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Tricyclic antidepressants and selective serotonin reuptake inhibitors are here shown to induce cell death in a neural cell line. The exposure to these drugs led to increased generation of reactive oxygen species and a concomitant reduction of intracellular glutathione levels. Furthermore, these antidepressants induced DNA fragmentation and increased the transcriptional and DNA-binding activity of NF-kappaB. In contrast, treatment with type A and B monoamine oxidase inhibitors did not induce changes in NF-kappaB activity and did not exert a detrimental influence on cell viability. These results indicate that some antidepressant drugs may cause both oxidative stress and changes in cellular antioxidative capacity, resulting in altered NF-kappaB activity and, ultimately, cell death.

Deficiency of CRH receptor 1 (CRHR1) severely impairs the stress response of the hypothalamic-pituitary-adrenocortical (HPA) system and reduces anxiety-related behavior in mice. Intriguingly, in mice deficient for the CRHR1 (Crhr1-/-), basal plasma levels of ACTH are normal, suggesting the presence of compensatory mechanisms for pituitary ACTH secretion. We therefore studied the impact of the hypothalamic neuropeptides arginine vasopressin (AVP) and oxytocin (OXT) on HPA system regulation in homozygous and heterozygous Crhr1 mutants under basal and different stress conditions. Basal plasma AVP concentrations were significantly elevated in Crhr1-/- mice. AVP messenger RNA expression was increased in the paraventricular nucleus of Crhr1-/- mutants together with a marked increase in AVP-like immunoreactivity in the median eminence. Administration of an AVP V1-receptor antagonist significantly decreased basal plasma ACTH levels in mutant mice. After continuous treatment with corticosterone, plasma AVP levels in homozygous Crhr1-/- mice were indistinguishable from those in wild-type littermates, thus providing evidence that glucocorticoid deficiency is the major driving force behind compensatory activation of the vasopressinergic system in Crhr1-/- mice. Neither plasma OXT levels under several different conditions nor OXT messenger RNA expression in the paraventricular nucleus were different between the genotypes. Taken together, our data reveal a selective compensatory activation of the hypothalamic vasopressinergic, but not the oxytocinergic system, to maintain basal ACTH secretion and HPA system activity in Crhr1-/- mutants.

Using intracerebral microdialysis in urethane-anaesthetized adult male Wistar rats, we monitored the effects of acute repetitive transcranial magnetic stimulation (rTMS; 20 trains of 20 Hz, 2.5 s) on the intrahypothalamic release of arginine vasopressin (AVP) and selected amino acids (glutamate, glutamine, aspartate, serine, arginine, taurine, gamma-aminobutyric acid) and the intrahippocampal release of monoamines (dopamine, noradrenaline, serotonin) and their metabolites (homovanillic acid, 3,4-dihydroxyphenylacetic acid, 5-hydroxyindoleacetic acid). The stimulation parameters were adjusted according to the results of accurate computer reconstructions of the current density distributions induced by rTMS in the rat and human brains, ensuring similar stimulation patterns in both cases. There was a continuous reduction in AVP release of up to 50% within the hypothalamic paraventricular nucleus in response to rTMS. In contrast, the release of taurine, aspartate and serine was selectively stimulated within this nucleus by rTMS. Furthermore, in the dorsal hippocampus the extracellular concentration of dopamine was elevated in response to rTMS. Taken together, these data provide the first in vivo evidence that acute rTMS of frontal brain regions has a differentiated modulatory effect on selected neurotransmitter/neuromodulator systems in distinct brain areas.

Transgenic mice with impaired glucocorticoid receptor (GR) function were tested for their ability to learn and perform a series of simultaneous visual discriminations which allowed a dissociation between accuracy of discrimination from those of motivation and behavioural disinhibition. Animals were first trained on an operant five-choice simultaneous discrimination autoshaping procedure, followed by a continuous reinforcement schedule on that task. Subsequently, the number of choices was limited to two and data were analysed according to the mathematical methods of signal detection theory (SDT). The effects of GR-antisense expression on accuracy when different rates of responding were required were studied under different fixed ratio response requirements (FR1-FR10). Autoshaping was retarded in transgenic animals and accuracy was impaired in both the five-choice and the two-choice discrimination tasks, although transgenic mice showed clear evidence for learning. Under conditions of low response requirements, transgenic mice showed increased response and cognitive biases, but reduced perceptual bias, and a behavioural disinhibition, characterized by a reduction in errors of omission, decreased response latencies and increased number of responses during the inter-trial interval. Increasing the response requirement improved performance in transgenic animals as reflected by enhanced accuracy. Moreover, transgenics were less susceptible to the deleterious effects of higher response requirements, as indicated by relatively unaffected bias measures in this group, while bias increased in controls. These results indicate that altered performance in GR-antisense transgenic animals cannot simply be interpreted as a mnemonic deficit, but that altered motivation and enhanced impulsive responding may account for some of these impairments.

Corticotropin-releasing hormone (CRH) has been found to markedly suppress food intake and reduce body weight. However, it still remains to be clarified whether those effects are mediated via either the CRH receptor 1 (CRHR1) or the CRH receptor 2 (CRHR2), or both receptor subtypes. Therefore, we investigated whether CRHR1-deficient mice (CRHR1-KO) show abnormalities in body weight and feeding behavior. CRHR1-KO and wildtype mice showed no difference in the total amount of food intake. However, there was a significant disruption in the circadian distribution of food intake: CRHR1 mutants consumed significantly more food during the light period (p0.01). The normal diurnal pattern could be completely restored by oral administration of corticosterone 21-sulfate (5 mg/l added to the water-based liquid diet). We therefore conclude that in CRHR1-KO mice, the disruption of feeding behavior might be causally related to glucocorticoid deficiency, but that the CRHR1 is not likely to play a critical role in the basal regulation of ingestive behavior.

The ageing process has been shown to have a profound impact on the hypothalamo-neurohypophysial system (HNS) and the hypothalamo-pituitary-adrenocortical (HPA) axis in humans as well as in rodents. Therefore, in this study, the intracerebral and peripheral release patterns of both vasopressin and oxytocin have been studied in aged male Wistar rats under basal conditions and in response to ethologically relevant stressors, using intracerebral microdialysis and chronic blood sampling techniques, respectively. Approximately a twofold higher basal release of arginine vasopressin (AVP) within the hypothalamic paraventricular nucleus (PVN), but not within the supraoptic nucleus (SON), was found in aged rats, whereas basal oxytocin (OXT) release did not differ in comparison with young rats. With increasing age the rise in intra-PVN release of both AVP and OXT was blunted in response to forced swimming. In contrast, the intra-SON release of AVP was unrelated to age. Simultaneously recorded basal secretion of both AVP and OXT from the neurohypophysis into blood was increased in aged rats, with a blunted OXT response to swim stress. Opposed to that, plasma AVP levels remained unchanged in both groups. Basal plasma levels of corticotropin (ACTH) and corticosterone were elevated in aged rats, whereas stress-elicited ACTH and corticosterone responses were indistinguishable. These results indicate age-related changes in the HNS and HPA axis with an enhanced basal activity opposed to a blunted response to stressors with increasing age. The increased basal release of AVP within the PVN suggests a role of intracerebral AVP in age-associated alterations of HPA axis regulation.

Oxytocin is a classic reproductive neuropeptide in the female mammal, but its functions in the brain of the male have been less well studied. As stress induces intracerebral oxytocin release independently of gender, we postulated that central oxytocin may play a role in the control of stress responses. In both male and virgin female rats, oxytocin receptor blockade in the brain by intracerebral infusion of a selective oxytocin antagonist (des Gly-NH2 d(CH2)5 [Tyr(Me)2, Thr4] OVT; 0.75 microgram/5 microliter increased the activity of the hypothalamo-pituitary-adrenal (HPA) axis as indicated by a significantly enhanced basal and stress-induced (exposure to the elevated plus-maze, forced swimming) secretion of corticotropin (ACTH) and corticosterone into blood. The anxiety-related behaviour on the plus-maze was not altered by the antagonist in either males or females. Infusion of the oxytocin antagonist into the hypothalamic paraventricular nucleus by reversed microdialysis resulted in a significant increase in basal release of ACTH in both male and virgin female rats. These results demonstrate a novel, gender-independent physiological function of endogenous brain oxytocin in the regulation of neuroendocrine stress responses. Under basal conditions, the inhibition of the HPA axis occurs, at least in part, within the paraventricular nucleus.

Previous experiments have shown that an exposure to defined stressors activates not only the 'classical' endocrine stress response but also the intrahypothalamic and peripheral release of oxytocin. In the present study we investigated the effects of an acute social defeat experience on the release of oxytocin within the hypothalamic supraoptic nucleus, just outside of the supraoptic nucleus toward the midline within the anterior ventro-lateral part of the hypothalamus, and into plasma of adult male rats. Our results demonstrate that emotional stress triggers the release of oxytocin into the extracellular fluid of both the supraoptic nucleus and the anterior ventro-lateral part of the hypothalamus (up to approximately 320% and 170%, respectively). Interestingly, oxytocin release within the latter brain area, which is likely to originate from axons forming the hypothalamo-neurohypophysial tract, was higher in absolute terms than that within the supraoptic nucleus itself, both under basal conditions and in response to social defeat. In contrast to intrahypothalamic release patterns, plasma oxytocin levels remained virtually unchanged upon stressor exposure. This demonstrates that the release of oxytocin within the hypothalamus is triggered by emotional stress. Furthermore, it indicates that under physiological conditions the release of oxytocin from the dendrites and somata upon axon terminals in the neurohypophysis is differentially regulated. Although not yet studied in detail, it may be hypothesized that the spatial and temporal release pattern of oxytocin is controlled by integrative neuronal networks at different brain levels (including hypothalamus and posterior pituitary) to ensure the appropriate involvement of this peptide in the stress response of the animal.

The aim of the present study was to investigate the physiological significance of the neuropeptide arginine vasopressin (AVP) released within the septum, in the behavioural response of rats to stress. In the first experiment, rats were chronically implanted with a microdialysis probe aimed at the mediolateral or ventral septum to monitor the local release of AVP in response to 10 min of forced swimming in 20 degrees C warm water. Exposure to this stressor caused a significant increase in AVP release in both the mediolateral (174 +/- 21%, P0.01) and ventral septum (220 +/- 33%, P0.01). In contrast, microdialysates collected outside the mediolateral septum or in the lateral ventricle remained at prestress levels throughout the dialysis period. Furthermore, unstressed control animals failed to show significant alterations in vasopressin release in the mediolateral septum. In a second experiment, the introduction of the V1 receptor antagonist d(CH2)5Tyr(Me)AVP into the mediolateral septum via inverse microdialysis concomitant with stressor exposure caused the rats to spend an increased time floating and a reduced time swimming compared to vehicle-treated rats. This effect was acute and also detected 24 h after antagonist administration. Taken together, these findings demonstrate a significant activation of the septal vasopressinergic system in response to swim stress. Furthermore, our data support the view that AVP released within this brain area is involved in the generation of active behavioural strategies aimed at coping with new and challenging situations.

The consequences of glucocorticoid receptor (GR) dysfunction for neuroimmunoendocrine responses to an inflammatory challenge were studied in transgenic mice expressing antisense RNA directed against the GR [GR-impaired (GR-i) mice]. Mice were implanted intraperitoneally with a biotelemetry transmitter to monitor body temperature and locomotion. GR-i mice showed decreased locomotion and body temperature during the dark phase of the diurnal cycle. Intraperitoneal administration of saline caused a rapid increase in body temperature in control mice, which was terminated within 90 min. In GR-i mice, however, body temperature remained elevated for about 6 h. Intraperitoneal injection of endotoxin (10 micrograms/mouse) produced a biphasic fever in control mice. However, in endotoxin-injected GR-i mice, body temperature was not significantly different from their saline-injected controls during the first 6 h. Body temperature then increased and remained elevated during the night period. Both strains showed hypolocomotion after endotoxin. In a second experiment, mice were injected intraperitoneally with saline or endotoxin and killed after 1, 3, 6 or 24 h. In GR-i mice, endotoxin caused an augmented rise in plasma ACTH, but not in corticosterone levels. The endotoxin-induced increase in serum levels of interleukin-1 beta and interleukin-6 was not different between the strains. However, whereas in control mice tumour necrosis factor-alpha levels were below detection at the time points studied, substantial levels of this cytokine were found in the serum of GR-i mice 1 h after endotoxin administration. It may be concluded that life-long impairment of GR evolves in aberrant physiological and humoral responses to an acute inflammatory challenge. These findings expand our understanding about the neuroendocrine and physiological disturbances associated with stress-related disorders.

The neurobiological alterations commonly found in affective disorders (e.g., alterations in the nocturnal sleep profile, dysfunction of the hypothalamic-pituitary-adrenocortical system) gradually recover with improvement of the depressive syndrome. Their persistence during full clinical remission, however, is associated with an increased risk for relapse and, thus may represent trait markers for affective disorders. In order to test this hypothesis, we designed a prospective study in which healthy first-degree relatives (high-risk probands; HRPs; n = 54) of patients with an affective disorder are investigated by means of polysomnography, the combined dexamethasone and corticotropine-releasing hormone (DEX-CRH) test and a variety of psychometric scales. In the present part of the study (index assessment), these HRPs, as a group, showed depression-like alterations in both the sleep pattern and the DEX-CRH-test outcome; furthermore, their psychometric profile was characterized by elevated scores on the scales assessing "rigidity" and "autonomic lability". On a single-case level, 35% of the HRPs were identified as conspicuous (depression-like) in at least two of the three areas investigated. A decision of whether or not this "conspicuousness" indeed represents a trait marker for affective disorders can be reached when the follow-up part of the study has identified those HRPs with their respective premorbide status who have developed an affective disorder in the meantime.

Monocytes express IL-1 and IL-1 receptor antagonist (IL-1Ra) in response to lipopolysaccharide (LPS). IL-1 self-induction contributes to the increase in IL-1 following LPS stimulation. LPS-stimulated IL-1 and IL-1Ra production are inhibited by glucocorticoids. In the present work we examined the regulation of IL-1Ra by Th1 cytokine IFN-gamma, Th2 cytokine IL-4, glucocorticoids and IL-1 in human monocytes. We demonstrate that IL-1 contributes to LPS-induced IL-1 Ra expression as shown by IL-1 blockade in LPS-stimulated monocytes using a specific anti-IL-1beta antibody or recombinant IL-1Ra. Glucocorticoids inhibited IL-1beta-stimulated IL-1Ra mRNA expression and protein production. Glucocorticoids inhibited both IL-1-mediated and non-mediated LPS stimulation of IL-1Ra expression. Both IFN-gamma and IL-4 reversed the inhibitory effect of glucocorticoids on IL-1Ra expression and secretion. The effect of IFN-gamma was blocked by pretreatment of monocytes with an anti-IL-1beta blocking antibody, whereas the effect of IL-4 could not be blocked, demonstrating that IFN-gamma acts through a mechanism dependent on endogenous IL-1 production, whereas IL-4 acts through an IL-1-independent one. Consistent with this finding, IFN-gamma (but not IL-4) failed to reverse the inhibitory effect of glucocorticoids when stimulated by IL-1, and only IL-4 combined with IL-1 showed synergism resulting in an increase in IL-1 Ra production. The differential regulation and involvement of IL-1 in the expression of IL-1Ra by IFN-gamma, IL-4 and glucocorticoids sets the level of monocyte responsiveness during the Th1 or Th2 responses.

Alzheimer's disease (AD) is one of the most frequent causes of dementia in the aged. The elucidation of the pathomechanisms of this neurodegenerative disease with age, as the only risk factor for the majority of cases, is in the centre of the efforts of molecular and cellular neurobiology in preclinical research. Various findings point to the involvement of the amyloid beta protein (A beta) in the pathogenesis and progression of AD. Precipitated A beta aggregates are found in the brain of AD patients post mortem in the so-called plaques, a major histopathological hallmark of this progressive destructive disease. A beta can be toxic to cultivated neuronal cells only in its aggregated fibril form. After interaction with the neuronal cell membrane, these aggregates can induce intracellular oxidative events and can lead to the release of so-called free radicals. This is just one important finding for the involvement of oxidative events in the nerve cell degeneration in AD supporting the oxidative stress hypothesis. Furthermore, different neurochemical methods revealed many additional traits and scars of oxidative reactions in the brain of AD patients. Inflammatory events also seem to take part in the generation of an oxidative environment and therefore in nerve cell death as well. In addition, various age-dependent pathophysiological changes can increase neuronal vulnerability. Different antioxidants can protect cultivated neurons against A beta toxicity, but also against other oxidative stressors relevant to the disease. Besides the classical lipophilic antioxidant vitamin E, the female sex hormone oestrogen could also play an important neuroprotective role as an antioxidant, as was shown recently. Oestrogen, oestrogen derivatives, but also other potential free radical scavengers could block the accumulation of oxidative events on the long run and could, therefore, possibly slow down or prevent progressive nerve cell death of AD, which occurs over decades. If future clinical trials using antioxidants as neuroprotectants in AD would also support the oxidative stress hypothesis of the aetiopathogenesis of AD, antioxidants identified in the laboratory could then find their way more and more into the clinical treatment of Alzheimer's dementia.

Recent research in rats and humans has shown that exogenous progesterone evokes a sleep profile similar to that induced by agonistic modulators of gamma-aminobutyric acid(A) receptors, such as benzodiazepines. This finding suggests the involvement of the neuroactive metabolite of progesterone, allopregnanolone. In the vehicle-controlled study reported here, we assessed the sleep effects of two doses of allopregnanolone (7.5 and 15 mg/kg), mixed with oil, administered intraperitoneally at light onset in 8 rats. The electroencephalogram (EEG) and electromyogram were recorded during the first 6 postinjection hr. Compared with vehicle, both doses of allopregnanolone reduced the latency to non-rapid eye movement sleep (non-REMS) and 15 mg/kg allopregnanolone significantly increased the time spent in pre-REMS, an intermediate state between non-REMS and REMS. Furthermore, allopregnanolone dose-dependently influenced EEG activity during non-REMS and REMS. In non-REMS, EEG activity was decreased in the lower frequencies (or =7 Hz) and enhanced in the frequencies ofor =13 Hz. In REMS, allopregnanolone enhanced high-frequency EEG activity (or =17 Hz). The effects were most pronounced during the first postinjection hours and gradually diminished thereafter. Analysis of the plasma and brain concentrations of allopregnanolone in 45 rats revealed long-lasting increases, which reached maximal levels during the first postinjection hour. The sleep effects of allopregnanolone are very similar to those elicited by larger doses of progesterone, which produce comparable brain levels of allopregnanolone. These data indicate that the steroid allopregnanolone has benzodiazepine-like effects on sleep.

Allopregnanolone, known so far to act as a gamma-aminobutyric acid (GABA) agonist, allosterically decreased the affinity of the GABA agonist muscimol for recombinant alpha1beta2gamma2 and alpha6beta2gamma2 GABA-A receptors. Pregnenolone sulfate, a GABA antagonist, had a similar effect. Both of these neuroactive steroids also reduced the time constant of desensitization (tau) of GABA-induced chloride currents. The effect on desensitization was demonstrated for native receptors of hypothalamic neurons as well as for the recombinant GABA-A receptors. Hence neuroactive steroids may differentially modulate distinct assemblies of GABA-A receptors and thus induce a more subtle modulation of GABAergic synaptic transmission than previously thought possible.

Uber einen langeren Zeitraum nahm man an, periphere endokrine Organe seien die ausschliesliche Syntheseorte fur Steroidhormone. Vor einigen Jahren gelang jedoch der Nachweis, das bestimmte Steroide, die sich strukturchemisch von den klassischen Hormonen unterscheiden, auch im Zentralnervensystem synthetisiert und akkumuliert werden konnen. Diese Steroide erhielten die Bezeichnung Neurosteroide (Baulieu 1991). Zu den wichtigsten Neurosteroiden gehoren Tetrahydrodeoxycorticosteron (THDOC), Allopregnanolon (THP) sowie Pregnanolon. Im Gehirn der Ratte kommen diese endogenen Steroide im nanomolaren Konzentrationsbereich vor und steigen unter experimentellen Stresbedingungen an (Purdy et al. 1991).

Steroide der Nebenniere uben wichtige regulatorische Einflusse sowohl uber den Mineralocorticoid (MR)-wie den Glucocorticoid (GR)-Rezeptor auf das Zentralnervensystem aus [1]. Cortisol, das wichtigste Neben-nierenrinden-Steroid des Menschen, bindet an beide Rezeptoren. Dabei ist nicht klar, uber welchen Rezeptor das zirkadiane Sekretionsmuster des Hypothalamus-Hypophysen-Nebennierenrinden (HHN)-Systems des Menschen und die damit verbundenen physiologischen Einflusse, die u. a. auch im Schlaf-EEG nachweisbar sind, geregelt werden. MR-Antagonisten haben keinen wesentlichen Einflus auf die Hormonsekretion des HHN-Systems. Der GR-Antagonist Mifepriston erzeugt jedoch nach oraler Gabe am Menschen eine deutliche Verstarkung der morgendlichen ACTH- und Cortisolsekretion [2]. Bezuglich des Schlaf-EEGs zeigen nicht-selektive GR-Agonisten wie Cortisol eine Verminderung des REM-Schlafes, wahrend die Einflusse auf den Tiefschlaf (Slow-Wave-Sleep) uneinheitlich sind. Mineralo-corticoid-Rezeptor-Agonisten wie -Antagonisten haben keinen wesentlichen Einflus auf das Schlaf-EEG. Ziel der jetzigen Studie war, MR- und GR-Antagonisten in ihrer Wirkung auf die nachtliche Hormonsekretion und Schlafregulation zu untersuchen. Um Einflusse der endogenen Nebennie-rensteroide zu reduzieren, waren die untersuchten Probanden mit Dexamethason vorbehandelt worden.

The interleukin-1 (IL-1) system is constituted by IL-1 alpha and IL-1 beta and IL-1 receptor antagonist (IL-1ra) that bind the same IL-1 receptors. Hypothalamic-pituitary-adrenal axis hormones are major mediators of the neuroendocrine control over immune function. Corticotropin-releasing hormone (CRH) is produced in peripheral inflammatory sites; its direct effects on inflammatory cytokine synthesis, however, remain unclear. We have studied the effects of CRH (0.1-100 nM) on IL-1 beta and IL-1ra expression by human peripheral monocytes in culture activated with different doses of lipopolysaccharide (LPS). In the absence of LPS, CRH up-regulated IL-1ra and IL-1 beta messenger RNA expression as well as protein synthesis. No significant changes were observed with low doses of LPS (1 ng/ml). In contrast, in combination with high doses of LPS (1 microgram/ml), CRH caused inhibition of IL-1ra and IL-1 beta transcription and secretion. The CRH effects were blocked by its antagonist alpha-helical CRH and mediated by intracellular cAMP. These data indicate that CRH modulates the IL-1 system; depending on the state of activation of the monocyte, CRH exerts an inhibitory control on the activated cell and a stimulatory action on the resting monocyte.

This is the report of a case of a 41-year-old male patient with a rapidly progressing amyotrophic lateral sclerosis (ALS) combined with a severe presenile dementia. Screening for antibody binding on fresh-frozen human brain sections, we found that the patient's cerebrospinal fluid contained antibodies against microglia, the dominant and potentially cytotoxic immuneffector cell of the brain. This finding extends previous observations of CSF autoantibodies against microglia in neurodegenerative diseases. It demonstrates that in addition to antigens of neuronal origin (e.g. anti-Purkinje cell antibodies in paraneoplastic cerebellar dysfunction), glial antigens also appear to be under the surveillance of the CNS and/or the peripheral immune system. Our data provide evidence for a close link between neurodegeneration and the activation of microglia; a possible local antigen production against microglia/brain macrophages, which might regulate the concomitant glial activation in neurodegenerative diseases; and the presence of microglia-binding cerebrospinal antibodies as a marker for the acuity of the disease process underlying the acute deterioration of the neurological and cognitive performance in patients with, e.g., ALS. Future therapeutic strategies could therefore include the modulation of the possibly disease-promoting activation of microglia/brain macrophages.

The present study compares the effects of endotoxin, a key factor in gram-negative bacterial infection, and of corticotropin-releasing hormone (CRH) on ACTH and cortisol secretion in healthy male volunteers in a placebo-controlled design. Endotoxin (isolated from Salmonella abortus equi; 0.4 ng/kg body weight) induced a significantly delayed and prolonged increase of ACTH and cortisol secretion as compared to CRH (100 micrograms), supporting the hypothesis that different intermediate mechanisms are involved (baseline/peak: ACTHEndotoxin vs. ACTHCRH: 140 +/- 40 min vs. 44 +/- 17 min (p0.001); CortisolEndotoxin vs. CortisolCRH: 113 +/- 51 min vs. 66 +/- 31 min (p0.05); peak/baseline: ACTHEndotoxin vs. ACTHCRH: 244 +/- 79 min vs. 200 +/- 25 min (p0.05); CortisolEndotoxin vs. CortisolCRH: 278 +/- 76 min vs. 182 +/- 16 min (p0.001)). Activation of the hypothalamo-pituitary-adrenocortical (HPA) system by endotoxin in men is associated with increased interleukin-6 (peak value: 124 +/- 109 pg/ml) and tumor necrosis factor-alpha (peak value: 69 +/- 53 pg/ml) plasma levels which, probably together with locally produced interleukin-1, stimulate the HPA system both at the hypothalamic and (to a lesser degree) at the pituitary site. Provided that strictly controlled laboratory conditions are applied, the endotoxin challenge test presented here may serve as an appropriate and safe tool to explore an individual's capacity for neuroendocrine adaptation to a bacterial stressor, thus providing information complementary to the CRH test.

The effects of ip endotoxin administration on interleukin 6 (IL6) transcripts in brain and in peripheral tissues of rats were studied together with the effects of this treatment on IL6 and corticosterone concentrations in blood serum. Northern blot analyses showed a rapid increase of IL6 transcripts in spleen, pituitary gland, and adrenals that was paralleled by pronounced elevations in serum IL6 and corticosterone levels. Adrenalectomy further enhanced the induction of IL6 messenger RNA (mRNA) in spleen and pituitary gland and augmented the increase in serum IL6 bioactivity after lipopolysaccharide (LPS) injection. Corticosterone pretreatment (10 mg/kg) completely blocked the increase of IL6 in serum and IL6 mRNA in spleen, adrenals, and hypophysis. In several brain areas, low amounts of IL6 mRNA were detected under basal, noninflammatory conditions, but in response to LPS there was no change in the IL6 mRNA in hippocampus, hypothalamus, and cerebellum. Neither adrenalectomy nor peripheral injections of sublethal LPS doses of up to 10 mg/kg were capable of increasing IL6 mRNA in the hippocampus. The data do not support the hypothesis that central IL6 biosynthesis via transcription of the gene contributes to the endotoxin-mediated activation of the hypothalamic-pituitary-adrenal system. The results, however, clearly demonstrate that LPS-induced IL6 gene expression is subject to glucocorticoid suppression in peripheral tissues.

Most studies of the neuroendocrine effects of corticotropin-releasing factor (CRF) have focused on its role in the regulation of the pituitary-adrenal axis; activation of this axis follows release of the peptide from CRF-containing terminals in the median eminence. However, a sizeable proportion of CRF fibres terminate within the hypothalamus itself, where synaptic contacts with other hypothalamic neuropeptidergic neurons (e.g. gonadotropin-releasing hormone-containing and opioidergic neurons) have been identified. Here, we summarize physiological and pharmacological data which provide insights into the nature and significance of these intrahypothalamic connections. It is now clear that CRF is a potent secretagogue of the three major endogenous opioid peptides (beta-endorphin, Met-enkephalin and dynorphin) and that it stimulates opioidergic neurons tonically. In the case of beta-endorphin, another hypothalamic peptide, arginine vasopressin, appears to be an essential mediator of CRF's effect, suggesting the occurrence of CRF synapses on, or in the vicinity of, vasopressin neurons; morphological support for this assumption is still wanting. Evidence for direct and indirect inhibitory effects of CRF on sexual behaviour and secretion of reproductive hormones is also presented; the indirect pathways include opioidergic neurons. An important conclusion from all these studies is that, in addition to its better known functions in producing adaptive responses during stressful situations, CRF might also contribute to the coordinated functioning of various components of the neuroendocrine system under basal conditions. Although feedback regulation of hypothalamic neuronal activity by peripheral steroids is a well-established tenet of endocrinology, data on modulation of the intrahypothalamic actions of CRF by adrenal and sex steroids are just emerging. Some of these newer findings may be useful in framing questions related to the mechanisms underlying disease states (such as depressive illness) in which CRF has been strongly implicated.

The dibenzothiepine zotepine is a new potential "atypical" neuroleptic exhibiting powerful antiserotonergic and antidopaminergic properties. The efficacy of zotepine was evaluated in a double-blind controlled trial versus the tricyclic neuroleptic perazine in 41 patients suffering mainly from the paranoid-hallucinatory type of schizophrenia. The key outcome variable was the extent of mental disturbance as defined by the total score of the BPRS. Additional outcome variables were GAS and CGI. In addition, adverse reactions and extrapyramidal side effects were assessed according to the FSUCL scale and the Gerlach and AIMS rating scale, respectively. Additional variables recorded were blood pressure, heart rate and routine laboratory parameters as well as electrocardiogram and electroencephalogram. In the first two days, standard equivalent doses of both drugs were administered. Thereafter, doses were administered as required. The efficacy of both substances was compared after 7, 14 and 28 days of treatment. Both drugs showed a similar antipsychotic efficacy. Under zotepine treatment a 55% improvement of the BPRS total score was observed while perazine led to a 41% BPRS score reduction. After 7 days the zotepine group was significantly more improved than the perazine group, possibly due to a dosing effect in the perazine group. In the zotepine group, fewer adverse reactions and a better benefit/risk index were observed although the differences between the two treatment groups did not reach levels of statistical significance. There were no drug-specific abnormal laboratory findings. Thus, in the present study there was no significant difference between zotepine and perazine with respect to antipsychotic efficacy and side-effect rates. However, zotepine showed a trend to a better benefit/risk index at the end of treatment.

The effects of hypnotics on descriptive and functional aspects of electrophysiological sleep parameters are assessed in this report. Because of the arbitrary definition of some of the criteria underlying the conventional sleep stage scoring procedure, computer-aided methods of EEG analysis have become increasingly important for recording and interpreting pharmacological effects on sleep. Of particular interest are the changes of EEG slow-wave activity, since this parameter varies as a function of prior sleep and waking. Several types of interaction between hypnotics and sleep regulation are discussed, some recent pharmacological developments are highlighted, and some common problems in clinical trials are specified.

We investigated self-reported sleep quality in a group of 50 patients in different stages of HIV-1 infection by using a standardized questionnaire (Pittsburgh Sleep Quality Index). Alterations of sleep were found to be significantly correlated with the most severe stage of infection in AIDS patients. Analysis of data failed to indicate a significant influence of zidovudine on self-reported sleep quality.

Veranderungen der zentralnervosen serotoninergen Aktivitat, reflektiert sowohl durch Konzentrationsverschiebungen des Transmitters wie durch veranderte Rezeptorbindungsaffinitaten, werden seit mehreren Jahren vermehrt in Zusammenhang mit der Atiologie affektiver Erkrankungen gebracht (zur Ubersicht: Holsboer 1990). Basierend auf Beobachtungen von Verhalten, das in Zusammenhang mit bestimmten Affektstorungen zu bringen ist und welches unter serotoninerger Kontrolle zu stehen scheint, wie Aggressivitat, verminderte Impulskontrolle, psychomotorische Aktivierung, Angst und Suchtabhangigkeitsentwicklung, und auf Grund neurochemischer und neuropathologischer Befunde, wurde analog der Noradrenalinhypothese eine Serotoninhypothese affektiver Erkrankungen formuliert. Von besonderem Interesse scheint hierbei zu sein, das es in den letzten Jahren sowohl insbesondere durch Anwendung selektiver Rezeptorliganden als auch durch molekularbiologische Methoden gelungen ist, die Serotoninrezeptoren naher zu charakterisieren und ihre Funktionszusammenhange weiter aufzuklaren. Es ist daher Ziel dieser Ubersicht, die serotoninerge Neurotransmission sowohl auf der Basis neuerer Befunde bezuglich ihrer Pharmakologie als auch mit ihren Interaktionen mit anderen Transmitter- und endokrinen Regulationssystemen zu beschreiben, und auf dieser Grundlage die Befunde bei affektiven Erkrankungen zu diskutieren.

Die wichtigsten Anregungen fur die Kausalforschung affektiver Erkrankungen kamen aus der Neuropharmakologie. Nach der Entdeckung der antidepressiven Wirkung von Imipramin durch den Schweizer Psychiater Kuhn und der Beobachtung, das bei 10–20% aller Patienten, die mit Reserpin behandelt werden, depressive Syndrome entstehen, wurde die Noradrenalin (NA)-Mangelhypothese formuliert. Sie basierte auf pharmakologischen Befunden, nach denen das Antidepressivum Imipramin durch Wiederaufnahmehemmung von NA in die prasynaptische Nervenendigung dessen postsynaptische Bioverfugbarkeit erhoht (Abb. 1). Weiter stutzt sich diese Hypothese auf die pharmakologische Eigenschaft von Reserpin, das die prasynaptischen NA-Vesikel entspeichert und damit nach langerer Anwendung die noradrenerge Neurotransmission vermindert. Das Konzept der NA-Mangelhypothese war von grosem heuristischem Wert und hat verschiedene neurobiologische Richtungen in der Depressionsforschung wesentlich beeinflust.

Summary Endogenous depression (ED) is regarded as a psychiatric disease with a biological pathogenesis. Consequently patients with ED respond favourably to somatic treatment, whereas for non-endogenously depressed patients drug-treatment would be often inappropriate. Until now, psychopathologists have failed to define precisely the endogenous subtype of depression on clinical features alone. It is well established that a subgroup of depressed patients shows hypersecretion of Cortisol and consequently inadequate suppression of Cortisol after a test dose of dexamethasone. This dexamethasone suppression test (DST) was introduced as a laboratory marker, specifically identifying endogenously depressed individuals. This survey illustrates the present dispute about the diagnostic confidence and clinical value of the DST in a psychiatric population, and related biochemical aspects. The following conclusions are stated: (a) use of the DST to validate a theory of nosology is premature, (b) Influence of psychoactive drug medication, diet and weight loss have to be established, (c) Preliminary data suggest that abnormal DST results frequently normalize before clinical recovery and abnormal DST results may be observed before a relapse into depression is clinically apparent. From this it was concluded that the DST might be useful as predictor of clinical outcome, (d) From the association of depressive episodes with disinhibited HPA-activity, a causative role of corticotropin and glucocorticoids in the development of psychiatric illness can be hypothesized. Beside some pharmacological data no supportive evidence for this hypothesis is available, (e) MultiSteroid analysis after dexamethasone has provided promising results indicating increased sensitivity of the test when based upon cortisol/11-deoxycortisol ratios and disturbed mineralocorticosteroid secretion in endogenously depressed patients.