Online cognitive behavioral therapy for prolonged grief after traumatic loss: a randomized waitlist-controlled trial.

Prolonged grief disorder, a condition characterized by severe, persistent, and disabling grief, is newly included in ICD-11 and DSM-5-TR. Prolonged grief symptoms can be effectively treated with face-to-face or internet-delivered cognitive behavioral therapy. Traumatic losses may elicit higher prevalence of severe grief reactions. While face-to-face cognitive behavioral therapy appears efficacious in treating prolonged grief symptoms in traumatically bereaved individuals, it is not yet clear if internet-based cognitive behavioral therapy is efficacious for this population. Therefore, we investigated the efficacy of a 12-week internet-delivered cognitive behavioral therapy for people bereaved through traffic accidents in a randomized waitlist-controlled trial (registration number: NL7497, Dutch Trial Register). Forty adults bereaved though a traffic accident were randomized to internet-based cognitive behavioral therapy (n = 19) or a waitlist control condition (n = 21). Prolonged grief, post-traumatic stress, and depression symptoms were assessed at baseline, post-treatment, and 8-week follow-up. Dropout in the treatment condition was relatively high (42%) compared to the control condition (19%). Nevertheless, multilevel analyses showed that internet-based cognitive behavioral therapy strongly reduced prolonged grief, post-traumatic stress, and depression symptoms relative to the control condition at post-treatment and follow-up. We conclude that internet-based cognitive behavioral therapy appears a promising treatment for traumatically bereaved adults.

Assessing DSM-5-TR and ICD-11 prolonged grief disorder in children and adolescents: development of the Traumatic Grief Inventory - Kids - Clinician-Administered.

BACKGROUND: Around 10% of bereaved youths experience symptoms of prolonged grief disorder (PGD). Recently, PGD was included in the two main classification systems for mental disorders: the ICD-11 and DSM-5-TR. Assessing PGD symptoms in youth is currently hindered by the lack of instruments for ICD-11 and DSM-5-TR criteria. To fill this gap, we developed an instrument to assess PGD symptoms in children and adolescents, the Traumatic Grief Inventory - Kids - Clinician-Administered (TGI-K-CA), based on input of grief experts and bereaved children. METHODS: Five experts rated the items on alignment with DSM-TR and ICD-11 PGD symptoms and comprehensibility. The adjusted items were then presented to seventeen bereaved youths (Mdnage = 13.0 years, range = 8-17 years). Using the Three-Step Test Interview (TSTI), children were asked to verbalize their thoughts while answering the items. RESULTS: Issues raised by experts were mostly related to alignment with the DSM-5-TR/ICD-11 symptom, ambiguous formulation of the items, or low comprehensibility for children and adolescents. Items raising fundamental issues according to experts were adjusted. The TSTI showed that children encountered relatively few problems with the items. Frequently reported problems with some of the items (e.g. regarding comprehensibility) led to final adjustments. CONCLUSION: With input from grief experts and bereaved youths, an instrument to assess PGD symptoms as defined in DSM-5-TR and ICD-11 in bereaved youths was finalized. Further quantitative research is currently undertaken to evaluate the instrument's psychometric qualities.

Children with symptoms of Prolonged Grief Disorder (PGD) experience a debilitating longing for and/or preoccupation with a deceased loved one.Assessment of PGD in youth is hindered by the lack of an instrument.With the involvement of grief experts and bereaved youth, the current study developed an instrument that can be used in bereaved children and adolescents.

Self-guided online treatment of disturbed grief, posttraumatic stress, and depression in adults bereaved during the COVID-19 pandemic: A randomized controlled trial.

OBJECTIVE: This randomized-waitlist controlled trial is the first study examining short-term effects of a self-guided online grief-specific cognitive behavioral therapy (CBT) in reducing early persistent complex bereavement disorder (PCBD), posttraumatic stress disorder (PTSD), and depression symptoms in adults bereaved during the COVID-19 pandemic. METHOD: Sixty-five Dutch adults, bereaved at least three months earlier during the pandemic, with clinically-relevant PCBD, PTSD, and/or depression symptoms, were allocated to a treatment (n = 32) or waitlist condition (n = 33). Telephone interviews were conducted to assess PCBD, PTSD, and depression symptoms (using validated instruments) at baseline, post-treatment, and post-waiting period. Participants received an eight-week self-guided online grief-specific CBT including exposure, cognitive restructuring, and behavioral activation assignments. Analyses of covariance were performed. RESULTS: Intention-to-treat analyses indicated that people in the intervention condition showed significantly lower PCBD (d = 0.90), PTSD (d = 0.71), and depression (d = 0.57) symptom-levels post-treatment relative to waitlist controls post-waiting, while taking baseline symptom-levels and use of professional psychological co-intervention into account. CONCLUSIONS: The online CBT proved to be an effective intervention, reducing PCBD, PTSD, and depression symptoms. Pending replication of these findings, early online interventions may be widely implemented in practice to improve treatments for distressed bereaved people.

The mediating role of state anger in the associations between intentions to participate in the criminal trial and psychopathology in traumatically bereaved people.

Victims of crimes have been granted increasing procedural rights to participate in the juridical process since the mid 1990s. However, knowledge about the (anti)-therapeutic effect of participation is limited. We examined the associations between symptom levels of persistent complex bereavement disorder (PCBD), posttraumatic stress disorder (PTSD), and depression and the intention to participate in a criminal trial. Furthermore, we investigated the mediating role of state anger in these associations. People who lost loved ones after a plane disaster with flight MH17 (N = 203) completed questionnaires within three weeks before the start of the criminal trial. Mediation analyses indicated that people, who did not intend to actively participate in the trial by delivering a written or oral victim statement, were less likely to experience anger, which is, in turn, associated with attenuated psychopathology levels. State anger explains 68% of the effect of the intention to exercise the right to speak on PCBD levels. An important limitation is the cross-sectional study design, which precludes conclusions about temporal associations. More research is needed to improve preparation and support of bereaved people when they intend to exercise their victim rights during a criminal trial.

"I lost so much more than my partner" - Bereaved partners' grief experiences following suicide or physician-assisted dying in case of a mental disorder.

BACKGROUND: There is a lack of existing research on grief following the intentional death of people suffering from a mental disorder. Our study aims to provide insight into grief experiences and social reactions of bereaved persons who lost their life partners, who were suffering from a mental disorder, to physician-assisted dying (PAD) or suicide. METHODS: For this mixed-methods research, we conducted a survey and in-depth interviews with 27 persons living in the Netherlands and bereaved by the death of their life partners. The deceased life partners suffered from a mental disorder and had died by physician-assisted dying (n = 12) or suicide (n = 15). Interviews explored grief experiences and social reactions. In the survey we compared self-reported grief reactions of partners bereaved by suicide and PAD using the Grief Experience Questionnaire. RESULTS: Compared to suicide, physician-assisted dying was associated with less severe grief experiences of the bereaved partners. Participants reported that others rarely understood the suffering of their deceased partners and sometimes expected them to justify their partners' death. Following physician-assisted dying, the fact that the partner's euthanasia request was granted, helped others understand that the deceased person's mental suffering had been unbearable and irremediable. Whereas, following suicide, the involvement of the bereaved partners was sometimes the focus of judicial inquiry, especially, if the partner had been present during the death. CONCLUSION: When individuals suffering from a mental disorder die by suicide or PAD, their bereaved partners may experience a lack of understanding from others. Although both ways of dying are considered unnatural, their implications for bereaved partners vary considerably. We propose looking beyond the dichotomy of PAD versus suicide when studying grief following the intentional death of people suffering from a mental disorder, and considering other important aspects, such as expectedness of the death, suffering during it, and partners' presence during the death.

Valid measurement of DSM-5 persistent complex bereavement disorder and DSM-5-TR and ICD-11 prolonged grief disorder: The Traumatic Grief Inventory-Self Report Plus (TGI-SR+).

INTRODUCTION: When grief reactions after bereavement are so intense that they impair daily functioning, a diagnosis of disturbed grief may apply. Slightly differing criteria-sets for disturbed grief are included in the ICD-11, the DSM-5, and its forthcoming text revision, DSM-5-TR. We examined psychometric properties of a new self-report measure, the 22-item Traumatic Grief Inventory-Self Report Plus (TGI-SR+), that assesses these criteria sets for Persistent Complex Bereavement Disorder (PCBD) as per DSM-5, and Prolonged Grief Disorder (PGD) as defined in ICD-11 and DSM-5-TR. MATERIAL AND METHODS: We examined the: i) factor structure, ii) internal consistency, iii) temporal stability, iv) convergent validity, v) known-groups validity, vi) probable caseness, and vii) optimal clinical cut-off scores in two Dutch bereaved samples. Sample 1 consisted of 278 adults, bereaved by various causes. Sample 2 included 270 adults who lost loved ones in a traffic accident. RESULTS: We found support for a 3-factor PCBD model, 1-factor DSM-5-TR model, and 1-factor ICD-11 PGD model. The DSM-5 PCBD, DSM-5-TR PGD, and ICD-11 PGD items demonstrated good internal consistency and temporal stability. Associations between disturbed grief symptoms and posttraumatic stress and depression levels supported convergent validity. Associations between demographic/loss-related variables and disturbed grief symptoms supported known-groups validity. Optimal clinical cut-offs for the TGI-SR+ total score were ≥ 75, ≥71, and ≥ 75 for probable caseness of DSM-5 PCBD, DSM-5-TR PGD, and ICD-11 PGD, respectively. DISCUSSION: While replication of our findings in diverse bereaved samples is needed, we conclude that the TGI-SR+ is a reliable and valid measure to assess symptoms of DSM-5 PCBD, DSM-5-TR PGD, and ICD-11 PGD.

Online treatment of persistent complex bereavement disorder, posttraumatic stress disorder, and depression symptoms in people who lost loved ones during the COVID-19 pandemic: study protocol for a randomized controlled trial and a controlled trial.

Background: Losing a loved one during the COVID-19 pandemic is a potentially traumatic loss that may result in symptoms of persistent complex bereavement disorder (PCBD), posttraumatic stress disorder (PTSD), and depression. To date, grief-specific cognitive-behavioural therapy (CBT) has mostly been delivered through individual face-to-face formats, while studies have shown that online treatment also yields promising results. Offering treatment online is now more than ever relevant during the pan demic and may offer important benefits compared with face-to-face CBT, such as lower costs and higher accessibility. Our expectation is that grief-specific online CBT is effective in reducing PCBD, PTSD, and depression symptoms. Objective: Our aim is to evaluate the short-term and long-term effectiveness of grief-specific online CBT in reducing PCBD, PTSD, and depression symptom-levels for adults who lost a loved one during the COVID-19 pandemic. Method: This study consists of two parts. In part 1, a two-armed (unguided online CBT versus waitlist controls) randomized controlled trial will be conducted. In part 2, a two-armed (guided online CBT versus unguided online CBT) controlled trial will be conducted. Symptoms of PCBD, PTSD, and depression will be assessed via telephone interviews at pre-treatment/pre-waiting period, post-treatment/post-waiting period, and six months post-treatment. Potential participants are people who lost a loved one at least three months earlier during the COVID-19 pandemic with clinically relevant levels of PCBD, PTSD, and/or depression. Analysis of covariance and multilevel modelling will be performed. Discussion: This is one of the first studies examining the effectiveness of online grief-specific CBT. More research is needed before implementing online grief-specific CBT into clinical practice.

Antecedentes: Perder a un ser querido durante la pandemia de COVID-19 es una pérdida potencialmente traumática que puede resultar en síntomas de trastorno de duelo complejo persistente (PCBD en su sigla en inglés), trastorno de estrés postraumático (TEPT) y depresión. Hasta la fecha, la terapia cognitivo-conductual (TCC) específica para el duelo se ha proporcionado principalmente a través de formatos individuales cara a cara, mientras que los estudios han demostrado que el tratamiento en línea también produce resultados prometedores. Ofrecer tratamiento en línea es ahora más relevante que nunca durante la pandemia y puede ofrecer importantes beneficios en comparación con la TCC presencial, como menores costos y mayor accesibilidad. Nuestra expectativa es que la TCC en línea específica para el duelo sea eficaz para reducir el PCBD, el TEPT y los síntomas de depresión.Objetivo: Nuestro objetivo es evaluar la efectividad a corto y largo plazo de la TCC en línea específica para el duelo en la reducción de los niveles de PCBD, TEPT y síntomas de depresión en adultos que perdieron a un ser querido durante la pandemia de COVID-19.Método: Este estudio consta de dos partes. En la parte 1, se llevará a cabo un ensayo controlado aleatorio de dos brazos (TCC en línea no guiado versus controles con la lista de espera). En la parte 2, se llevará a cabo un ensayo controlado de dos brazos (TCC en línea guiada versus TCC en línea no guiada). Los síntomas de PCBD, TEPT y depresión se evaluarán mediante entrevistas telefónicas en el período de pretratamiento/pre-espera, post-tratamiento/post-período de espera y seis meses post-tratamiento. Los participantes potenciales son personas que perdieron a un ser querido al menos tres meses antes durante la pandemia de COVID-19 con niveles clínicamente relevantes de PCBD, TEPT y/o depresión. Se realizarán análisis de covarianza y modelado multinivel.Discusión: Este es uno de los primeros estudios que examinan la efectividad de la TCC en línea específica para el duelo. Se necesita más investigación antes de implementar la TCC en línea específica para el duelo en la práctica clínica.

DSM-5-TR prolonged grief disorder and DSM-5 posttraumatic stress disorder are related, yet distinct: confirmatory factor analyses in traumatically bereaved people.

Background: Prolonged grief disorder (PGD) is newly included in the text revision of the DSM-5 (DSM-5-TR). So far, it is unknown if DSM-5-TR PGD is distinguishable from bereavement-related posttraumatic stress disorder (PTSD). Prior research examining the distinctiveness of PTSD and pathological grief focused on non-traumatic loss samples, used outdated conceptualizations of grief disorders, and has provided mixed results. Objective: In a large sample of traumatically bereaved people, we first evaluated the factor structure of PTSD and PGD separately and then evaluated the factor structure when combining PTSD and PGD symptoms to examine the distinctiveness between the two syndromes. Methods: Self-reported data were used from 468 people bereaved due to the MH17 plane disaster (N = 200) or a traffic accident (N = 268). The 10 DSM-5-TR PGD symptoms were assessed with the Traumatic Grief Inventory-Self Report Plus (TGI-SR+). The 20-item Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5) was used to tap PTSD symptoms. Confirmatory factor analyses were conducted. Results: For PTSD, a seven factor, so-called 'Hybrid' model yielded the best fit. For PGD, a univariate factor model fits the data well. A combined model with PGD items loading on one factor and PTSD items on seven factors (associations between PGD and PTSD subscales r ≥ .50 and ≤.71), plus a higher-order factor (i.e. PTSD factors on a higher-order PTSD factor) (association between higher-order PTSD factor and PGD factor r = .82) exhibited a better fit than a model with all PGD and PTSD symptom loading on a single factor or two factors (i.e. one for PGD and one for PTSD). Conclusions: This is the first study examining the factor structure of DSM-5-TR PGD and DSM-5 PTSD in people confronted with a traumatic loss. The findings provide support that PGD constitutes a syndrome distinguishable from, yet related with, PTSD.

Antecedentes: El trastorno de duelo prolongado (PGD en su sigla en inglés) se incluyó recientemente en la revisión del texto del DSM-5 (DSM-5-TR). Hasta ahora, se desconoce si el PGD del DSM-5-TR se puede distinguir del trastorno de estrés postraumático (TEPT) relacionado con el duelo. Investigaciones anteriores que examinaron el carácter distintivo del trastorno de estrés postraumático y el duelo patológico se centraron en muestras con pérdidas no traumáticas, utilizaron conceptualizaciones obsoletas de los trastornos del duelo y arrojaron resultados mixtos.Objetivo: En una muestra grande de personas en duelo traumático, primero evaluamos la estructura factorial de TEPT y PGD por separado y luego evaluamos la estructura factorial al combinar los síntomas de TEPT y PGD para examinar la distinción entre los dos síndromes.Métodos: Se utilizaron datos autoreportados de 468 personas en duelo debido al desastre del avión MH17 (N = 200) o un accidente de tráfico (N = 268). Los 10 síntomas de PGD del DSM-5-TR se evaluaron con el Inventario de Autoreporte de Duelo Traumático Plus (TGI-SR +). Se utilizó la lista de chequeo de 20 ítems para el trastorno de estrés postraumático para el DSM-5 (PCL-5) para examinar los síntomas del TEPT. Se realizaron análisis factoriales confirmatorios.Resultados: Para el TEPT, un modelo de siete factores, llamado modelo 'híbrido', produjo el mejor ajuste. Para el PGD, un modelo de factor univariado se ajusta bien a los datos. Un modelo combinado con elementos de PGD que cargan en un factor y elementos de TEPT en siete factores (asociaciones entre las subescalas de PGD y TEPT r ≥ 50 y ≤ .71), más un factor de orden superior (es decir, factores de TEPT en un factor de TEPT de orden superior)) (asociación entre el factor TEPT de orden superior y el factor PGD r = .82) mostró un mejor ajuste que un modelo con toda la carga de síntomas de PGD y TEPT en un solo factor o dos factores (es decir, uno para PGD y otro para TEPT).Conclusiones: Este es el primer estudio que examina la estructura factorial del PGD según DSM-5-TR y el TEPT según DSM-5 en personas que enfrentan una pérdida traumática. Los hallazgos respaldan que el PGD constituye un síndrome que se distingue del TEPT, pero que está relacionado con él.

Seroepidemiological studies indicate frequent and repeated exposure to Campylobacter spp. during childhood.

The annual number of episodes of clinical gastroenteritis caused by Campylobacter spp. in The Netherlands is estimated to be 75 000, i.e. once per 200 person life-years. This number is based on extrapolation of culture results from population-based studies. The number of culture-confirmed cases of Campylobacter infection peaks in the first 3 years of life and again between the ages of 20 and 25 years. The seroepidemiology of Campylobacter describes the relationship between age and exposure to Campylobacter and reflects both symptomatic and asymptomatic infections. Using a validated ELISA system, antibodies to Campylobacter were measured in an age-stratified sample (n=456) of the PIENTER serum collection of the Dutch general population. The seroprevalence of Campylobacter IgG antibodies increased with age, reaching almost 100% at age 20 years. Antibody levels steadily increased with age until young adulthood, suggesting repeated exposure to Campylobacter. In conclusion, seroepidemiological data demonstrated repeated exposures to Campylobacter throughout life, most of which do not lead to clinical symptoms. From young adulthood, >95% of the population in The Netherlands had serological evidence for exposure to Campylobacter.

Localization of pre- and postsynaptic cholinergic markers in rodent forebrain: a brief history and comparison of rat and mouse.

Rat and mouse models are widely used for studies in cognition and pathophysiology, among others. Here, we sought to determine to what extent these two model species differ for cholinergic and cholinoceptive features. For this purpose, we focused on cholinergic innervation patterns based on choline acetyltransferase (ChAT) immunostaining, and the expression of muscarinic acetylcholine receptors (mAChRs) detected immunocytochemically. In this brief review we first place cholinergic and cholinoceptive markers in a historic perspective, and then provide an overview of recent publications on cholinergic studies and techniques to provide a literature survey of current research. Next, we compare mouse (C57Bl/J6) and rat (Wistar) cholinergic and cholinoceptive systems simultaneously stained, respectively, for ChAT (analyzed qualitatively) and mAChRs (analyzed qualitatively and quantitatively). In general, the topographic cholinergic innervation patterns of both rodent species are highly comparable, with only considerable (but region specific) differences in number of detectable cholinergic interneurons, which are more numerous in rat. In contrast, immunolabeling for mAChRs, detected by the monoclonal antibody M35, differs markedly in the forebrain between the two species. In mouse brain, basal levels of activated and/or internalized mAChRs (as a consequence of cholinergic neurotransmission) are significantly higher. This suggests a higher cholinergic tone in mouse than rat, and hence the animal model of choice may have consequences for cholinergic drug testing experiments.

Interleukin-6 upregulates neuronal adenosine A1 receptors: implications for neuromodulation and neuroprotection.

The immunological response in the brain is crucial to overcome neuropathological events. Some inflammatory mediators, such as the immunoregulatory cytokine interleukin-6 (IL-6) affect neuromodulation and may also play protective roles against various noxious conditions. However, the fundamental mechanisms underlying the long-term effects of IL-6 in the brain remain unclear. We now report that IL-6 increases the expression and function of the neuronal adenosine A1 receptor, with relevant consequences to synaptic transmission and neuroprotection. IL-6-induced amplification of A1 receptor function enhances the responses to readily released adenosine during hypoxia, enables neuronal rescue from glutamate-induced death, and protects animals from chemically induced convulsing seizures. Taken together, these results suggest that IL-6 minimizes the consequences of excitotoxic episodes on brain function through the enhancement of endogenous adenosinergic signaling.

Validation of an ELISA for the diagnosis of recent Campylobacter infections in Guillain-Barré and reactive arthritis patients.

Weeks or months following Campylobacter infection, a small proportion of infected individuals develop Guillain-Barré syndrome (GBS) or reactive arthritis (ReA). Stool culture for Campylobacter is often negative in these patients, and serology is therefore the method of choice for diagnosing a recent infection with Campylobacter. This study developed a capture ELISA system to detect anti-Campylobacter IgA and IgM antibodies indicative of a recent infection. The sensitivity of the assay was 82.0% in uncomplicated Campylobacter enteritis patients, 96.2% in GBS patients who were culture-positive for Campylobacter, and 93.1% in culture-positive ReA patients, with a specificity of 93.0%. The assay allows identification of Campylobacter infection in patients with post-infectious neurological and rheumatological complications.

Grief shortly after suicide and natural death: a comparative study among spouses and first-degree relatives.

Chronic dysfunction after complicated grief is not rare and emphasizes the need to identify bereaved individuals at risk. Three months following bereavement, self-reported psychiatric and general health of 153 relatives of 74 suicides was worse than of 70 relatives of 39 natural deaths. Moreover, the felt need for professional help was higher among the former, even after adjustment for expectedness of death, sociodemographic differences, and relatives'/spouses' neuroticism. This suggests that suicide-bereaved individuals may constitute a high-risk group of mourners in need of targeted postvention.

Chronic excess of corticosterone increases serotonergic fibre degeneration in aged rats.

Evidence is presented for the potentiating role of corticosterone on axonal degeneration of serotonergic neurones during ageing. Aged rats, 24 months old, were implanted subcutaneously with 2 x 100 mg pellets of corticosterone. Serotonergic and cholinergic (ChAT- and NADPHd-positive) fibre degenerations in the anteroventral thalamic nucleus (AVT) were measured 2 months after corticosterone implantation. Numbers of immunoreactive serotonergic raphe and mesolimbic cholinergic neurones were also quantified. Basal plasma corticosterone and adrenocorticotropin (ACTH) concentrations were assayed at 2, 4, 6, and 8 weeks after implantation in the plasma and at 1, 2, 4 and 6 weeks in urine. The degree of serotonergic fibre aberrations in the AVT increased significantly after corticosterone exposure, while that of ChAT-positive and NADPHd-stained axon aberrations showed a modest but nonsignificant increase. A positive correlation between the magnitudes of serotonergic and cholinergic fibre aberrations appeared in the AVT, but only in the corticosterone-treated rats. The number of serotonin immunopositive neurones in the raphe nuclei after corticosterone decreased marginally, while that of mesopontine ChAT-positive neurones was not influenced. Measurements of basal plasma corticosterone and ACTH, as well as urine corticosterone, revealed that the steroid implantation increased the plasma corticosterone level for at least 4 weeks and decreased ACTH level for at least 6 weeks. By the week 8, the pituitary-adrenal function was apparently restored. However, at sacrifice, both the weight of adrenal glands and that of thymus remained reduced, indicating the long-lasting effects of corticosterone on target tissues. It is concluded that the raphe serotonergic neurones and their projecting fibres are sensitive to corticosterone excess in aged rats and become more vulnerable to degeneration processes than under normal ageing conditions. Cholinergic neurones of brainstem origin, which also express massive NADPHd activity, are more resistant against corticosterone, but their axon degeneration correlates to serotonergic fibre degeneration.

17beta-estradiol enhances cortical cholinergic innervation and preserves synaptic density following excitotoxic lesions to the rat nucleus basalis magnocellularis.

Estradiol exerts beneficial effects on neurodegenerative disorders associated with the decline of cognitive performance. The present study was designed to further investigate the effect of 17beta-estradiol on learning and memory, and to evaluate its neuroprotective action on cholinergic cells of the nucleus basalis magnocellularis, a neural substrate of cognitive performance. Female rats were ovariectomized at an age of 6 months. Three weeks later they received injections of either a mid-physiological dose of 17beta-estradiol or vehicle (oil), every other day for 2 weeks. The effect of estradiol on cognitive performance was tested in two associative learning paradigms. In the two-way active shock avoidance task estradiol-replaced animals learned significantly faster, while in the passive shock avoidance test no differences were observed between the experimental groups. Subsequent unilateral infusion of N-methyl-D-aspartate in the nucleus basalis magnocellularis resulted in a significant loss of cholinergic neurons concomitant with the loss of their fibers invading the somatosensory cortex. Estradiol treatment did not affect the total number of choline-acetyltransferase-immunoreactive neurons and their coexpression of the p75 low-affinity neurotrophin receptor either contralateral or ipsilateral to the lesion. In contrast, cholinergic fiber densities in estradiol-treated animals were greater both in the contralateral and ipsilateral somatosensory cortices as was detected by quantitative choline-acetyltransferase and vesicular acetylcholine transporter immunocytochemistry. However, estradiol treatment did not affect the lesion-induced relative percentage loss of cholinergic fibers. A significant decline of synaptophysin immunoreactivity paralleled the cholinergic damage in the somatosensory cortex of oil-treated animals, whereas an almost complete preservation of synaptic density was determined in estradiol-treated rats. Our results indicate that estradiol treatment enhances the cortical cholinergic innervation but has no rescuing effect on cholinergic nerve cells in the basal forebrain against excitotoxic damage. Nevertheless, estradiol may restore or maintain synaptic density in the cerebral cortex following cholinergic fiber loss. This estradiol effect may outweigh the lack of cellular protection on cholinergic cells at the functional level.

Short-term consequences of N-methyl-D-aspartate excitotoxicity in rat magnocellular nucleus basalis: effects on in vivo labelling of cholinergic neurons.

Cholinergic neurons of the basal forebrain form one of the neuron populations that are susceptible to excitotoxic injury. Whereas neuropharmacological studies have aimed at rescuing cholinergic neurons from acute excitotoxic attacks, the short-term temporal profile of excitotoxic damage to cholinergic nerve cells remains largely elusive. The effects of N-methyl-D-aspartate (NMDA) infusion on cytochemical markers of cholinergic neurons in rat magnocellular nucleus basalis were therefore determined 4, 24 and 48 h post-lesion. Additionally, the influence of excitotoxic damage on the efficacy of in vivo labelling of cholinergic neurons with carbocyanine 3-192IgG was investigated. Carbocyanine 3-192IgG was unilaterally injected in the lateral ventricle. Twenty-four hours later, NMDA (60 nM/microl) was infused in the right magnocellular nucleus basalis, while control lesions were performed contralaterally. Triple immunofluorescence labelling for carbocyanine 3-192IgG, NMDA receptor 2A and B subunits and choline-acetyltransferase (ChAT) was employed to determine temporal changes in NMDA receptor immunoreactivity on cholinergic neurons. The extent of neuronal degeneration was studied by staining with Fluoro-Jade. Moreover, changes in the numbers of ChAT or p75 low-affinity neurotrophin receptor immunoreactive neurons, and the degree of their co-labelling with carbocyanine 3-192IgG were determined in basal forebrain nuclei. The effects of NMDA-induced lesions on cortical projections of cholinergic nucleus basalis neurons were studied by acetylcholinesterase (AChE) histochemistry. Characteristic signs of cellular damage, as indicated by decreased immunoreactivity for NMDA receptors, ChAT and p75 low-affinity neurotrophin receptors, were already detected at the shortest post-lesion interval investigated. Fluoro-Jade at 4 h post-lesion only labelled the core of the excitotoxic lesion. Longer survival led to enhanced Fluoro-Jade staining, and to the decline of ChAT immunoreactivity reaching a maximum 24 h post-surgery. Significant loss of p75 low-affinity neurotrophin receptor immunoreactivity and of cortical AChE-positive projections only became apparent 48 h post-lesion. Carbocyanine 3-192IgG labelling in the ipsilateral basal forebrain exceeded that of the contralateral hemisphere at all time points investigated and progressively declined in the damaged magnocellular nucleus basalis up to 48 h after NMDA infusion. The present study indicates that excitotoxic lesion-induced alteration of cholinergic neuronal markers is a rapid and gradual process reaching its maximum 24 h post-surgery. Furthermore, in vivo labelling of cholinergic neurons may be applied to indicate neuronal survival under pathological conditions, and enable to follow their degeneration process under a variety of experimental conditions.

Oral post-lesion administration of 5-HT(1A) receptor agonist repinotan hydrochloride (BAY x 3702) attenuates NMDA-induced delayed neuronal death in rat magnocellular nucleus basalis.

Recent evidence indicates that stimulation of postsynaptic 5-HT(1A) receptors abates excitotoxic neuronal death. Here we investigated whether oral post-lesion administration of the 5-HT(1A) receptor agonist (-)-(R)-2-[4-[[(3,4-dihydro-2H-1-benzopyran-2-yl)methyl]amino]butyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide monohydrochloride (Repinotan HCl) attenuates N-methyl-D-aspartate (NMDA) excitotoxicity (60 nmol/microl) in the rat magnocellular nucleus basalis. Repinotan HCl (1 mg/kg) was administered from day 1, 2, 3, or 6 post-surgery twice daily for five consecutive days. This delayed drug administration protocol was employed to investigate the initiation period during which 5-HT(1A) receptor agonists may significantly influence ongoing neurodegeneration processes. 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 1 mg/kg) served as reference compound. Twenty-four hours after drug delivery a small open-field test, while on day 14 post-surgery a passive avoidance test was performed. Effects of Repinotan HCl treatment on the survival of cholinergic magnocellular nucleus basalis neurons and their cortical projections were determined by quantitative acetylcholinesterase (AChE) and choline-acetyltransferase (ChAT) histochemistry. Moreover, AChE and ChAT activities were biochemically measured both in the cerebral cortex and in the magnocellular nucleus basalis. Repinotan HCl treatment markedly increased spontaneous activities in the small open-field at any time-point investigated. Improved memory performance was only demonstrated when Repinotan HCl was administered from day 1 post-lesion on wards. Repinotan HCl treatment from day 2 and 3 post-lesion on markedly attenuated both histochemical and neurochemical characteristics of NMDA excitotoxicity on cholinergic magnocellular nucleus basalis neurons and on their cortical projections. Whereas the neuroprotective profile of Repinotan HCl was superior to that of 8-OH-DPAT, oral administration of both 5-HT(1A) receptor agonists yielded largely equivalent behavioral recovery after NMDA infusion in the magnocellular nucleus basalis. In conclusion, the present data indicate the potent neuroprotective action of the 5-HT(1A) receptor agonist Repinotan HCl with a peak efficacy of delayed (2-3 day) post-lesion drug treatment in vivo. Post-lesion treatment with 5-HT(1A) receptor agonists may therefore be of significance in the intervention of neuronal damage associated with acute excitotoxic conditions.

Beta-amyloid(1-42)-induced cholinergic lesions in rat nucleus basalis bidirectionally modulate serotonergic innervation of the basal forebrain and cerebral cortex.

Ample experimental evidence suggests that beta-amyloid (A beta), when injected into the rat magnocellular nucleus basalis (MBN), impels excitotoxic injury of cholinergic projection neurons. Whereas learning and memory dysfunction is a hallmark of A beta-induced cholinergic deficits, anxiety, or hypoactivity under novel conditions cannot be attributed to the loss of cholinergic MBN neurons. As mood-related behavioral parameters are primarily influenced by the central serotonergic system, in the present study we investigated whether A beta(1-42) toxicity in the rat MBN leads to an altered serotonergic innervation pattern in the rat basal forebrain and cerebral cortex 7 days postsurgery. A beta infusion into the MBN elicited significant anxiety in the elevated plus maze. A beta toxicity on cholinergic MBN neurons, expressed as the loss of acetylcholinesterase-positive cortical projections, was accompanied by sprouting of serotonergic projection fibers in the MBN. In contrast, the loss of serotonin-positive fiber projections, decreased concentrations of both serotonin and 5-hydroxyindoleacetic acid, and decline of cortical 5-HT(1A) receptor binding sites indicated reduced serotonergic activity in the somatosensory cortex. In conclusion, the A beta-induced primary cholinergic deficit in the MBN and subsequent cortical cholinergic denervation bidirectionally modulate serotonergic parameters in the rat basal forebrain and cerebral cortex. We assume that enhanced serotonin immunoreactivity in the damaged MBN indicates intrinsic processes facilitating neuronal recovery and cellular repair mechanisms, while diminished cortical serotonergic activity correlates with the loss of the subcortical cholinergic input, thereby maintaining the balance of neurotransmitter concentrations in the cerebral cortex.