摘要:

The renal function was assessed in 51 bipolar patients on multiple-dosage lithium maintenance therapy from 1 to 22 years, after placing them on single (HS) dosage for 12–18 months. Serum lithium levels were maintained constant at a level of 0.8 mg/1. The patients were divided into three groups according to duration of previous multiple doses (b.i.d.–q.i.d.) Li therapy; less than 5 years; 5–10 years; 10–22 years. The improvement in water handling occurred only in the previously shortest multiple-dosage-treated patients and the duration of previous multiple dosage negatively influenced water handling; however, all laboratory analyses remained within normal limits. None of the patients showed clinical worsening or had an affective episode. The separate analyses showed associated gender differences in urinary volume, serum creatinine, and creatinine clearance values. Our findings confirmed the beneficial renal reaction to single-dose posology, as well the female sensitivity to Li therapy in general, and especially with concomitant antipsychotic med

ISSN:0302-282X    

DOI:10.1159/000119301

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The 4-vessel occlusion model of ischaemia in the rat was used to assess the effects of two dopaminergic agonists, lisuride and piribedil, on some behavioural and histological changes. Animals were either sham-operated, subjected to 20 min 4-vessel occlusion, or administered lisuride (0.5 mg/kg i.p.) or piribedil (10 mg/kg i.p.) 1 h before 20 min 4-vessel occlusion. Both drugs attenuated deficits in neurological testing, Morris water maze and 14-unit T-maze (p < 0.05). Extensive neuronal death was observed in the CA1, CA3 and CA4 regions of the hippocampus of 4-vessel-occluded animals. Pretreatment with both lisuride and piribedil provided protection against cell death in the hippocampal regions. These findings suggest dopamine may play a role in cerebral ischaemia and dopaminergic agonists may be beneficial in preventing isch-aemia-induced neurodegeneration.

ISSN:0302-282X    

DOI:10.1159/000119302

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:0302-282X    

DOI:10.1159/000119303

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The early research on an animal (cat) model and biological marker (visual evoked potential augmenting and reducing) of sensation seeking behavior is briefly described. Recent findings with selectively bred lines of rats show that (1) the relationship between sensation seeking behavior and augmenting vs. reducing is also present in the rat; (2) augmenting and reducing is a cortical, not a subcortical, phenomenon, and (3) augmenting/reducing and related sensation seeking behaviors are heritable traits. This paper also discusses evidence for the relative contributions of genetic and environmental factors in determining the sensation seeking trait.

ISSN:0302-282X    

DOI:10.1159/000119304

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

A behavioral trait in rats which resembles some of the features of high-sensation seekers in man has been characterized. Given that the response to novelty is the basis of the definition of sensation-seeking, individual differences in reactivity to novelty have been studied on behavioral and biological levels. Certain individuals labeled as high responders (HR) as opposed to low responders (LR) have been shown to be highly reactive when exposed to a novel environment. These groups were investigated for free-choice responses to novel environments differing in complexity and aversiveness, and to other kinds of reinforcement, i.e. food and a drug. The HR rats appeared to seek novelty, variety and emotional stimulation. Only HR individuals have been found to be predisposed to drug-taking: they develop amphetamine self-administration whereas LR individuals do not. They also exhibit a higher sensitivity to the reinforcing properties of food. On a biological level, compared to LR rats, HR animals have an enhanced level of dopaminergic activity in the nucleus accumbens both under basal conditions or following a tail-pinch stress. HR and LR rats differ in reactivity of the corticotropic axis: HR rats exposed to a novel environment have a prolonged secretion of corticosterone compared to LR rats. The association of novelty, drug and food seeking in the same individual suggests that these characteristics share common processes. Differences in dopaminergic activity between HR and LR rats are consistent with results implicating these dopaminergic neurons in response to novelty and in drug-taking behavior. Given that rats self-administer corticosterone and that HR rats are more sensitive to the reinforcing properties of corticoste-roids, it could be speculated that HR rats seek novelty for the reinforcing action of corticosterone. These characteristics may be analogous to some for the features found in human high-sensation seekers and this animal model may be useful in determinating the biological basis of this human trait.

ISSN:0302-282X    

DOI:10.1159/000119305

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The focus concerns psychobiological risk factors in the development of antisocial behavior among male and female subjects. Using longitudinal data, violent and nonviolent criminal offences were studied in relation to childhood vulnerability indicators, norm-breaking behavior in adolescence, and to personality traits and biochemical measures in adult age. Subsequently, levels of norm-breaking behavior in adolescence were studied as related to personality and biochemical measures in adult age. Data were obtained from a representative group of 82 male and 87 female subjects as (1) teacher ratings of behavior at age 13, assumed to differentially reflect vulnerability to externalizing and internalizing psychosocial disturbances; (2) self-ratings of norm-breaking behaviors at age 15; (3) Karolinska Scales of Personality scores and biochemical measures at age 26–27 years, and (4) records for criminal offences up to age 40. In both the male and female groups, criminal offences during the life span were associated with childhood externalizing and adolescent norm-breaking behavior. Furthermore, in the male group, criminal and violent offences were associated with adult psychopathy-related personality traits and a biochemical indicator of psychosocial vulnerability; platelet monoamine oxidase (MAO) activity. Among female subjects, criminal offenders displayed significantly lower MAO activity in comparison to noncriminals. High levels of norm-breaking behavior in adolescence were associated with adult high impulsiveness, low socialization, and low platelet MAO activity in both male and female subjects. The results of the analyses were used as a basis for some theoretical and methodological conclusion

ISSN:0302-282X    

DOI:10.1159/000119320

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The purpose of the present paper was to investigate the relationship of the serotonergic and dopaminergic systems to subscales of sensation seeking (SS). Two of the subscales, Disinhibition (DIS) and Experience Seeking (ES), were chosen for analysis based on their representation of the two major factors obtained in a factor analysis: DIS represents a factor of lack of impulse control and ES a factor of novelty seeking. In studies 1 and 2 responsivity to a serotonergic (5-HT) challenge by a 5-HT1a receptor agonist (ipsapirone) was investigated by drug-induced prolactin (PRL) and cortisol responses, as well as by emotional states and behavioral measures. The dopaminergic (DA) response to a DA agonist (lisuride) and antagonist (fluphenazine) was analyzed in a condition of smoking deprivation (study 3) using PRL responses, emotional states, and behavioral measures of nicotine craving as dependent variables. In the studies of the serotonergic system, high ES subjects showed a blunted cortisol response in both studies and high DIS subjects demonstrated a blunted PRL response in study 2. A frequently observed side effect of serotonergic agonists, increase in emotional arousal, was not observable with ipsapirone in high ES and high DIS subjects as compared to low scorers. Behavioral aggression, which had been experimentally induced in study 2, was increased in high ES as well as in high DIS by the 5-HT1a agonist which exerted antiaggressive effects in low scorers. These findings were found compatible with the idea of a generally low responsivity of the serotonergic system in high ES as well as in high DIS types of sensation seekers or 5-HT1a subsensitivity in high DIS and subsensitivity of other postsynaptic 5-HT receptors in high ES. There was no association between SS subscales and DA-induced decrease of PRL, but high ES subjects seemed to tolerate nicotine deprivation better than low ES subjects indicating that they were less susceptible to deprivation of nicotine-induced DA. But craving for nicotine was increased in high ES subjects by the DA agonist lisuride as opposed to the antagonist, which was taken as evidence that DA stimulation may induce approach behavior in high ES. Although only two subscales had been selected for the investigation, this approach suggests both common and different relationships between SS subscales and neurotransmitter systems.

ISSN:0302-282X    

DOI:10.1159/000119318

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Physiological signals recorded after presentation of a stimulus can be considered as the sum of an evoked sensory response and uncorrelated noise corresponding to the spontaneous neural background activity. In case of low signal-to-noise ratio, the sensory signal is estimated by averaging a large number of single trial records sampled under the same experimental conditions. The averaging technique, however, is inappropriate for displaying trial-to-trial variations that may occur during a recording session. A method based on matched filtering was developed for processing single visual evoked potentials (VEPs). To illustrate the performance of this method, a set of VEPs for grating patches of 8 different contrasts (including 0) was evaluated. The VEPs were subjected to signal detection analysis by computing for each contrast similarity indices between the single trial records and the averaged response used as a template. The signals were analysed in terms of probability density distributions, expressing the goodness of fit between template and each single waveform.

ISSN:0302-282X    

DOI:10.1159/000119319

出版商:S. Karger AG    

年代:1996

数据来源: Karger