronic schizophrenia were compared with 311 cases of psychotics with good prognosis. It was found that a history of perinatal distress was much more common in the poor prognosis group than in the good prognosis group. This difference could not be accounted for by age or family history of psychiatric illness.
TL;DR: A tendency to lowered Vmax values in the follicular phase in women with PMS during spring may indicate that women withPMS are more vulnerable to developing depressive episodes during this period than symptom-free women.
Abstract: The platelet serotonin uptake kinetics was studied in 19 women with premenstrual tension syndrome (PMS) and 19 age-matched symptom-free controls during the pre- and postmenstrual phases. Both groups e
TL;DR: A significant correlation was observed between some indices of the nonspatial task and the scores on two subscales of the scale for the assessment of negative symptoms by Andreasen, consistent with the hypothesis of a dysfunction of dorsolateral prefrontal cortex in schizophrenia and with the postulated linkage between such dysfunction and negative schizophrenia symptomatology.
Abstract: The performance on spatial and nonspatial associative learning tasks was tested in a sample of male drug-free DSM III-diagnosed schizophrenic patients and in a closely matched normal control group. Schizophrenics showed a worse performance on both versions of the task, but especially on the nonspatial one. A significant correlation was observed between some indices of the nonspatial task and the scores on two subscales (affective flattening and anhedonia) of the scale for the assessment of negative symptoms by Andreasen. These results are consistent with the hypothesis of a dysfunction of dorsolateral prefrontal cortex in schizophrenia and with the postulated linkage between such dysfunction and negative schizophrenic symptomatology.
TL;DR: Two compounds that have anti-panic activity in man, the tricyclic antidepressant imipramine and the alpha 2-adrenoceptor agonist clonidine, were used to try to antagonise the anxiogenic effects of the 2 drugs, believed to act at different sites on the GABA-benzodiazepine receptor complex.
Abstract: The beta-carboline FG 7142 and pentylenetetrazole, believed to act at different sites on the GABA-benzodiazepine receptor complex, have anxiogenic activity in the social interaction test in the rat. Two compounds that have anti-panic activity in man, the tricyclic antidepressant imipramine and the alpha 2-adrenoceptor agonist clonidine, were used to try to antagonise the anxiogenic effects of the 2 drugs. Imipramine (5 and 15 mg/kg) was tested after 0 or 15 days pretreatment. In neither case was it able to reverse the anxiogenic effect of pentylenetetrazole (15 mg/kg). However, after chronic treatment the effects of FG 7142 were reversed. Imipramine itself had an anxiogenic action that was significant after acute treatment, and its effects were not additive with those of FG 7142 or pentylenetetrazole, suggestive of some mutual antagonism between acute imipramine and the 2 drugs. Similar mutual antagonism was obtained after acute treatment with clonidine (0.01 and 0.025 mg/kg).
TL;DR: The data obtained in rats support the 'tension reduction hypothesis' of human alcoholism and would place individuals with a high stress response at greatest risk to abuse alcohol.
Abstract: Individual male and female Sprague-Dawley rats with indwelling jugular catheters were subjected to restraint stress both without and with pretreatment with 1 g/kg ethanol (i.p., 20% w/v in water). Pla
TL;DR: The results suggest that high CO absorbing smokers possibly depend more on neuropharmacological effects of smoking than smokers with a low amount of CO absorption, and support the assumption of the distraction arousal model used as an interpretation of these effects on contingent negative variation.
Abstract: The present study relates subject-paced rapid information processing to different components of event-related brain potentials in an attempt to gain more information about changes in mental performance in relation to alveolar smoke absorption as assessed by expired air CO measurement. The task consisted in the presentation of pseudorandom sequences of single digits, and the subjects had to respond to each sequence of three odd or three even digits. The triplets evoked a typical late negativity in the event-related potential between the second and third digit as well as a P300 component following the third digit. In 21 smokers, task performance, event-related potentials and tidal air CO concentration were measured before and after smoking a cigarette. The results revealed increases in performance and P300 magnitude from pre- to postsmoking which were unaffected by the amount of CO absorption. A differential trend was seen, however, with the late negativity, which increased from pre- to postsmoking only in subjects with a large amount of CO absorption. The results support the assumption of the distraction arousal model used as an interpretation of these effects on contingent negative variation and suggest that high CO absorbing smokers possibly depend more on neuropharmacological effects of smoking than smokers with a low amount of CO absorption.
TL;DR: It was found that paroxetine and zimeldine at doses of 1-18 mg/kg dose-dependently prolonged waking and shortened slow-wave sleep and paradoxical sleep, and 5-HT uptake inhibitors increase vigilance in rats at oral doses which selectively stimulate the serotoninergic system.
Abstract: The effects of oral paroxetine and zimeldine on EEG sleep-waking phases in the rat were investigated over a wide dose range. To ascertain that at the doses used for the EEG studies paroxetine and zimeldine selectively affect the serotoninergic system, their effects on brain 5-hydroxytryptamine (5-HT), dopamine and noradrenaline were determined. It was found that paroxetine and zimeldine at doses of 1–18 mg/kg dose-dependently prolonged waking and shortened slow-wave sleep and paradoxical sleep. In the same dose range cortical 5-HT turnover was significantly reduced, whereas the other aminergic systems were not influenced. These results suggest that 5-HT uptake inhibitors increase vigilance in rats at oral doses which selectively stimulate the serotoninergic system.
TL;DR: Lymphoblast beta receptor binding was analyzed by Scatchard plot, using cell lines established from 17 unrelated bipolar subjects and 14 normals, finding no significant differences in affinity or density of beta receptors.
Abstract: Beta-adrenergic receptor function has been the subject of much research in manic-depressive illness. Lymphoblast beta receptor binding was analyzed by Scatchard plot, using cell lines established from 17 unrelated bipolar subjects and 14 normals. No significant differences in affinity or density of beta receptors were found, in contrast to a previous report. Both the affinity and density of receptors appeared to be a stable characteristic of a cell line, as determined by repeated assay of the same cell lines.
TL;DR: The anxiolytic profile is compared with the formerly defined antidepressant and neuroleptic profiles and can be clearly distinguished from the latter two.
Abstract: Electroencephalograms were recorded from the parietal and frontal cortex of freely moving rats held in constant vigilance by placing them in a slowly turning drum. The effects of 5 clinically effectiv
TL;DR: There was a syndrome-specific interaction effect with task difficulty: Schizophrenics with positive symptoms performed poorly, especially in the most difficult task condition, and there was no significant relationship between daily neuroleptic dose and tracking performance.
Abstract: 30 schizophrenic outpatients (RDC) under neuroleptic maintenance treatment completed a visuomotor tracking task with four degrees of difficulty. The mean efficiency of performance was measured in bit per second from the difference between the target signal and the tracking signal. Clinical assessment was accomplished with the BPRS, CGI, and GAS. Besides generally poorer tracking performance in schizophrenics compared with healthy volunteers the main finding was a relationship between tracking performance and psychopathological subtyping. Negative symptoms were related to a generally lowered task performance, irrespective of task difficulty. However, this effect disappeared by controlling for illness duration. On the other hand, there was a syndrome-specific interaction effect with task difficulty: Schizophrenics with positive symptoms performed poorly, especially in the most difficult task condition. Generally, there was no significant relationship between daily neuroleptic dose and tracking performance. Results are discussed with respect to a differential deficit in attention in schizophrenic subgroups.
TL;DR: The measurement of saliva cortisol at 11 p.m. could be used alone as a reliable and practical index of hypothalamic-pituitary-adrenal axis activity in depression, especially in outpatients.
Abstract: Saliva cortisol was measured at 11 p.m. in a sample of 74 psychiatric inpatients composed of 24 primary endogenous depressives, 40 secondary depressives and 20 nondepressives (DSM III and Saint-Louis
TL;DR: The present study shows that the reversal of depressive-like behavior in rats was markedly attenuated in hypothyroid rats, which supports the notion of intricate thyroid/CNS interactions in the mechanisms of action of antidepressant drugs.
Abstract: Several investigations have suggested that a special relationship exists between thyroid function and affective disorders and/or therapeutic response to antidepressants. The present study shows that the reversal by clomipramine, desipramine, imipramine and nialamide of depressive-like behavior in rats (escape deficits produced by previous exposure to uncontrollable stress) was markedly attenuated in hypothyroid rats (propylthiouracil, 0.05% in the drinking water). Conversely, the effect of these same antidepressants was significantly hastened in euthyroid rats given daily triiodothyronine. This supports the notion of intricate thyroid/CNS interactions in the mechanisms of action of antidepressant drugs.
TL;DR: Some methods to overcome the problem caused by the nonstationarity of the EEG include measures of variability, condensed time series and segmentation, and FFT spectral estimators and broad-band parameters derived thereof.
Abstract: In many situations, EEG recordings cannot be assumed to be second-order stationary. The definition of stationarity is reviewed and the implications of the nonstationarity of the EEG are investigated. Some methods to overcome the problem caused by the nonstationarity are discussed. They include measures of variability, condensed time series and segmentation. The discussion is restricted to FFT spectral estimators and broad-band parameters derived thereof.