The behavioral and immunological impact of maternal separation: a matter of timing

Maternal separation (MS), an early life stressful event, has been demonstrated to trigger neuropsychiatric disorders later in life, in particular depression. Experiments using rodents subjected to MS protocols have been very informative for the establishment of this association. However, the mechanism by which MS leads to neuropsychiatric disorders is far from being understood. This is probably associated with the multifactorial nature of depression but also with the fact that different research MS protocols have been used (that vary on temporal windows and time of exposure to MS). In the present study, MS was induced in rats in two developmental periods: for 6h per day for 14 days between postnatal days 2-15 (MS2-15) and 7-20 (MS7-20). These two periods were defined to differ essentially on the almost complete (MS2-15) or partial (MS7-20) overlap with the stress hypo-responsive period. Behavioral, immunological, and endocrine parameters, frequently associated with depressive-like behavior, were analyzed in adulthood. Irrespectively from the temporal window, both MS exposure periods led to increased sera corticosterone levels. However, only MS2-15 animals displayed depressive and anxious-like behaviors. Moreover, MS2-15 was also the only group presenting alterations in the immune system, displaying decreased percentage of CD8(+) T cells, increased spleen T cell CD4/CD8 ratio, and thymocytes with increased resistance to dexamethasone-induced cell death. A linear regression model performed to predict depressive-like behavior showed that both corticosterone levels and T cell CD4/CD8 ratio explained 37% of the variance observed in depressive-like behavior. Overall, these findings highlight the existence of "critical periods" for early life stressful events to exert programing effects on both central and peripheral systems, which are of relevance for distinct patterns of susceptibility to emotional disorders later in life.We acknowledge the Portuguese Foundation for Science and Technology (FCT) for providing a fellowship to S. Roque (SFRH/BPD/72710/2010). This work was also supported by FCT grants (co-financed by COMPETE funds) PTDC/SAU-NEU/105180/2008 and PTDC/PSI-PCO/116612/2010 and co-financed by the Portuguese North Regional Operational Program (ON.2 - O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER)

La sensibilisation comportementale à l'amphétamine (implication de la transmission b-adrénergique et des afférences à l'aire tegmentale ventrale)

L'amphétamine induit chez le rat une sensibilisation comportementale qui se traduit par une augmentation de la réponse motrice à ce psychostimulant. Les neuroadaptations sous-tendant ce phénomène, qui seraient aussi impliquées dans le comportement compulsif de recherche de drogue, ont surtout été associées au système dopaminergique issu de l'aire tegmentale ventrale (ATV). Cependant, d'autres systèmes de neurotransmetteurs contribueraient également à la sensibilisation. Dans ce travail, nous avons montré que la transmission -adrénergique centrale, en particulier dans le noyau du lit de la strie terminale, est nécessaire à l'activation neuronale précoce et l'initiation de la sensibilisation comportementale induites par l'amphétamine. Nous avons de plus identifié les neurones projetant à l'ATV et activés par cette drogue. Ce travail a ainsi permis de mettre en évidence de nouveaux circuits et substrats neuronaux potentiellement engagés dans les effets à long terme des psychostimulantsLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Enhanced tail pinch-induced activation of catecholamine metabolism in the pericerulean area of RU 24722-treated rats

Our study was devoted to determine in freely moving rats whether the increase in tissue concentration of tyrosine hydroxylase (TH) elicited by a single administration of RU 24722 could modify the catecholaminergic reactivity of neuronal processes present in the rostrolateral part of the pericerulean area (r-lPCA) in response to tail pinch. Catecholaminergic activity was monitored by measuring in vivo the concentration of dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) using microdialysis coupled to HPLC detection. In this study, the microdialysis probe was implanted at a sufficient distance from the lateral border of rostral nucleus locus ceruleus (LC) to avoid a large contribution of the noradrenergic cell bodies in the measurements performed. We first evidenced that DOPAC measured in the r-lPCA indicated the functional state of catecholaminergic metabolism in neuronal processes (dendrites and fibers) laying in this region. We also showed that the enhancement of TH protein concentration in the r-lPCA following RU 24722 treatment supported an increased in vivo catecholaminergic metabolism in this region. Furthermore, catecholaminergic metabolism response to tail pinch was potentiated in animals with greater TH tissue concentration. Thus, our study reveals that the modulation of both TH concentration and catecholaminergic metabolism in the r-lPCA may be critical in the functioning of cells and neuronal elements present in this region, notably in adaptive responses to noxious stimuli

Epilepsy and Psychiatric Comorbidities: New Approaches and Perspectives

Psychiatry and neurology are specialties learned separately, but often the semiology and the pathophysiology of the different cases are linked. Patients often need an integrative approach in order to have an appropriate answer to their problems. In this chapter we will discuss the psychiatric comorbidities of epilepsy, such as depression, psychosis, stress, and anxiety disorders. Depression is the most common psychiatric comorbidity of epilepsy, significantly affecting the quality of life of patients. Anxiety disorders occupy a second place, often generating severe problems. They are usually underestimated at the clinical level, despite the abundant scientific evidence that supports the search and treatment of them in this group of patients. The problem of psychotic disorders in epilepsy is often controversial. There are few studies on this subject, and the psychopathological mechanisms behind them remain largely unknown. The problem of diagnoses and management of psychogenic nonepileptic seizures will also be briefly reviewed. They usually represent 20% of the patients referred to specialized centers of epilepsy, after having spent between 5 and 10 years through the health system. They are a frequent entity but often confused and mistreated, generating unnecessary expenses and waste of time. Finally, we will summarize how the management of stress and emotions in general has a direct impact on the quality of life of these patients.Fil: Gargiulo, Ángel José Martín. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: Scévola, Maria Laura. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: Sarudiansky, Mercedes. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Universidad de Buenos Aires. Facultad de Psicología; ArgentinaFil: Kochen, Sara Silvia. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: D`alessio, Luciana. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentin