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P Gass

Publications and source records attributed to P Gass.

At least 19 recordsLinked to original sources
PubMed2007

[Multiaxial classification of stalking. Guidelines for the assessment of criminal liability and prognosis].

Stalking is a widespread phenomenon describing a pattern of intrusive and threatening behaviour that leads to the victim's perception of being harassed and of him or her being rendered fearful. Physical assault and even homicide may occur in the context of stalking. Anglo-Saxon studies have revealed a lifetime prevalence of being a victim of stalking ranging from 4-7% in men and 12-17% in women. Recently, these rates have been confirmed by the first community based study carried out in Germany. As a stalker can have a number of victims during his or her lifetime, the prevalence of stalkers may be less than this, although at present data for this are lacking. Although the phenomenology of stalking appears to be rather homogenous, fairly distinct stalker typologies and perpetrator-victim relationships have to be considered. Requests for psychiatric and forensic assessment of stalkers are increasing. According to the German penal code, psychiatrists must provide expert opinion on criminal responsibility and the placement of stalkers. So far, all typologies of stalkers refer to the Anglo-Saxon cultural background and do not consider the special needs of German forensic psychiatry. In particular, the psychopathological dimension is widely neglected in common typologies. The present paper proposes a multiaxial typology of stalking that considers the psychopathological dimension, the relationship between stalker and victim and motivational aspects. Consequences for the forensic psychiatric assessment according to section 20, 21 StGB are outlined. It should be pointed out that stalking is not a new diagnostic category, but only involves, at a descriptive level, deviation from a normal behavioural pattern. The central components of the forensic psychiatric assessment remain the known diagnostic categories, the effects of which on behaviour can be analysed.

Crime Victims↗
PubMed2006

Differential regulation of nerve growth factor and brain-derived neurotrophic factor in a mouse model of learned helplessness.

Stress-induced helplessness in rodents constitutes a well-defined model to investigate neurobiological mechanisms of depression. Neurotrophins like nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) have both been shown to be involved in neurobiological changes of physiological and pathological reactions to stress. In this study we investigated NGF and BDNF protein levels in the frontal cortex and hippocampus in mice treated with an established model of inducible helplessness via electric footshocks compared to untreated controls at various times (0 h up to 14 days after treatment). NGF levels were transiently decreased by one forth in the frontal cortex of shocked mice at 6 h after the stress treatment, whereas BDNF levels remained unchanged in the brain areas investigated throughout the time course. In addition, frontal cortex BDNF levels showed a significantly higher concentration in the right compared to the left hemisphere (up to 3-fold). This effect was detectable independently of treatment, namely in shocked and control mice at any time point measured. In conclusion, a transient decrease of frontal NGF constitutes the most striking correlate of neurobiological changes in this animal model of stress-induced change of behaviour. Interhemispherical differences of BDNF content in the frontal cortex are a new finding that might reflect intracerebral side dominance. Thus, subsequent studies of frontal cortex BDNF expression should carefully consider an interhemispherical variance to avoid misinterpretation.

Animals↗
PubMed2006

[Stalking--what does the family doctor need to know?].

Stalking is a widespread phenomenon, which for the stalked person is associated with a not inconsiderable risk of becoming the victim of an act of violence. Furthermore, stalked persons may develop significant psychological problems, and therefore often seek out a doctor as their first contact. Another reason for this is the still unsatisfactory legal situation and widespread ignorance of the stalking problem on the part of the police and the courts. In the light of the above, it is of great importance that the physician should thoroughly familiarize himself with the problems associated with stalking.

Aggression↗
PubMed2006

Age-related alterations in hippocampal spines and deficiencies in spatial memory in mice.

Alterations in neuronal morphology occur in the brain during normal aging, but vary depending on neuronal cell types and brain regions. Such alterations have been related to memory and cognitive impairment. Changes in hippocampal spine densities are thought to represent a morphological correlate of altered brain functions associated with hippocampal-dependent learning and memory. We therefore have analyzed the impact of aging on different hippocampal-dependent learning tasks and on changes in dendritic spines of CA1 hippocampal and dentate gyrus neurons by analyzing adult (6-7 months) and aged (21-22 months) C57/Bl6 mice. We found a significant decrease in spine numbers of basal CA1 dendrites and decreases in spine length of apical dendrites of CA1 and dentate gyrus neurons. Furthermore, aged mice exhibited significant deficits in hippocampus-dependent learning tasks, such as the probe trial of the Morris water maze and T maze learning. Given the fact that there is no neuronal loss in the hippocampus in aged mice (von Bohlen und Halbach and Unsicker [2002] Eur. J. Neurosci. 16:2434-2440), we suggest that the memory and cognitive decline in the context of aging may be accompanied by rather subtle anatomical changes, such as numbers and morphology of dendritic spines.

Aging↗
PubMed2005

Learned helplessness: validity and reliability of depressive-like states in mice.

The learned helplessness paradigm is a depression model in which animals are exposed to unpredictable and uncontrollable stress, e.g. electroshocks, and subsequently develop coping deficits for aversive but escapable situations (J.B. Overmier, M.E. Seligman, Effects of inescapable shock upon subsequent escape and avoidance responding, J. Comp. Physiol. Psychol. 63 (1967) 28-33 ). It represents a model with good similarity to the symptoms of depression, construct, and predictive validity in rats. Despite an increased need to investigate emotional, in particular depression-like behaviors in transgenic mice, so far only a few studies have been published using the learned helplessness paradigm. One reason may be the fact that-in contrast to rats (B. Vollmayr, F.A. Henn, Learned helplessness in the rat: improvements in validity and reliability, Brain Res. Brain Res. Protoc. 8 (2001) 1-7)--there is no generally accepted learned helplessness protocol available for mice. This prompted us to develop a reliable helplessness procedure in C57BL/6N mice, to exclude possible artifacts, and to establish a protocol, which yields a consistent fraction of helpless mice following the shock exposure. Furthermore, we validated this protocol pharmacologically using the tricyclic antidepressant imipramine. Here, we present a mouse model with good face and predictive validity that can be used for transgenic, behavioral, and pharmacological studies.

Animals↗
PubMed2005

mPer1 and mPer2 mutant mice show regular spatial and contextual learning in standardized tests for hippocampus-dependent learning.

Learning and memory, like most physiological processes, seem to be under the control of circadian rhythm. The recently cloned mPer1 and mPer2 genes play an important role in the regulation of the circadian rhythm. In this study, we tested mPer1 and mPer2 mutant mice in two different learning and memory paradigms, a water-maze place navigation task and contextual fear conditioning. In both learning tests, the hippocampus is critically involved. None of these learning types were affected by the mutations, suggesting that mPer1 and mPer2 do not play a major role in the regulation of hippocampus-dependent learning and memory.

Animals↗
PubMed2005

Olfactory bulbectomy in mice induces alterations in exploratory behavior.

The olfactory bulbectomy syndrome is thought to represent a rodent model for psychomotor agitated depression. While this model has been extensively characterized in rats, fewer studies have been conducted with mice. Therefore, the present study aimed at extending the characterization of the OBX-induced behavioral syndrome in mice, using tests like open field, novel object exploration, novel cage and T-maze learning. OBX mice exhibited hyperactivity in a brightly illuminated open field, and also in a novel home cage as well as in the T-maze. Furthermore, OBX mice demonstrated increased exploratory behavior in the novel object test and in the T-maze. The complex alterations described here with respect to locomotion and exploration are robust and can be achieved by relatively simple test procedures. The extended behavioral characterization of the murine OBX model may contribute in particular to the increasing need to test transgenic mice for the presence of depression-like behaviors.

Analysis of Variance↗
PubMed2005

[Changes in the G-DRG System from 2003 to 2005 in Ophthalmology--Ophthalmologic G-DRG 2003 to 2005].

BACKGROUND: The objective of the study was to illustrate the effect of the extensive changes of the German DRG System on reimbursement of clinical ophthalmology during the years 2003, 2004 and 2005. METHODS: All ophthalmologic patients treated as in-patients at the Department of Ophthalmology at the University Munich during the year 2003 served as a reference data basis. By means of appropriate software those cases were then re-grouped according to the G-DRG classification of the years 2003, 2004 and 2005. This resulted in different reimbursements caused only by system changes for an exemplary hospital of maximum medical care. In addition, the same calculations were performed for four virtual, typical clinics based on the calculation data of the "Institut für Entgeltsysteme (InEK)". For those four clinics it was assumed that 80 % of the cases came from one of the subspecialties retina, glaucoma, cataract or strabismus surgery. RESULTS: Changes in the G-DRG system caused the sample hospital of maximum care to loose 8.5 % case mix index (CMI) during the period of 2003 to 2005. For three of the four virtual, typical ophthalmological clinics the theoretic reimbursement conditions also deteriorated: retina surgery -- 10.6 %, glaucoma surgery - 15.8 % and cataract surgery -- 17.9 % CMI. Only strabismus surgery showed an increase of + 5.6 % in CMI during the period examined. CONCLUSION: Over the years 2003 to 2005 the CMI clearly deteriorated for many ophthalmological subspecialties given otherwise identical conditions. To calculate the changes specifically for an individual hospital, the individual base rates have to be considered.

Computer Simulation↗
PubMed2005

[Psychiatric significance of stalking].

AIMS: To provide an overview on the psychiatric significance of stalking and the implications for the health care system. RESULTS: Stalking is a widespread phenomenon and can result in significant health care problems. CONCLUSION: In the future physicians will have to deal with this problem in a professional manner.

Crime↗
PubMed2004

Differential expression of glutamate transporters EAAT1 and EAAT2 in mice deficient for PACAP-type I receptor.

Pituitary adenylate cyclase-activating polypeptide (PACAP) modulates glutamatergic neurotransmission and induces the expression of glutamate transporters EAAT1 and EAAT2 in newborn mouse astroglial cell cultures. Since nanomolar concentrations of PACAP exert this effect, signal transduction via the high affinity PACAP-type I-receptor PAC1 was assumed. To test this hypothesis and to assess the importance of PAC1-signalling in vivo, we analyzed glutamate transporter expression in mice with a PAC1 knockout. EAAT1 and EAAT2 expression was investigated in the hippocampus and the cerebral cortex of PAC1 mutant mice and wildtype littermates by semiquantitative in-situ-hybridization. PAC1-knockout mice show a subtle but significant reduction of EAAT1 expression in the dentate gyrus. In contrast, reduced expression levels of EAAT1 in the cerebral cortex did not reach statistical significance and EAAT2 expression was unchanged in CA3 and cerebral cortex of PAC1 mutant mice. Our data confirm the previously reported in-vitro-regulation of EAAT1 in the adult nervous system in vivo. EAAT2 expression, however, is unchanged in PAC1 knockout mice, most likely due to counterbalancing factors.

Amino Acid Transport System X-AG↗
PubMed2004

[Homogeneity of G-DRGs in ophthalmology].

BACKGROUND: Since the year 2004 hospitals in Germany are obliged to participate in a payment system based on diagnosis-related groups (DRG), which bases hospital reimbursement on the diagnosis and treatment of patients. The aim of this study was to analyze the data of the first German national hospital cost data calculation for their homogeneity. METHODS: The cases at the LMU hospital in Munich were calculated analogous to the national hospital cost data calculation for a period of 7 months. These exemplary data were then analyzed in detail for homogeneity. RESULTS: For many DRGs, the numbers of cases in the analysis were within a range similar to those in the official nationwide calculation. The costs and lengths of stay were similar to those of the official national calculation. CONCLUSIONS: Many ophthalmologic DRGs are quite inhomogeneous necessitating regrouping to avoid false incentives. For cases with high complexity the current system may lead to cost deficits especially for hospitals providing maximum care.

Analysis of Variance↗
PubMed2003

Neurobehavioral effects of alcohol in AMPA receptor subunit (GluR1) deficient mice.

Of the ionotropic glutamatergic receptors, the NMDA receptor is clearly implicated in the acute and chronic effects of ethanol; however, the role of the AMPA receptor in mediating the effects of ethanol in vivo is as yet unclear. Using mice deficient in the AMPA receptor subunit GluR1 (GluR1-/- mice), we investigated whether the AMPA receptor had a significant role in mediating the effects of ethanol. GluR1-/- mice showed greater locomotor activity in a novel environment, but by the fifth day of repeated testing their activity was the same as that of wild-type mice. In contrast to their enhanced locomotor activity, on an accelerating rotarod GluR1-/- mice performed consistently worse than wild-types. With regard to the effects of ethanol on motor responses, GluR1-/- mice did not differ significantly from wild-type mice in ethanol's sedative or incoordinating effects. However, the GluR1-/- mice were insensitive to the hypothermic effects of a hypnotic dose of ethanol in contrast to wild-types; this effect was dissociable from the hypnotic effects of ethanol. Further, tolerance to ethanol developed equally for GluR1-/- mice versus wild-type mice. In terms of alcohol drinking behavior, compared to wild-types, GluR1-/- mice differed neither in the acquisition of voluntary ethanol consumption nor in stress-induced ethanol drinking, nor in the expression of an alcohol deprivation effect (ADE) which is used as a model of relapse-like drinking behavior. In summary, although the loss of a hypothermic effect of ethanol in GluR1-/- mice indicates a critical role for the AMPA receptors in this effect, the GluR1 subunit of the AMPA receptor does not seem to play a critical role in the etiology of alcohol dependence. However, changes observed in activity patterns may be related to the putative role of AMPA receptors in attention deficit hyperactivity disorder.

Alcohol Drinking↗
PubMed2003

Memory retrieval after contextual fear conditioning induces c-Fos and JunB expression in CA1 hippocampus.

Using specific polyclonal antisera against c-Fos, JunB, c-Jun and JunD, we tried to identify the candidate transcription factors of the immediate early gene family which may contribute to the molecular processes during contextual memory reconsolidation. For that purpose we analyzed the expression of these proteins in the hippocampus after contextual memory retrieval in a mouse model of fear conditioning. A single exposure to a foot shock of 0.8 mA was sufficient to induce robust contextual fear conditioning in C57BI/6N mice. In these mice context dependent memory retrieval evoked a marked induction of c-Fos and JunB, but not of c-Jun and JunD, in pyramidal CA1 neurons of the dorsal hippocampus. In contrast, mice exposed and re-exposed only to the context, without foot shock, did not show behavioral signs of contextual fear conditioning and exhibited significantly less expression of c-Fos and JunB in CA1 neurons. Mice which received a foot shock but were not re-exposed to the context revealed no immediate early gene induction. These results demonstrate that contextual memory retrieval is associated with de novo synthesis of specific members of the Fos/Jun transcription factor family. Therefore we suggest that these genes may contribute to plasticity and reconsolidation accompanying the retrieval process. The specific activation of CA1 neurons during the retrieval of contextual fear associations supports the postulated concept of a mnemonic role of this hippocampal subsector during the retrieval of contextual informations.

Animals↗
PubMed2002

[Stalking--from psychoterror to murder].

Stalking is a widespread phenomenon describing a pattern of intrusive and threatening behavior that leads to the victim's perception of being harrassed and rendered afraid. This paper summarizes relevant aspects of the current stalking concept and reviews its historical development. Furthermore, different typologies of stalking behavior, associated psychiatric diagnoses, frequency and demographic data, therapeutic approaches, and the psychomedical effect on victims are described and discussed. Stalking is not restricted to celebrities but can affect everybody. Members of the medical profession and other socially exposed people are especially potential victims of stalkers. Therefore, information on this topic is necessary in order to deal with it in a professional manner.

Aggression↗
PubMed2001

Impairment of mossy fiber long-term potentiation and associative learning in pituitary adenylate cyclase activating polypeptide type I receptor-deficient mice.

The pituitary adenylate cyclase activating polypeptide (PACAP) type I receptor (PAC1) is a G-protein-coupled receptor binding the strongly conserved neuropeptide PACAP with 1000-fold higher affinity than the related peptide vasoactive intestinal peptide. PAC1-mediated signaling has been implicated in neuronal differentiation and synaptic plasticity. To gain further insight into the biological significance of PAC1-mediated signaling in vivo, we generated two different mutant mouse strains, harboring either a complete or a forebrain-specific inactivation of PAC1. Mutants from both strains show a deficit in contextual fear conditioning, a hippocampus-dependent associative learning paradigm. In sharp contrast, amygdala-dependent cued fear conditioning remains intact. Interestingly, no deficits in other hippocampus-dependent tasks modeling declarative learning such as the Morris water maze or the social transmission of food preference are observed. At the cellular level, the deficit in hippocampus-dependent associative learning is accompanied by an impairment of mossy fiber long-term potentiation (LTP). Because the hippocampal expression of PAC1 is restricted to mossy fiber terminals, we conclude that presynaptic PAC1-mediated signaling at the mossy fiber synapse is involved in both LTP and hippocampus-dependent associative learning.

Animals↗
PubMed2001

The mineralocorticoid receptor expression in the mouse CNS is conserved during development.

Using a specific polyclonal antiserum raised in rabbit against amino acids 1-23 of the mouse mineralocorticoid receptor (MR) we investigated the developmental profile of MR expression in the murine CNS by immunocytochemistry. MR protein appeared first at embryonic day E16.5 in the limbic system, i.e. in the hippocampus and induseum griseum. During development and in adulthood, high levels of MR expression were observed in the limbic system, whereas expression levels detectable in layers II, III, V of the neocortex and in motoneurons of cranial nerves and spinal cord were lower. No MR staining was found in the hypothalamus. Developmental MR expression was restricted to neuronal populations that also express MR protein in the adult CNS, indicating that the MR may fulfill the same functions in neurons during development and in adulthood.

Animals↗
PubMed2001

Mice with targeted mutations of glucocorticoid and mineralocorticoid receptors: models for depression and anxiety?

Impaired corticosteroid receptor signaling is a key mechanism in the pathogenesis of stress-related psychiatric disorders such as depression and anxiety. Since in vivo expression and functional studies of corticosteroid receptors are not feasible in the human central nervous system, such analyses have to be done in animal models. Transgenic mice with mutations of corticosteroid receptors are promising tools, which allow us to investigate the role of these proteins in the pathogenesis of symptoms characteristic for depression and anxiety. This review summarizes the neuroendocrinological and behavioral findings that have been obtained in six different mouse strains with specific mutations that influence the expression or the function of the glucocorticoid or the mineralocorticoid receptor (MR). The analyses of these mice helped to define molecular concepts of how corticosteroid receptors regulate the activity of the hypothalamic-pituitary-adrenal (HPA) system. Furthermore, some of these mutant mice exhibited characteristic alterations in behavioral tests for anxiety and despair. However, so far, none of the mouse strains described here can be viewed as an animal model of a specific psychiatric disease defined by common diagnostic criteria. Using high throughput technologies for the identification of genes regulated by glucocorticoid receptor (GR) and MR in brain areas responsible for specific symptoms of stress-related disorders will yield potential new drug targets for the treatment of depression and anxiety.

Animals↗