摘要:

We studied 18 never-medicated schizophrenic patients and 22 normal control subjects with 18F-deoxyglucose (FDG) positron emission tomography. Patients and controls performed the continuous performance test during FDG uptake. Cortical and subcortical structures comprising two circuits selected on the basis of several theoretical models of schizophrenia were examined. The correlation of glucose metabolic rate (GMR) for each structure in each circuit with connected structures was calculated and tested for two-tailed significance. Schizophrenics showed significantly different patterns of intercorrela-tions for both circuits. The largest difference was in the correlation of GMR in the anterior thalamus with the frontal cortex, a key element in the thalamo-cortical-striatal circuit suggested to be abnormal in some models of schizophrenia. Correlations of the frontal lobe with other regions were also more positive in normal controls than schizophrenics; controls had three correlational paths from the frontal cortex (to temporal cortex, ventral anterior thalamus, and dorsal medial thalamus) with significantly more positive correlations than schizophrenics, perhaps consistent with other findings of frontal cortical dysfunction in schizophrenia. Normal controls also had both more significant positive and more significant negative correlations between the occipital cortex and other brain areas than schizophrenics. Correlations between homologous areas in the right and left hemispheres were prominent in both groups.

ISSN:0302-282X    

DOI:10.1159/000119241

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Haloperidol (HL) and reduced haloperidol (RH) plasma concentrations were measured in geriatric patients (n = 45) and schizophrenic patients (n = 8). In the elderly patients, HL doses were 1–4 mg/day while only 2 mg/day was used in the schizophrenics. At HL 2 mg/day dose in both age groups, mean plasma HL levels were approximately twice as high in the elderly patients compared to the schizophrenics (1.39 ± 0.82 vs. 0.56 ± 0.23 ng/ml, p < 0.02). RH plasma concentrations were almost 5 times greater in the elderly patients (0.54 ± 0.35 vs. 0.09 ± 0.05 ng/ml, p < 0.0001). These results suggest that HL plasma concentrations in the elderly are greater than in adult schizophrenic patients treated with similiar HL

ISSN:0302-282X    

DOI:10.1159/000119242

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The effects of the addition of short-term lithium to long-term administration of antidepressants (clomipramine or citalopram) on the levels of 5-HT and 5-HIAA and serotonergic receptors were studied in the rat cortex. The addition of short-term Li to long-term antidepressant treatment potentiated an increase in 5-HIAA, although Li alone had no effect. On the serotonergic receptors, the addition of short-term Li had no effect. It is speculated that the therapeutic action of Li when added to antidepressants in the treatment of refractory depression may partly have its basis in the further activation of the presynaptic serotonergic system.

ISSN:0302-282X    

DOI:10.1159/000119243

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Repeated amphetamine (A) or methamphetamine (M) treatment induces behavioral sensitization and drug conditioning. The present study compared behavioral sensitization and drug conditioning between treatments with M combined with scopolamine (S) and M alone with respect to a reciprocal balance between the dopaminergic and inhibitory cholinergic systems in rats. Repeated treatment with M (4.0 mg/kg i.p.) combined with S (0.5 mg/kg i.p.) (MS) produced progressive enhancement of stereotyped behavior, compared with repeated M treatment alone. Repeated MS treatment induced focussed stereotyped behavior that was elicited by every challenge injection of not only MS and M, but also partially by S. MS- but not M-sensitized rats exhibited conditioned responses to a tone (300 Hz, 100 dB) associated with drug state, suggesting that MS-induced pronounced behavioral sensitization may lead to an enhanced conditioned response to the conditioned stimulus (CS) of a tone. It is suggested that MS-induced behavioral sensitization may be mediated via a reciprocal balance between the dopaminergic and cholinergic systems in favor of a dopaminergic dominance, and that such a balance may be involved in the conditioning to the drug-associated tone CS.

ISSN:0302-282X    

DOI:10.1159/000119244

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The effect of daily forced swimming (15 min) of rats for 21 consecutive days on peripheral-type bentodiazepine receptors (PBR) was investigated. A significant reduction (–17%; p < 0.05) was observed in renal PBR in the stressed animals. A nonsignificant reduction of –18% was detected in adrenal PBR. The maximal binding capacity of [3H]PK 11195 was unaltered in the liver, heart, testis and thymus. It seems that the kidney is especially sensitive to repeated stress. The renal PBR reduction may be related to habituation to stress, and may reflect an adaptatory mechanism aimed at preventing long-term stress-induced overactivity of the reninangiotensin sys

ISSN:0302-282X    

DOI:10.1159/000119245

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

In elderly subjects there is a vigilance decrease from morning to noon which was used in a clinical pharmacological model as a state condition to verify vigilance-enhancing effects of an antidementia drug. In this model the effects of Memantine (20 mg, single-dose application) on the quantified EEG were investigated in 16 elderly (mean age: 65 ± 5 years), healthy subjects (10 females, 6 males) in a randomised, twofold cross-over design vs. placebo under double-blind conditions. EEG was recorded before medication, and 2 and 4 h after medication under reaction time (RT) and resting (RS) conditions. EEG data were subjected to spectral analysis and the topographic distribution of the amplitude values was mapped. The results show that a time-dependent decrease (from morning to noon) in vigilance (indicated by an increase in average EEG amplitudes caused by increased synchronisation in the alpha and beta range and an increase in delta) occurred under placebo which was counteracted by Memantine. The diurnal variations of the EEG and their compensation by a pharmacological agent represent an effective model for investigating the vigilance-enhancing effects of antidementia drugs

ISSN:0302-282X    

DOI:10.1159/000119246

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

In the present study we investigated the influence of pulsed high-frequency electromagnetic fields of digital mobile radio telephones on sleep in healthy humans. Besides a hypnotic effect with shortening of sleep onset latency, a REM suppressive effect with reduction of duration and percentage of REM sleep was found. Moreover, spectral analysis revealed qualitative alterations of the EEG signal during REM sleep with an increased spectral power density. Knowing the relevance of REM sleep for adequate information processing in the brain, especially concerning mnestic functions and learning processes, the results emphasize the necessity to carry out further investigations on the interaction of this type of electromagnetic fields and the human organism.

ISSN:0302-282X    

DOI:10.1159/000119247

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Quantitative electroencephalogram (QEEG) changes induced by the acute administration of moclobemide (200 mg) in patients with major depression include a transient increase in theta-activity, a slight augmentation of alpha-activity and a sustained increase in beta-activity. This QEEG profile distinguishes moclobemide from sedative antidepressants. A 42-day treatment with 400 mg/day of the drug produces a significant decrease in the late positive-complex peak latency of the event-related potentials, suggesting a positive effect on attention and cognitive functions.

ISSN:0302-282X    

DOI:10.1159/000119248

出版商:S. Karger AG    

年代:1996

数据来源: Karger