Naguib Mechawar

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A method for determining the length of acetylcholine (ACh) axons and number of ACh axon varicosities (terminals) in brain sections immunostained for choline acetyltransferase (ChAT) was used to estimate the areal and laminar densities of this innervation in the frontal (motor), parietal (somatosensory), and occipital (visual) cortex of adult rat. The number(More)
Suicide and related behaviors are complex phenomena associated with different risk factors. Although most individuals who display suicidal behavior do not have a history of early-life adversity, a significant minority does. Recent animal and human data have suggested that early-life adversity leads to epigenetic regulation of genes involved in(More)
In this review, we examine the history of the neurobiology of suicide, as well as the genetics, molecular and neurochemical findings in suicide research. Our analysis begins with a summary of family, twin, and adoption studies, which provide support for the investigation of genetic variation in suicide risk. This leads to an overview of neurochemical(More)
CONTEXT Our genome adapts to environmental influences, in part through epigenetic mechanisms, including DNA methylation. Variations in the quality of the early environment are associated with alterations in DNA methylation in rodents, and recent data suggest similar processes in humans in response to early-life adversity. OBJECTIVE To determine(More)
Microglia can adopt different morphologies, ranging from a highly ramified to an amoeboid-like phenotype. Although morphological properties of microglia have been described in rodents, little is known about their fine features in humans. The aim of this study was to characterize the morphometric properties of human microglia in gray and white matter of(More)
BACKGROUND Childhood abuse alters hypothalamic-pituitary-adrenal (HPA) function and increases the risk of suicide. Hippocampal glucocorticoid receptor (GR) activation regulates HPA activity, and human GR expression (hGR) is reduced in the hippocampus of suicide completers with a history of childhood abuse compared with controls. The abuse-related decrease(More)
BACKGROUND Most studies investigating the neurobiology of depression and suicide have focused on the serotonergic system. While it seems clear that serotonergic alterations play a role in the pathogenesis of these major public health problems, dysfunction in additional neurotransmitter systems and other molecular alterations may also be implicated.(More)
Schizophrenia is a severe neuropsychiatric disorder that is hypothesized to result from disturbances in early brain development. There is mounting evidence to support a role for developmentally regulated epigenetic variation in the molecular etiology of the disorder. Here, we describe a systematic study of schizophrenia-associated methylomic variation in(More)
The mitochondrial flavoprotein apoptosis-inducing factor (AIF) is the main mediator of caspase-independent apoptosis-like programmed cell death. Upon pathological permeabilization of the outer mitochondrial membrane, AIF is translocated to the nucleus, where it participates in chromatin condensation and is associated to large-scale DNA fragmentation. Heavy(More)