790 research outputs found
Post-traumatic stress disorder: the neurobiological impact of psychological trauma
The classic fight-or-flight response to perceived threat is a reflexive nervous phenomenon thai has obvious survival advantages in evolutionary terms. However, the systems that organize the constellation of reflexive survival behaviors following exposure to perceived threat can under some circumstances become dysregulated in the process. Chronic dysregulation of these systems can lead to functional impairment in certain individuals who become “psychologically traumatized” and suffer from post-traumatic stress disorder (PTSD), A body of data accumulated over several decades has demonstrated neurobiological abnormalities in PTSD patients. Some of these findings offer insight into the pathophysiology of PTSD as well as the biological vulnerability of certain populations to develop PTSD, Several pathological features found in PTSD patients overlap with features found in patients with traumatic brain injury paralleling the shared signs and symptoms of these clinical syndromes
Future prospects in depression research
Major depression is a common, disabling, and often difficult-to-treat illness. Decades of research into the neurobiology and treatment of depression have greatly advanced our ability to manage this disorder. However, a number of challenges remain. A substantial number of depressed patients do not achieve full remission despite optimized treatment. For patients who do achieve resolution of symptoms, depression remains a highly recurrent illness, and repeated episodes are common. Finally, little is known about how depression might be prevented, especially in individuals at increased risk. In the face of these challenges, a number of exciting research efforts are currently under way and promise to greatly expand our knowledge of the etiology, pathophysiology, and treatment of depression. This review highlights these future prospects for depression research with a specific focus on lines of investigation likely to generate novel, more effective treatment options
Failure to Recover from Proactive Semantic Interference Differentiates Amnestic Mild Cognitive Impairment and PreMCI from Normal Aging after Adjusting for Initial Learning Ability
Background: There is increasing evidence that the failure to recover from proactive semantic interference (frPSI) may be an early cognitive marker of preclinical Alzheimer’s disease (AD). However, it is unclear whether frPSI effects reflect deficiencies in an individual’s initial learning capacity versus the actual inability to learn new semantically related targets. Objective: The current study was designed to adjust for learning capacity and then to examine the extent to which frPSI, proactive semantic interference (PSI) and retroactive semantic interference (RSI) effects could differentiate between older adults who were cognitively normal (CN), and those diagnosed with either Pre-Mild Cognitive Impairment (PreMCI) or amnestic MCI (aMCI). Methods: We employed the LASSI-L cognitive stress test to examine frPSI, PSI and RSI effects while simultaneously controlling for the participant’s initial learning capacity among 50 CN, 35 aMCI, and 16 PreMCI participants who received an extensive diagnostic work-up. Results: aMCI and PreMCI participants showed greater frPSI deficits (50% and 43.8% respectively) compared to only 14% of CNparticipants. PSI effects were observed for aMCI but not PreMCI participants relative to their CN counterparts. RSI failed to differentiate between any of the study groups. Conclusion: By using participants as their own controls and adjusting for overall learning and memory, it is clear that frPSI deficits occur with much greater frequency in individuals at higher risk for Alzheimer’s disease (AD), and likely reflect a failure of brain compensatory mechanisms.Fil: Curiel, Rosie E.. University of Miami; Estados UnidosFil: Crocco, Elizabeth A.. University of Miami; Estados UnidosFil: Raffo, Arlene. University of Miami; Estados UnidosFil: Guinjoan, Salvador Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Nemeroff, Charles B.. University of Miami; Estados UnidosFil: Penate, Ailyn. Mount Sinai Medical Center; Estados Unidos. University of Miami; Estados UnidosFil: Piña, Daema. University of Miami; Estados UnidosFil: Loewenstein, David A.. Mount Sinai Medical Center; Estados Unidos. University of Miami; Estados Unido
Effect of Childhood Trauma on Adult Depression and Neuroendocrine Function: Sex-Specific Moderation by CRH Receptor 1 Gene
Variations of the corticotropin-releasing hormone receptor 1 (CRHR1) gene appear to moderate the development of depression after childhood trauma. Depression more frequently affects women than men. We examined sex differences in the effects of the CRHR1 gene on the relationship between childhood trauma and adult depression. We recruited 1,063 subjects from the waiting rooms of a public urban hospital. Childhood trauma exposure and symptoms of depression were assessed using dimensional rating scales. Subjects were genotyped for rs110402 within the CRHR1 gene. An independent sample of 78 subjects underwent clinical assessment, genotyping, and a dexamethasone/CRH test. The age range at recruitment was 18–77 years and 18–45, for the two studies respectively. In the hospital sample, the protective effect of the rs110402 A-allele against developing depression after childhood trauma was observed in men (N = 424), but not in women (N = 635). In the second sample, the rs110402 A-allele was associated with decreased cortisol response in the dexamethasone/CRH test only in men. In A-allele carriers with childhood trauma exposure women exhibited increased cortisol response compared men; there were no sex differences in A-allele carriers without trauma exposure. This effect may, however, not be related to gender differences per se, but to differences in the type of experienced abuse between men and women. CRHR × environment interactions in the hospital sample were observed with exposure to physical, but not sexual or emotional abuse. Physical abuse was the most common type of abuse in men in this cohort, while sexual abuse was most commonly suffered by women. Our results suggest that the CRHR1 gene may only moderate the effects of specific types of childhood trauma on depression. Gender differences in environmental exposures could thus be reflected in sex-specific CRHR1 × child abuse interactions
Executive functioning in cognitively normal middle-aged offspring of late-onset Alzheimer's disease patients
Episodic memory deficits are traditionally seen as the hallmark cognitive impairment during the prodromal continuum of late-onset Alzheimer's disease (LOAD). Previous studies identified early brain alterations in regions subserving executive functions in asymptomatic, middle-aged offspring of patients with LOAD (O-LOAD), suggesting that premature episodic memory deficits could be associated to executive dysfunction in this model. We hypothesized that O-LOAD would exhibit reduced executive performance evidenced by increased errors and decreased strategy use on an episodic memory task. We assessed 32 asymptomatic middle-aged O-LOAD and 28 age-equivalent control subjects (CS) with several tests that measure executive functions and the Rey Auditory Verbal Learning Test (RAVLT) to measure memory performance. All tests were scored using both traditional and process scores (quantification of errors and strategies underlying overall performance). T-tests were used to compare performance between both groups and Spearman correlations were implemented to measure associations between variables. O-LOAD participants exhibited decreased executive performance compared to CS as it relates to initiation time (Tower of London), mental switching (Trail Making Test B), and interference effects (Stroop Word-Color condition). Traditional RAVLT measures showed a poorer performance by O-LOAD and RAVLT process scores revealed increased interference effects on this group. Positive correlations (r s ) were found between the executive measures and several RAVLT measures for O-LOAD but not for CS. In conclusion, O-LOAD participants exhibited early subtle cognitive changes in executive processing. Observed memory difficulties may be associated in part to executive deficits suggesting an interplay between memory and executive functions. Process score impairments were observed earlier than clinical decline on neuropsychological scores in this at-risk cohort and might be useful cognitive markers of preclinical LOAD.Fil: Abulafia, Carolina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Fiorentini, Leticia. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Loewenstein, David A.. University of Miami; Estados UnidosFil: Curiel Cid, Rosie. University of Miami; Estados UnidosFil: Sevlever, Gustavo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Nemeroff, Charles B.. University of Texas at Austin; Estados UnidosFil: Villarreal, Mirta Fabiana. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Vigo, Daniel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Guinjoan, Salvador Martín. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; Argentin
Asymmetrical Contribution of Brain Structures to Treatment-Resistant Depression As Illustrated by Effects of Right Subgenual Cingulum Stimulation
Major depressive disorder is one of the most common psychiatric disorders, with a worldwide lifetime prevalence rate of 10%-20% in women and a slightly lower rate in men. While many patients are successfully treated using established therapeutic strategies, a significant percentage of patients fail to respond. This report describes the successful recovery of a previously treatment-resistant patient following right unilateral deep brain stimulation of Brodmann´s area 25. Current therapeutic approaches to treatment-resistant patients are reviewed in the context of this case with an emphasis on the role of the right and left hemispheres in mediating disease pathogenesis and clinical recovery.Fil: Guinjoan, Salvador Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Mayberg, Helen S.. University Of Emory; Estados UnidosFil: Costanzo, Elsa Y.. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Fahrer, Rodolfo D.. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Tenca, Eduardo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Antico, Julio. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Cerquetti, Daniel. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Smyth, Elisa. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Leiguarda, Ramón Carlos. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Nemeroff, Charles B.. University of Miami; Estados Unido
Early life programming and neurodevelopmental disorders.
For more than a century, clinical investigators have focused on early life as a source of adult psychopathology. Early theories about psychic conflict and toxic parenting have been replaced by more recent formulations of complex interactions of genes and environment. Although the hypothesized mechanisms have evolved, a central notion remains: early life is a period of unique sensitivity during which experience confers enduring effects. The mechanisms for these effects remain almost as much a mystery today as they were a century ago. Recent studies suggest that maternal diet can program offspring growth and metabolic pathways, altering lifelong susceptibility to diabetes and obesity. If maternal psychosocial experience has similar programming effects on the developing offspring, one might expect a comparable contribution to neurodevelopmental disorders, including affective disorders, schizophrenia, autism, and eating disorders. Due to their early onset, prevalence, and chronicity, some of these disorders, such as depression and schizophrenia, are among the highest causes of disability worldwide according to the World Health Organization 2002 report. Consideration of the early life programming and transcriptional regulation in adult exposures supports a critical need to understand epigenetic mechanisms as a critical determinant in disease predisposition. Incorporating the latest insight gained from clinical and epidemiological studies with potential epigenetic mechanisms from basic research, the following review summarizes findings from a workshop on Early Life Programming and Neurodevelopmental Disorders held at the University of Pennsylvania in 2009
White matter fiber density abnormalities in cognitively normal adults at risk for late-onset Alzheimer's disease
Tau accumulation affecting white matter tracts is an early neuropathological feature of late-onset Alzheimer's disease (LOAD). There is a need to ascertain methods for the detection of early LOAD features to help with disease prevention efforts. The microstructure of these tracts and anatomical brain connectivity can be assessed by analyzing diffusion MRI (dMRI) data. Considering that family history increases the risk of developing LOAD, we explored the microstructure of white matter through dMRI in 23 cognitively normal adults who are offspring of patients with Late-Onset Alzheimer's Disease (O-LOAD) and 22 control subjects (CS) without family history of AD. We also evaluated the relation of white matter microstructure metrics with cortical thickness, volumetry, in vivo amyloid deposition (with the help of PiB positron emission tomography -PiB-PET) and regional brain metabolism (as FDG-PET) measures. Finally we studied the association between cognitive performance and white matter microstructure metrics. O-LOAD exhibited lower fiber density and fractional anisotropy in the posterior portion of the corpus callosum and right fornix when compared to CS. Among O-LOAD, reduced fiber density was associated with lower amyloid deposition in the right hippocampus, and greater cortical thickness in the left precuneus, while higher mean diffusivity was related with greater cortical thickness of the right superior temporal gyrus. Additionally, compromised white matter microstructure was associated with poorer semantic fluency. In conclusion, white matter microstructure metrics may reveal early differences in O-LOAD by virtue of parental history of the disorder, when compared to CS without a family history of LOAD. We demonstrate that these differences are associated with lower fiber density in the posterior portion of the corpus callosum and the right fornix.Fil: Sanchez, Stella Maris. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Duarte Abritta, Barbara Micaela. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Abulafia, Carolina Andrea. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: de Pino, Gabriela. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Bocaccio, Hernan. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Castro, Mariana Nair. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Salud Mental; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Sevlever, Gustavo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Fonzo, Greg A.. University of Texas at Austin; Estados UnidosFil: Nemeroff, Charles B.. University of Texas at Austin; Estados UnidosFil: Gustafson, Deborah. State University of New York; Estados Unidos. University of Skövde; SueciaFil: Guinjoan, Salvador Martín. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Neurofisiología; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Salud Mental; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Villarreal, Mirta Fabiana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; Argentin
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