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Showing papers in "Neuropsychobiology in 1993"


Journal ArticleDOI
TL;DR: The results suggest that gender, genetics and nicotine consumption can influence the individual's stress responsiveness to psychological stress while personality traits showed no correlation with cortisol responses to TSST stimulation.
Abstract: This paper describes a protocol for induction of moderate psychological stress in a laboratory setting and evaluates its effects on physiological responses. The ‘Trier Social Stress Test’ (TSST) mainl

5,207 citations


Journal ArticleDOI
TL;DR: Impulsive unsocialized sensation seeking (ImpUSS) is a major factor discovered in factor analyses of scales used in psychobiological research and is strongly convergent with Eysenck's P dimension and conscientiousness in the 'big five'.
Abstract: Impulsive unsocialized sensation seeking (ImpUSS) is a major factor discovered in factor analyses of scales used in psychobiological research. It is strongly convergent with Eysenck's P dimension and conscientiousness in the 'big five'. The components of the dimension and the P scale, have been validated as correlates of various kinds of disinhibited behaviors, criminality, sexuality, and substance use and abuse. ImpUSS is related to a failure in passive avoidance learning, probably as a function of impulsivity and attention to reward stimuli. Psychophysiological markers for the trait include strong orienting and weak defensive reflexes and an augmenting, rather than reducing, of cortical reaction to intense stimuli. At the neurochemical level the trait is related to low levels of monoamine oxidase (MAO) and the neurotransmitters norepinephrine and serotonin, and theoretically high levels of dopaminergic activity. The trait components have high heritabilities for a personality trait.

167 citations


Journal ArticleDOI
TL;DR: Characteristics of the responders and nonresponders to prophylactic treatment with carbamazepine (CBZ) or lithium (Li) were investigated in a retrospective study of 215 bipolar disorder patients who had received more than 2 years of CBZ or Li treatment in Japan.
Abstract: Characteristics of the responders and nonresponders to prophylactic treatment with carbamazepine (CBZ) or lithium (Li) were investigated in a retrospective study of 215 bipolar disorder patients who had received more than 2 years of CBZ or Li treatment in Japan. Patients of mania-dominant type, with isolated occurrence of manic and depressive episodes, with onset of the illness below 30 years of age, and with atypical symptomatology, tended to respond favorably to CBZ. Rapid cyclers and patients with a past history of rapid cycling and with a continuous recurrence of episodes responded unfavorably to CBZ. Patients of mania-dominant type also showed a favorable response to Li, while patients with a continuous-type course, with rapid cycling, and a past history of rapid cycling, as with CBZ, tended to respond unfavorably to Li.

115 citations


Journal ArticleDOI
TL;DR: The relation between stress and health depends on the stress-dampening mechanisms, on how the alarm is turned off, why it sometimes seems to be left on, and what the consequences really are of leaving the alarm on.
Abstract: The stress response should be regarded as an alarm system, occurring whenever there is something missing. Lack of information (uncertainty), and the absence or loss of control produce alarm, presence of information and control (coping), or cognitive defence mechanisms (distorted stimulus expectancies) reduce the alarm. Both immune and endocrine parameters of stress are dampened by defence and coping. Biologically, these two mechanisms have different time axes. While coping is related to the fast catecholamine response, defence is related to the slower pituitary-adrenal response. The role of cortisol seems to be to suppress and dampen the acute stress response in the later phase, once it has been elicited. The relation between stress and health depends on the stress-dampening mechanisms, on how the alarm is turned off, why it sometimes seems to be left on, and what the consequences really are of leaving the alarm on.

102 citations


Journal ArticleDOI
TL;DR: It is suggested that the data of the investigation of cholinergic modulation of human information processing are consistent with the view of attention and memory as processes which operate through a common, limited capacity executive mechanism, rather than separable serial processes described in the traditional modular models of memory.
Abstract: In this paper, we describe our approach to the investigation of cholinergic modulation of human information processing. In a continuing series of studies from our laboratories, we have systematically

94 citations


Journal ArticleDOI
TL;DR: The results showed that caffeinated coffee had a beneficial effect on alertness and improved performance on a variety of tasks in both day and night sessions, and the effects were often very large.
Abstract: An experiment was carried out to examine the effects of coffee on performance and alertness in the day and at night. The results showed that caffeinated coffee had a beneficial effect on alertness and improved performance on a variety of tasks in both day and night sessions. The effects were often very large. For example, at night, consumption of caffeinated coffee produced comparable alertness ratings to the day-time ratings given when juice was drunk. In contrast to the effects of caffeinated coffee, the difference between the decaffeinated coffee and juice were small and variable. Overall, these results clearly demonstrate the beneficial effects of consuming caffeinated coffee, and show that this effect is comparable in the day and night.

92 citations


Journal ArticleDOI
TL;DR: The present paper describes the effects of dyadic social interaction in male rats with or without direct aggressive interactions on some indices of humoral and cellular immunity and suggests multiple and differential effects of social stress on immune system functioning in the rat.
Abstract: Social interactions as a consequence of the social position represent stressful conditions for the individual. Manipulation of social conditions or forming long-term social hierarchies by colony aggregation allow to investigate the regulation of immune defense mechanisms under seminatural circumstances. The present paper describes the effects of dyadic social interaction in male rats with or without direct aggressive interactions on some indices of humoral and cellular immunity. In addition, for comparative and reference purposes, in one experiment the conventional stressor of inescapable footshock was used as well. Primary humoral immune response to sheep red blood cell antigen is suppressed by repeated experience of both defeat and inescapable footshock. At individual level the social stressor is as effective as the conventional stressor of inescapable footshock, less individual rats show suppression following the social than after the conventional stress. The social stressors, i.e. being exposed to a resident or intruder of the territory, facilitate lymphocyte proliferation in the spleen by the mitogen ConA and PHA independently of the presence or absence of direct aggressive interaction. Finally, the different social stressors have some impact on the lymphocyte subpopulation in the spleen. Social stimulation without aggressive interactions increases the relative number of T-helper cells, whereas defeat leads to an increase in the T-suppressor/cytotoxic subpopulation. The data suggest multiple and differential effects of social stress on immune system functioning in the rat. Individual characteristics of the coping with stress, the social environment, and the immune indices under investigation determine the magnitude and direction of the changes in immune functioning.

80 citations


Journal ArticleDOI
TL;DR: The results indicate low P300 amplitudes to be associated with pervasive cognitive impairment and scalp locations of the maxima and minima of the P300 potentials had the tendency to be dislocated to the right in schizophrenics compared with controls.
Abstract: The parameters of auditory P300 were studied with reference-independent methods in a group of 18 remitted and residual schizophrenics, and in 18 age-and sex-matched controls. In the schizophrenic grou

77 citations


Journal ArticleDOI
TL;DR: Twelve healthy volunteers were tested in a double-blind crossover study to assess the effects of oxazepam and an extract of kava roots (Piper methysticum) on behavior and event-related potentials (ERPs) in a recognition memory task.
Abstract: Twelve healthy volunteers were tested in a double-blind crossover study to assess the effects of oxazepam and an extract of kava roots (Piper methysticum) on behavior and event-rela

72 citations


Journal ArticleDOI
TL;DR: The nervous system can generate outflow capable of signaling cells of the immune system via two routes: hormonal influences via hypothalamopituitary-target organ activation and neurotransmitter influences via direct innervation of the parenchyma of both primary and secondary lymphoid organs.
Abstract: The nervous system can generate outflow capable of signaling cells of the immune system via two routes: (1) hormonal influences via hypothalamopituitary-target organ activation, and (2) neurotransmitter influences via direct innervation of the parenchyma of both primary and secondary lymphoid organs. Both noradrenergic and neuropeptidergic nerve fibers are found directly adjacent to cells of the immune system in bone marrow, thymus, spleen, lymph nodes, and other sites. These neurotransmitters can modulate immune responsiveness at several levels, including individual cellular functions, collective cellular interactions and immune responses, and overall host immunological response to a challenge by bacteria, viruses, tumor cells, or other sources. The ability of neural signals to modulate immune responsiveness is influenced by such factors as co-localization with other neurotransmitters, synergistic or dual signaling by neurotransmitters and cytokines, hormonal influences on ligand availability or receptor responsiveness, extent of catabolism and inactivation of the neural signal, and unique chemical and morphological aspects of the specific compartmentation of the lymphoid organ in which signaling is taking place. Thus, neural-immune signaling is a complex and dynamic process, with bidirectional interactions in a complex microenvironment.

70 citations


Journal ArticleDOI
TL;DR: The results support the idea that HRV is a sensitive index for mental workload when tasks are highly demanding and subjects are motivated to exert additional effort whenever the task becomes more demanding.
Abstract: The aim of the present experiment is to evaluate heart rate variability (HRV) and cortisol as indices of mental workload in a complex environment. Heart rate was continuously recorded during flight scenarios that differed in difficulty. The HRV nicely reflected the changes in difficulty. The results support the idea that HRV is a sensitive index for mental workload when tasks are highly demanding and subjects are motivated to exert additional effort whenever the task becomes more demanding. Cortisol was only slightly increased on the experimental day compared to the training day. On the experimental day, post-task levels did not differ from pre-task levels. The level of cortisol in saliva was, however, related to overall task performance. Subjects who had a high level of cortisol had a low level of performance.

Journal ArticleDOI
TL;DR: All three androgens but not E2 are of significance to the !Kung San men's cognitive performance and DHT and the ratio DHT/Tser are positively related to verbal fluency and negatively to the degree of lateralization of tactual-spatial performance.
Abstract: The relation of circulating sex hormones and cognitive abilities was investigated in 114 healthy !Kung San men (‘bushmen’) of Namibia/Southern Africa who lived mainly as traditional hunter-gatherers.

Journal ArticleDOI
TL;DR: Increased free intracellular calcium ion concentration ([Ca2+]i) has been found in lymphocytes and blood platelets of patients with bipolar affective disorders when they are acutely ill, but not after recovery.
Abstract: Increased free intracellular calcium ion concentration ([Ca2+]i) has been found in lymphocytes and blood platelets of patients with bipolar affective disorders when they are acutely ill, but not after recovery Because lithium alters intracellular calcium ion dynamics and lowers platelet [Ca2+]i in affectively ill patients but not controls, drugs whose primary action is to modulate [Ca2+]i in hyperactive cells have been used as antimanic agents The best studied of these is verapamil, a calcium channel blocking agent (CCB) that appears most effective for lithium-responsive patients Because they interact with different central CCB receptors, second-generation CCBs may have a different spectrum of action CCBs are usually well tolerated and may be useful for a number of other psychiatric, neurological and medical conditions

Journal ArticleDOI
TL;DR: The results show the capability of cultured blood cells to produce cytokines upon endotoxin challenge to be at a maximum around the time of sleep onset and during the first hours of sleep, declining during the night to a minimum level in the morning hours.
Abstract: A growing body of evidence indicates that cytokines, especially interleukin-1 β, are involved in the regulation of sleep and wakefulness. The aim of the present pilot study was to investigate the rela

Journal ArticleDOI
TL;DR: It is demonstrated that highly controlled psychological stress increased psychophysiological variables, enhanced the secretion of sympathetic-adrenal hormones and also led to a significant increase of NK cells and their cytotoxic activity followed by a decrease below starting values.
Abstract: Emotional stress is often followed by increased susceptibility to infections. Natural killer (NK) cells play a major role in the immediate immune response controlling this susceptibility. In this study on 45 first-time parachutists, it is demonstrated that highly controlled psychological stress increased psychophysiological variables, enhanced the secretion of sympathetic-adrenal hormones and also led to a significant increase of NK cells and their cytotoxic activity followed by a decrease below starting values. This immunological alteration is correlated with the secretion of noradrenaline during the emotional strain. Quick mobilization of these cytotoxic effector cells is suggested as a major mechanism for the effective adaptation of the immune system to stress situations.

Journal ArticleDOI
TL;DR: The overall make-up and reactivity of the brain, as well as the endocrinological and immunological systems differ completely between the two types of individuals.
Abstract: An overview of the most important features of the two distinct types of individuals which normally co-occur in an unselected population of Wistar rats is given It reveals that the overall make-up and reactivity of the brain, as well as the endocrinological and immunological systems differ completely between the two types of individuals Each of these types of individuals has its own individual-specific hardware and software to cope with challenges from the internal or external environment, requires its own optimal niche, and is vulnerable for its own set of stressors

Journal ArticleDOI
TL;DR: It is suggested that manic-depressive disorder is associated with an increased sensitivity of the inositol phospholipid second-messenger generating system, which is counteracted by lithium treatment.
Abstract: The agonist-stimulated increase of intracellular free-Ca2+ concentration, an indicator of the sensitivity of the inositol phospholipid second-messenger generating system, was measured in neutrophils from patients with manic-depressive disorder, and controls. Dose-response curves of the calcium response were determined by measuring the fluorescence of neutrophils loaded with fura-2 and stimulated with various concentrations of the chemotactic tripeptide formylmethionylleucylphenylalanine. EC50 values were obtained for 14 medication-free patients (5 acutely depressive, and 9 symptom free remitted patients with a history of manic-depression or recurrent major depression), 9 lithium-treated, euthymic manic-depressive patients and 10 drug-free healthy controls. The EC50 values of the untreated patients were significantly lower than in the controls. Lithium-treated patients had EC50 values significantly higher than controls. These results suggest that manic-depressive disorder is associated with an increased sensitivity of the inositol phospholipid second-messenger generating system, which is counteracted by lithium treatment.

Journal ArticleDOI
TL;DR: It is suggested that valproate can be safely administered via a loading dose of 20 mg/kg/day to patients with acute mania, including those on other psychotropics, and that it may produce a rapid response with minimal side effects.
Abstract: Evidence from earlier studies indicates that the antimanic action of valproate becomes most apparent within 1-4 days of achieving serum concentrations 50 micrograms/ml, that valproate can be orally loaded with achievement of therapeutic serum concentrations within the first several days of treatment, there is a rapid onset of response, and minimal side effects. To provide further data on the safety and efficacy of valproate oral loading in the treatment of acute mania, we evaluated 13 consecutive patients with acute manic syndromes who received valproate initiated at a dosage of 20 mg/kg/day. In most cases, valproate was added to other psychotropics. All 13 patients received at least 5 full days of valproate maintained at or above 20 mg/kg/day, and valproate serum concentrations were 50 micrograms/ml (mean +/- SD = 88 + 25) by the second or third day of treatment. Ten (77%) patients displayed a moderate or marked response. Side effects were infrequent and minor. Consistent with our earlier study, these findings suggest that valproate can be safely administered via a loading dose of 20 mg/kg/day to patients with acute mania, including those on other psychotropics, and that it may produce a rapid response with minimal side effects.

Journal ArticleDOI
TL;DR: Immunological and neuroendocrine parameters were examined in 11 women with anorexia nervosa, 6 restricted and 5 bulimic-anorectics, and in 11 age- and sex-matched psychophysically healthy controls, and did not reveal significant differences between patients and controls.
Abstract: Immunological and neuroendocrine parameters were examined in 11 women with anorexia nervosa, 6 restricted and 5 bulimic-anorectics, 17-43 years old with 2-15 years duration of the disease, and in 11 a

Journal ArticleDOI
TL;DR: Experimental results indicate that calcium and calcium-dependent currents participate in the generation of epileptic field potentials, and neuronal PDS/EFP were depressed by organic calcium channel blockers, justifying the hope that calcium channel blocker might be useful in the treatment of human epilepsies.
Abstract: With epileptic activity, neurons show paroxysmal depolarization shifts (PDSs) corresponding to epileptic field potentials (EFPs) generated by the neuronal population. Experimental results indicate that calcium and calcium-dependent currents participate in the generation of these events. Consequently neuronal PDS/EFP were depressed by organic calcium channel blockers. This justifies the hope that calcium channel blockers might be useful in the treatment of human epilepsies.

Journal ArticleDOI
TL;DR: The segment structure of 19-channel EEG recordings from 10 patients with dementia of the Alzheimer type and 10 sex-matched geriatric controls was calculated and it was found that segments of EEG activity were significantly fewer and the segments lasted longer in patients compared to controls.
Abstract: Studies on EEG data in dementia of the Alzheimer type have mainly investigated parameters in the frequency domain. However, the EEG also reflects the momentary functional state of the brain. The EEG can be partitioned into segments of spatially stationary map landscapes as characterized by the locations of potential maxima and minima, to study the time domain of the EEG. We calculated the segment structure of 19-channel EEG recordings (1-30 Hz) from 10 patients with dementia of the Alzheimer type and 10 sex-matched geriatric controls. The EEG maps corresponding to global field power peaks were used for analysis. The locations of the potential maximum and minimum of the maps were determined over the course of 20 s and used for segmentation. The segments of EEG activity were significantly fewer (p < 0.05) and the segments lasted longer (p < 0.05) in patients compared to controls. This effect could be observed over the whole period of recording and thus was not caused by only a few long segments. The data may be linked to morphological and biochemical findings of neuronal loss and loss of synapses in dementia of the Alzheimer type.

Journal ArticleDOI
TL;DR: The present findings suggest that single medium doses of piracetam selectively activate differently located or oriented neurons during cognitive steps of information processing in healthy young men.
Abstract: We examined whether a single administration of piracetam produces dose-dependent effects on brain functions in healthy young men. In 6 subjects, 42-channel event-related EEG potential maps (ERP) were recorded during a task requiring subjects to watch single digits presented in a pseudorandom order on a screen and to press a button after all triplets of three consecutive odd or even digits. The ERP maps to the three digits of the correctly detected triplets were analyzed in terms of their mapped ERP field configuration (landscape). Different landscapes of the maps indicate different configuration of the activated neural population and therefore reflect different functional microstates of the brain. In order to identify these microstates, adaptive segmentation of the map series based on their landscapes was done. Nineteen time segments were found. These segments were tested for direct effects on brain function of three single doses of piracetam (2.9, 4.8 or 9.6 g) and a placebo given double-blind in balanced order. Piracetam mainly affected the map landscape of the time segments following the triplet's last digit. U-shaped dose-dependent effects were found; they were strongest after 4.8 g piracetam. Since these particular ERP segments are recognized to be strongly correlated to cognitive functions, the present findings suggest that single medium doses of piracetam selectively activate differently located or oriented neurons during cognitive steps of information processing.

Journal ArticleDOI
TL;DR: The findings confirm that CBZ has calcium-antagonistic properties and cause a marked reduction in the calcium currents, which in some cells was reversible.
Abstract: The effects of carbamazepine (CBZ) on action potentials and calcium currents in cultured rat sensory spinal ganglion cells were investigated. CBZ was found to reversibly suppress the calcium-dependent components of action potentials and to reduce the amplitude of the after-hyperpolarizations, while the rising phase and the peak amplitude were hardly changed. Furthermore, CBZ caused a marked reduction in the calcium currents, which in some cells was reversible. The present findings confirm that CBZ has calcium-antagonistic properties.

Journal ArticleDOI
TL;DR: The effects of CBZ on epileptic discharges in CA3 neurons of hippocampal slices were compared with those of the organic calcium antagonist verapamil and found to be almost the same.
Abstract: Carbamazepine (CBZ) is known to have beneficial effects in the treatment of epilepsies and in the prophylaxis of affective disorders. Since increased transmembrane calcium fluxes and intracellular calcium concentrations play a key role in the generation of epilepsies and possibly also in the development of these psychiatric disorders the effects of CBZ on epileptic discharges (elicited by caffeine, penicillin and low Mg2+) in CA3 neurons of hippocampal slices were compared with those of the organic calcium antagonist verapamil and found to be almost the same.

Journal ArticleDOI
TL;DR: The third edition of the DSM provided a standardized, operationalized classification system of mood disorders as discussed by the authors, and the question is raised whether this system is a good starting point for bi-lingual classification.
Abstract: The third edition of the DSM provided a standardized, operationalized classification system of mood disorders. In this paper, the question is raised whether this system is a good starting point for bi

Journal ArticleDOI
TL;DR: Investigation of premorbid, mainly personality-related background factors for first incidences of depressive disorder, diagnosed according to the Lundby criteria for 'Depression proper' and 'depression plus other psychiatric symptoms'.
Abstract: The search for specific predepressive personality factors has a long tradition in psychiatry. Studies in which assessments were made prospectively, before the onset of a first-ever episode of the illn

Journal ArticleDOI
TL;DR: Findings provide conclusive arguments for the neuroprotective effect of magnesium ions in neurologic disorders and epileptiform activity in chronically implanted rats.
Abstract: The influence of magnesium, one of the most important cations in the vertebrate body, on the sleep-wakefulness cycle and ECoG patterns in chronically implanted rats recorded during the light period over a 6-hour period was investigated Two groups of rats were studied Group 1 (6 rats): after a control period of 2 weeks, the rats were maintained for 9 weeks on a Mg(2+)-deficient diet Group 2 (5 rats): after a control period of 2 weeks, the rats were maintained for 7 weeks on a Mg(2+)-deficient diet followed by 4 weeks on a normal diet (recovery period: weeks 8-11) Mg(2+)-deficient diet for 9 weeks induced sleep and ECoG time-dependent alterations After 6-7 weeks on a Mg(2+)-deficient diet (n = 11) sleep analysis showed a significant increase of wakefulness (+50%) at the expense of slow wave sleep (-24%) but paradoxical sleep was not significantly modified After 9 weeks of a Mg2+ deficient diet, sleep was disorganized: light sleep and polyspikes occurred indicating an increase in neuronal excitability When Mg2+ was reintroduced in food and water, sleep organization and ECoG recordings were restored to their original patterns Our findings which are in line with previous clinical and pharmacological observations provide conclusive arguments for the neuroprotective effect of magnesium ions in neurologic disorders and epileptiform activity Mg2+ deficiency induces ECoG alterations in the rat which bear some similarities with those seen in neurogenic spasmophilic syndromes in man

Journal ArticleDOI
TL;DR: Using n-profiles, it appeared also possible to discriminate between antidepressant, neuroleptic, anxiolytic and psychostimulant drugs based on visual judgement.
Abstract: The effects of a number of psycho-active drugs on electrocorticographic activity (ECoG) of the rat have been studied. Frontoparietal ECoG was recorded during 6-min periods immediately before drug/vehi

Journal ArticleDOI
TL;DR: Data from the single-case longitudinal study emphasize that carbamazepine is effective in treating rapid-cycling affective psychosis, and neuroendocrine and sleep EEG data from the study in healthy subjects indicate a different profile of action for carbamazepsine compared to most other antidepressants or antimanic drugs.
Abstract: Carbamazepine treatment of a patient with 48-hour rapid cycling led to a dampening of mood cycling, and prolonged rapid eye movement (REM) sleep latency No effect on central α-receptors as measured b

Journal ArticleDOI
TL;DR: It is suggested that several antiepileptic agents--valproate, carbamazepine, and clonazepam--may have therapeutic effects in the treatment of patients with panic disorder.
Abstract: Evidence from preclinical studies, preliminary clinical reports, pharmacologic challenge studies and a small number of controlled trials suggests that several antiepileptic agents--valproate, carbamazepine, and clonazepam--may have therapeutic effects in the treatment of patients with panic disorder. We review the theoretical basis and available clinical data supporting the use of these agents in panic disorder.