Sleep recordings in individuals with borderline personality disorder before and after trauma therapy.

Most individuals diagnosed with borderline personality disorder (BPD) have been exposed to severe and traumatic stressors and thus frequently present with symptoms of a posttraumatic stress disorder (PTSD). Severe sleep disturbances often accompany these complex cases, but changes of sleep parameters during therapy and the impact of sleep on treatment response have barely been studied. Narrative Exposure Therapy (NET) is an evidence-based approach for the treatment of trauma-related psychological disorders. To investigate the effect of NET on sleep in patients with BPD and comorbid PTSD, we screened 45 inpatients and outpatients who met the inclusion criteria of both diagnoses according to DSM-IV and who had a minimum of 2 weeks' stable medication. Patients were allocated to NET (N = 13) or treatment as usual (TAU; N = 8) in blocks. Polysomnographies and psychological questionares were performed before, directly and 6 months after the last therapy session. The aim of this pilot study was to investigate the effectiveness of trauma therapy by NET on sleep quantity (total sleep time) and sleep continuity (sleep efficiency and awakenings) in patients with comorbid BPD and PTSD. Participants of the NET group compared with those who received TAU showed an increased reduction in sleep latency from baseline to the end of therapy and a reduction in arousals over time. Patients with longer pre-treatment total sleep time and pre-treatment REM sleep duration showed a better outcome of NET with respect to PTSD symptoms. NET seems not lead to a change in sleep for the worse during therapy and seems to improve sleep as good as treatment as usual. Furthermore, our results provide evidence of an influence of sleep structure at baseline on treatment success later on.

A bioinformatic assay for pluripotency in human cells.

Pluripotent stem cells (PSCs) are defined by their potential to generate all cell types of an organism. The standard assay for pluripotency of mouse PSCs is cell transmission through the germline, but for human PSCs researchers depend on indirect methods such as differentiation into teratomas in immunodeficient mice. Here we report PluriTest, a robust open-access bioinformatic assay of pluripotency in human cells based on their gene expression profiles.

Declarative memory performance is associated with the number of sleep spindles in elderly women.

OBJECTIVE: Recent evidence suggests that the sleep-dependent consolidation of declarative memory relies on the nonrapid eye movement rather than the rapid eye movement phase of sleep. In addition, it is known that aging is accompanied by changes in sleep and memory processes. Hence, the purpose of this study was to investigate the overnight consolidation of declarative memory in healthy elderly women. SETTING: Sleep laboratory of University. PARTICIPANTS: Nineteen healthy elderly women (age range: 61-74 years). MEASUREMENTS: We used laboratory-based measures of sleep. To test declarative memory, the Rey-Osterrieth Complex Figure Test was performed. RESULTS: Declarative memory performance in elderly women was associated with Stage 2 sleep spindle density. Women characterized by high memory performance exhibited significantly higher numbers of sleep spindles and higher spindle density compared with women with generally low memory performance. CONCLUSION: The data strongly support theories suggesting a link between sleep spindle activity and declarative memory consolidation.

Subthreshold depression in Parkinson's disease.

BACKGROUND: Quality of life in Parkinson patients with subthreshold depression could be improved if the prevalence and symptom profile were better understood. METHODS: Our study used standard DSM-IV and Judd criteria as well as motor, depression, and quality-of-life scales to investigate a sample of 110 nondemented Parkinson patients. This led to formation of nondepressed (48.2%), subthreshold depressed (25.5%), and depressed (26.4%) groups. RESULTS: Quality of life was seen to be significantly lower in subthreshold depressed patients than in the nondepressed, and there were differences in the frequency of depressive symptoms that partially overlapped with nonmotor symptoms of vegetative origin in Parkinson's disease (appetite, sleep disorders). Key measures of depression (diminished interest/pleasure) were more frequent in the depressed group compared with the subthreshold depressed, although the motor functions of these 2 groups did not differ significantly. CONCLUSIONS: The Beck Depression Inventory score ranging from 9 to 15 points differentiates subthreshold depressed from nondepressed and depressed patients best.

Sleep and cognition at baseline and the effects of REM sleep diminution after 1 week of antidepressive treatment in patients with depression.

It has been hypothesized that non-rapid eye movement (NREM) sleep facilitates declarative memory consolidation, and rapid eye movement (REM) sleep is particularly important in promoting procedural learning. The aim of this study was to examine the effects of pharmacological REM sleep suppression on performance in different neuropsychological tasks. For our baseline, we chose 41 moderately depressed patients (age range 19-44 years), who were not taking antidepressants. In the morning after polysomnography, we tested memory recall and cognitive flexibility by assessment of verbal and figural fluency, a shift of attention task and the Trail Making Test B. After recording baseline values, patients were assigned randomly to one of three treatment groups: medication with citalopram; medication with reboxetine; or exclusive treatment with psychotherapy. Retesting took place 1 week after onset of treatment. The main results were: (1) an association of slow-wave sleep with verbal memory performance at baseline; (2) a suppression of REM sleep in patients taking citalopram and reboxetine; (3) no differences regarding neuropsychological performance within the treatment groups; and (4) no association of REM sleep diminution with decreases in memory performance or cognitive flexibility in patients treated with citalopram or reboxetine. In line with other studies, our results suggest that there are no negative effects of a decrease in REM sleep on memory performance in patients taking antidepressants.

REM density is associated with treatment response in major depression: Antidepressant pharmacotherapy vs. psychotherapy.

Major depression is one of the most common psychiatric illnesses. Interestingly, a few studies have indicated the existence of depression subgroups, which respond differently to the available treatment options. Previously, sleep abnormalities have been suggested to indicate amenability to different treatment regimens. Thereby, especially REM-sleep parameters seem to play a prominent role, and REM-sleep dysregulation has been repeatedly discussed as a potential endophenotype of depression. With that said, estimating therapy outcome in order to choose the best line of treatment is of utmost importance to patients suffering from depression. The present study looks deeper into these clues by investigating the capability of polysomnographic sleep parameters to predict treatment response in depressed patients to either pharmacotherapy or psychotherapy. Moderately to severely depressed patients (n = 38) were randomly assigned to either psychotherapy (i.e. interpersonal psychotherapy) or pharmacotherapy (i.e., monotherapy with selective serotonin reuptake inhibitors, SSRI, or selective serotonin noradrenalin reuptake inhibitors, SSNRI). Prior to treatment, all patients underwent polysomnography in the sleep laboratory. After treatment, responders and non-responders of both treatment groups were compared regarding their baseline sleep parameters. Higher baseline REM density, i.e. the amount of rapid eye movements during REM sleep, predicted better response to antidepressant pharmacotherapy. In the psychotherapy group, the effect seemed reversed but was not statistically significant. No other sleep parameter predicted treatment response. Our findings support the notion that REM-sleep dysregulation is indeed indicative of a distinct endophenotype of depression and that pharmacotherapy with SSRI/SSNRI might be superior to psychotherapy in these patients.

The cross-sectional GRAS sample: a comprehensive phenotypical data collection of schizophrenic patients.

BACKGROUND: Schizophrenia is the collective term for an exclusively clinically diagnosed, heterogeneous group of mental disorders with still obscure biological roots. Based on the assumption that valuable information about relevant genetic and environmental disease mechanisms can be obtained by association studies on patient cohorts of ≥ 1000 patients, if performed on detailed clinical datasets and quantifiable biological readouts, we generated a new schizophrenia data base, the GRAS (Göttingen Research Association for Schizophrenia) data collection. GRAS is the necessary ground to study genetic causes of the schizophrenic phenotype in a 'phenotype-based genetic association study' (PGAS). This approach is different from and complementary to the genome-wide association studies (GWAS) on schizophrenia. METHODS: For this purpose, 1085 patients were recruited between 2005 and 2010 by an invariable team of traveling investigators in a cross-sectional field study that comprised 23 German psychiatric hospitals. Additionally, chart records and discharge letters of all patients were collected. RESULTS: The corresponding dataset extracted and presented in form of an overview here, comprises biographic information, disease history, medication including side effects, and results of comprehensive cross-sectional psychopathological, neuropsychological, and neurological examinations. With >3000 data points per schizophrenic subject, this data base of living patients, who are also accessible for follow-up studies, provides a wide-ranging and standardized phenotype characterization of as yet unprecedented detail. CONCLUSIONS: The GRAS data base will serve as prerequisite for PGAS, a novel approach to better understanding 'the schizophrenias' through exploring the contribution of genetic variation to the schizophrenic phenotypes.

A flow-cytometric method to investigate glutamate-receptor-sensitivity in whole blood platelets - results from healthy controls and patients with schizophrenia.

Hypofunction of glutamate receptors may contribute to the symptoms of schizophrenia. Human platelets express glutamate receptors and can serve as peripheral surrogate model for neuronal cells. Aim of this study was to establish a fast and sensitive flow-cytometric method to determine the glutamate-dependent kinetics of intracellular calcium ([Ca++]i) mobilization in platelets of schizophrenic patients. Glutamate stimulated [Ca++]i response was measured with a flow-cytometer in anti-CD-41a-labelled whole blood platelets of treated schizophrenic patients (n=18) and controls (n=18). In two control experiments the NMDA-receptor antagonist MK-801 and the dopamine antagonist amisulpride, respectively, were added to probes from healthy subjects. Stimulation with glutamate led dose-dependently to a mobilization of [Ca++]i in both healthy controls and patients. This effect was significantly reduced in patients. In vitro NMDA-antagonism inhibited the glutamate response, whereas dopamine-antagonism had no effect. Our flow-cytometric method allows to measure glutamate-receptor mediated [Ca++]i response in whole blood platelets, without requiring platelet rich preparations. The reduced glutamate-response in the patients was not explained by a direct inhibitory treatment effect. However, further studies with drug naive patients will be necessary to find out whether or not the observed hypoglutamergic function of platelets is endogenous to the disorder.

Changes in CREB phosphorylation and BDNF plasma levels during psychotherapy of depression.

BACKGROUND: The cyclic adenosine monophosphate response element-binding proteins (CREB) and their interaction with brain-derived neurotrophic factor (BDNF) are essential elements in signal transduction pathways important for cellular resilience and neuroplasticity. They play a decisive role in the concept of altered neuroplasticity in major depression. We have previously demonstrated that the increase in phosphorylated CREB (pCREB) in T lymphocytes is significantly associated with clinical improvement in patients treated with antidepressants. In the present study, we focused on patients treated only with psychotherapy to exclude direct pharmacological actions. In addition to pCREB, we also measured the BDNF plasma levels. METHODS: pCREB in T lymphocytes was determined by Western blot; the BDNF plasma levels with solid-phase ELISA. Psychopathology was evaluated with the Hamilton Rating Scale for Depression (HAMD). Thirty patients meeting DSM-IV criteria for major depressive episodes (MDE) were recruited into this 6-week study. They received interpersonal psychotherapy (IPT) twice weekly. RESULTS: After 6 weeks of IPT, 17 patients responded (reduction of > or =50% of baseline HAMD); after 1 week of treatment pCREB increased significantly compared to the nonresponder group. Measurement of the BDNF plasma levels revealed no differences between the responder and nonresponder groups. Furthermore, the correlations between BDNF plasma levels and pCREB were not significant. CONCLUSIONS: The early increase in pCREB is related to treatment response and does not depend on pharmacological interventions or BDNF plasma levels. For the first time, cellular biological markers could be associated with response to psychotherapy.

Delay of gratification and executive performance in individuals with schizophrenia: putative role for eating behavior and body weight regulation.

OBJECTIVE: Impairment in executive functions and disturbed weight regulation are common features in individuals with schizophrenia on antipsychotics. Still, the clinical management of weight gain, including educational programs, is insufficient. Therefore, we hypothesized that distinct executive impairment is associated with the inability to self-control food intake. METHOD: In the present study we investigated the performance in a paradigm analyzing the executive subfunction "delay of gratification" in individuals with schizophrenia (n=29) compared with controls (n=23) and the interrelationship between delay of gratification, overall executive functioning, reported eating behavior and the BMI. We applied a board-game paradigm to operationalize delay of gratification: on designated fields individuals need to decide about a small amount of immediate reinforcement versus double the amount in the end. Appetite and eating behavior were assessed by self-report scales, executive functioning by BADS. RESULTS: We found that the patients performed significantly worse in our paradigm and that this is associated with lower executive functioning. However, the interrelationship between all parameters is complex: there is a significant positive correlation between the reported perceived appetite and executive functioning whereas the reported restrained eating behavior, significantly more frequent in patients, is correlated with low executive functioning and high disinhibition in eating situations. CONCLUSIONS: We conclude that executive functions are necessary to successfully manage eating behavior. Thus, better understanding of the cognitive mechanisms might help to support the patients more efficiently in their tough job to keep control.

Visual declarative memory is associated with non-rapid eye movement sleep and sleep cycles in patients with chronic non-restorative sleep.

OBJECTIVE: Sleep contributes to processes of memory, but many questions still remain open. The aim of this study was to test the role of different aspects of sleep for memory performance in a group of patients with chronic non-restorative sleep. METHODS: Forty-two consecutive patients (mean age 40.3 years; 31 women) with non-restorative sleep were included. All subjects underwent polysomnography for diagnostic reasons and obtained the following diagnoses (International Classification of Sleep Disorders, ICSD): psychophysiological or idiopathic insomnia (N=18), paradoxical insomnia (N=13), mild hypersomnia (N=6), and dysthymic disorder (N=5). Patients with sleep-related breathing disorders or restless legs were not included. Prior to polysomnography on the second night and the next morning, neuropsychological tests were performed. Declarative memory was tested by the Rey-Osterrieth Complex Figure Test and a paired associative word list. Procedural learning was assessed by a mirror-tracing skill. RESULTS: Visual declarative memory performance was significantly associated with total sleep time, sleep efficiency, duration of non-rapid eye movement (NREM) sleep and number of NREM-REM sleep cycles, but not with specific measures of REM sleep or slow wave sleep. CONCLUSIONS: Further indications of a role of sleep, and in particular of NREM sleep and sleep organization, for visual declarative memory were found.

Kiel psychotherapy project for violent offenders Towards empirically based forensic psychotherapy -- disturbance profiles and risk of recidivism among incarcerated offenders in a German prison.

This study reports on a psychotherapy project for violent offenders. The project was established at a German prison by the Psychiatric and Psychotherapeutic Department at the University of Kiel. The overall aim of this project is to develop a scientifically based psychotherapy programme for violent offenders. As a first step the project's systematic initial diagnostic procedures are presented. These procedures are carried out when new prisoners join the project to provide an empirical basis for the planning of therapy. Data are presented for the 60 prisoners who have so far taken part. These show high prevalences for some psychiatric disorders, namely substance related disorders (33% dependency, 55% abuse), personality disorders (58% had at least one personality disorder) and psychopathy according to Hare's criteria (13%). The data also indicate that only a basal level of self-motivation existed to take part in psychotherapy (65% precontemplative). It is apparent that violent offenders constitute a heterogeneous group as far as mental disturbances are concerned. The data suggest that a psychotherapy programme for violent offenders needs to include both targeted interventions to raise motivation and, for those with substance-related and/or personality disorders, disturbance-specific interventions.

Case management for the treatment of patients with major depression in general practices--rationale, design and conduct of a cluster randomized controlled trial--PRoMPT (PRimary care Monitoring for depressive Patient's Trial) [ISRCTN66386086]--study protocol.

BACKGROUND: Depression is a disorder with high prevalence in primary health care and a significant burden of illness. The delivery of health care for depression, as well as other chronic illnesses, has been criticized for several reasons and new strategies to address the needs of these illnesses have been advocated. Case management is a patient-centered approach which has shown efficacy in the treatment of depression in highly organized Health Maintenance Organization (HMO) settings and which might also be effective in other, less structured settings. METHODS/DESIGN: PRoMPT (PRimary care Monitoring for depressive Patients Trial) is a cluster randomised controlled trial with General Practice (GP) as the unit of randomisation. The aim of the study is to evaluate a GP applied case-management for patients with major depressive disorder. 70 GPs were randomised either to intervention group or to control group with the control group delivering usual care. Each GP will include 10 patients suffering from major depressive disorder according to the DSM-IV criteria. The intervention group will receive treatment based on standardized guidelines and monthly telephone monitoring from a trained practice nurse. The nurse investigates the patient's status concerning the MDD criteria, his adherence to GPs prescriptions, possible side effects of medication, and treatment goal attainment. The control group receives usual care--including recommended guidelines. Main outcome measure is the cumulative score of the section depressive disorders (PHQ-9) from the German version of the Prime MD Patient Health Questionnaire (PHQ-D). Secondary outcome measures are the Beck-Depression-Inventory, self-reported adherence (adapted from Moriskey) and the SF-36. In addition, data are collected about patients' satisfaction (EUROPEP-tool), medication, health care utilization, comorbidity, suicide attempts and days out of work. The study comprises three assessment times: baseline (T0) , follow-up after 6 months (T1) and follow-up after 12 months (T2). DISCUSSION: Depression is now recognized as a disorder with a high prevalence in primary care but with insufficient treatment response. Case management seems to be a promising intervention which has the potential to bridge the gap of the usually time-limited and fragmented provision of care. Case management has been proven to be effective in several studies but its application in the private general medical practice setting remains unclear.

[Signals for the initiation of structured diagnostic procedures for depression in primary health care. A practice-relevant evaluation of international guidelines]. / Signalsituationen für den Beginn einer strukturierten Depressionsdiagnostik in der Allgemeinarztpraxis--Eine praxis-kritische Einschätzung internationaler Leitlinien.

BACKGROUND AND OBJECTIVES: Almost every tenth patient of a general practitioner (GP) suffers from depression. However, only 20-25% of these patients are correctly diagnosed during a GP consultation. How do international guidelines for depression in primary care initiate structured diagnostic procedures for depression? METHODS: We performed a systematic literature search on guidelines for the diagnosis of depression with focus on primary care. The quality of the guidelines was rated according to base of evidence, existence of pilot studies, data on implementation, presentation and specificity for primary care settings, and conflict of interest. We also screened whether and how the guidelines comment on the initiation of structured diagnostic procedures for depression. RESULTS: Of the 22 identified guidelines, only 15 address primary care. Only 3 of these were tested in pilot studies, 3 provided data on implementation, 9 were evidence-based. The best guideline (6 out of 6 criteria met) is available in Dutch and established for The Netherlands only. We ranked the guidelines from NHG, VHA and ICSI as very good in terms of methodological quality. They present 'red flags' that initiate structured diagnostic procedures by 'opportunistic screening'. This is followed by the application of a self-rating instrument and an ICD-10-based diagnostic checklist identifying up to 98% of all patients with depression in a given consultation time of 10 minutes on average. CONCLUSION: Based on these criteria a national diagnostic depression guideline should, from our point of view, explicitly include keys such as "red flags" for the initiation of structured diagnostic procedures.

Differential effects of fluoxetine and imipramine on the phosphorylation of the transcription factor CREB and cell-viability.

It has been shown that antidepressants increase the expression of CREB (cAMP-response-element-binding-protein) and BDNF (brain derived neurotrophic factor) in vivo. Apparently inconsistent to these survival-promoting properties for many years antidepressants are known to induce apoptosis in various cell types in vitro. In the present study we evaluated if the antidepressants imipramine and fluoxetine are capable to influence the translational expression and phosphorylation of CREB (pCREB) in cells known to be apoptosis-inducible by antidepressants. We therefore used jurkat cells and quantified apoptosis via propidiumiodid-staining and FACS-analysis. CREB-expression and -phosphorylation was quantified via western blot. Both antidepressants induced apoptosis within 24 h. Fluoxetin starts to induce significant apoptosis at a concentration of 20 microM, whereas imipramine at 100 microM. At these concentrations both antidepressants also increased the phosphorylation of CREB within 6 h. But even in concentrations to low to induce apoptosis both antidepressants still increased CREB-phosphorylation. Treating cells with lowest concentrations only imipramine revealed an increase of CREB-phosphorylation after long-time treatment over 3 weeks. In all experiments overall CREB-expression remained unchanged. In conclusion our experiments indicate that antidepressants are capable to increase CREB-phosphorylation without induction of apoptosis depending on concentration and duration of treatment. We further assume that antidepressants induce CREB-phosphorylation via signal transduction pathways that are different from those inducing apoptosis.

Changes in CREB-phosphorylation during recovery from major depression.

For decades psychiatrists have been looking for biological state markers measurable by easy blood test in order to follow up and predict early on treatment response in patients with major depression. In the present study we investigated whether or not measuring CREB (cAMP-response-element-binding-protein) phosphorylation in peripheral blood T lymphocytes is a state marker of treatment response. CREB is an ubiquitous key-element of intracellular signal transduction cascades and its transcriptional activity depends on phosphorylation at Ser-133. Several studies in animals demonstrated that the transcriptional activity of CREB is up-regulated by antidepressant treatment. Therefore, it has been hypothesized that antidepressant treatment exerts its therapeutic effect by this mechanism. In the present study, we investigated CREB-phosphorylation in T-lymphocytes of 20 patients before and in the end of week one and two of either psychopharmacological or psychotherapeutic treatment. After two weeks, 15 patients fulfilled the criteria of treatment response (i.e. 30% reduction in HAMD score compared to baseline), whereas five patients did not. In the end of week two, the responders showed a significant increase in CREB-phosphorylation (P = 0.018) compared to the non-responders. This was true for all patients with either treatment regimen. In conclusion, these results indicate for the first time that the increase in CREB-phosphorylation might be a molecular state marker for the response to antidepressant treatment.

Impairment of visuospatial memory is associated with decreased slow wave sleep in schizophrenia.

Cognitive impairments such as memory deficits and sleep disturbances are common clinical features of schizophrenia. Since sleep plays an important role in consolidation of memory, we hypothesize, that there is an interrelationship between distinct alterations in sleep and memory performance in schizophrenia. We studied 17 patients with schizophrenia on stable antipsychotic medication with amisulpride (age range 22-44 years; 7 women) and 17 healthy controls (matched for age, gender and educational level). Sleep was recorded and scored according to the standard criteria by Rechtschaffen and Kales. Immediately before polysomnography and the morning after we performed neuropsychological tasks including Rey-Osterrieth Complex Figure Test and a test for recall of spatial location for testing aspects of declarative memory and a mirror tracing skill for procedural memory. In comparison to healthy controls, the patients showed a significant increase in sleep onset latency and a significant decrease in sleep efficiency and amount of slow wave sleep (SWS). Furthermore, the patients' performance in recall of the Rey-figure and of spatial location the next morning was significantly impaired. These impairments in the tests for visuospatial memory were positively correlated with reduction in the amount of SWS and in sleep efficiency. These results point to a functional interrelationship between regulation of SWS and performance in visuospatial memory in schizophrenia. If these results of our pilot study hold true, they will allow the development of innovative treatment strategies for neuropsychological deficits in patients with schizophrenia.

Morning headaches in patients with sleep disorders: a systematic polysomnographic study.

OBJECTIVES: Patients with sleep disorders suffer more often from headache after awakening than healthy subjects. However, it still is a matter of controversy whether this applies only to patients with sleep apnea syndrome (SAS) or also to patients with other diagnoses of sleep disorders. METHODS: We asked all patients in our sleep laboratory about the frequency of past headaches and also ascertained the occurrence of morning headaches after awakening in the sleep laboratory. Polysomnographic recordings from nights before morning headache were compared with nights without following headache. Four hundred and thirty-two patients with sleep disorders (age range 18-86 years, 37% women) and 30 healthy subjects (age range 24-55 years, 27% women) participated in this prospective study. RESULTS: The reported frequency of past headaches and the frequency of morning headache in the sleep laboratory were significantly increased in patients with SAS and other sleep disorders compared with healthy subjects. The occurrence of morning headache in the sleep laboratory was associated polysomnographically with a decrease in total sleep time, sleep efficiency and amount of rapid eye movement sleep and with an increase in the wake-time during the preceding night. CONCLUSIONS: We conclude that morning headaches in patients with sleep disorders might be associated with particular disturbances of the preceding night's sleep. We speculate that dysregulation in anatomically identical central regions modulating sleep and nociception might be relevant to morning headache, rather than one particular sleep disorder such as SAS.

Novel object presentation affects sleep-wake behavior in rats.

Sleep is suggested to be crucial for the processing and storage of new information. Several learning tasks have been shown to increase the amount of rapid eye movement sleep (REMS) with its typical theta activity (6-8 Hz) relative to total sleep time. Vice versa, REMS deprivation is able to affect memory consolidation following some, but not all learning tasks. Furthermore, recent studies have shown an increase of spindle activity (12-15 Hz) within the electroencephalogram (EEG) of nonREMS as well. The enhancement of both spindle and theta activity is suggested to serve as background activity for the synchronization of those neuronal pathways that were involved in the registration and, later on, participate in the long-term storage of new information in defined brain regions. In the present study, the presentation of a novel object to rats enhanced the amount of preREMS, an intermediate sleep stage with high spindle activity, within the first 2 h of the subsequent sleeping phase. Four hours later, the amount of REMS was increased as well. However, there were no changes in the EEG power spectra of nonREMS, preREMS and REMS. We therefore hypothesize that the increase of preREMS and REMS amounts and the related spindle and theta activity stand for the processing and storage of new information about the presented novel objects.