Epigenetics is the study of the variations of genetic expression that occur not because of differences in DNA structure, but because of chromatin alternations that modulate DNA transcription. The mechanisms of epigenetics are thus the link between genome and phenotype. This article will explore the best known epigenetic mechanisms, namely DNA methylation and histone modifications and how they may lead to the emergence of depression and schizophrenia.
View Article and Find Full Text PDFAntipsychotics play a key role in biologic therapy of schizophrenia. Following the first-generation neuroleptics, associated with many extrapyramidal side effects (severe dystonias, parkinsonian syndrome, akatisia and late dyskinesia) altering patients' compliance to the treatment, one can now find a new generation of molecules considered as atypical antipsychotics because they rarely cause neurological complications. This propriety provides a better compliance, along with a clear decrease of late dyskinesia risk but the effectiveness compared to ordinary molecules is still questioned.
View Article and Find Full Text PDFThe case report describes a 45-year old man presenting of the behavioral problems and an aphasia of Wernicke, hospitalized under constraint. The urinary screening in the search of psychotropic substances is positive for the cannabis and the amphetamines. The neurological localization is confirmed by cerebral CT-scan.
View Article and Find Full Text PDFFor some neurobiologists, present biological descriptions of the brain may integrate the theoretical frame initiated by Freud. The recent acquisitions of neurobiology prove a plasticity of the neural network anabling the inscription of the experiment. The neuroplasticity constitutes the cornerstone of the reconciliation between the psychoanalysis and neurosciences.
View Article and Find Full Text PDFThis paper is a review of the principal, currently proposed, biological models of schizophrenia. The convergence of recent neurobiological studies indicates that schizophrenia may be a neurodevelopmental and progressive disorder with multiple biochemical abnormalities involving dopamine, serotonin, glutamate and gamma-aminobutyric acidergic systems. In post-mortem tissue, structural abnormalities and alterations in synaptic connectivity have been observed in the intracortical circuitry of the prefrontal dorsal cortex.
View Article and Find Full Text PDFIntroduction: Many authors have described these last years the difficulty to establish a differential diagnosis between schizophrenia and frontotemporal dementia. However treatment and prognosis of these two separate diseases are not the same. Schizophrenia is a chronic syndrome with an early onset during teenage or young adulthood period and the major features consist of delirious ideas, hallucinations and psychic dissociation.
View Article and Find Full Text PDFJ Neurol Neurosurg Psychiatry
July 2003
The Department of Psychiatry was first opened in April 1978. It is one of the largest sector of the hospital and contains 90 beds including a sleep laboratory and an adolescent unit. The clinical activities are broad and multidisciplinary, including novel psychopharmacological and psychotherapeutic and psychosocial approaches.
View Article and Find Full Text PDFInt J Eat Disord
January 1999
Objective: As anorectic and bulimic patients present similar clinical and neurobiological symptoms, the purpose of this study was to compare brain glucose metabolism at rest in these patients.
Methods: Positron emission tomography with (18-F)-fluorodeoxyglucose was used to evaluate cerebral glucose metabolism (CMRglu) in 10 normal-weight bulimic women, in 10 underweight anorectic patients, and in 10 age- and sex-matched healthy volunteers.
Results: Absolute global cortical glucose activity was significantly lower in anorectic patients compared with bulimic and control subjects.
Background: Serotonin receptors may play an important role in the pathophysiology of affective disorders. We studied type-2 serotonin (5-HT2) receptors in the brain of patients with major depression.
Method: Using positron emission tomography (PET) and the selective radioligand [18F]altanserin, we investigated 5-HT2 receptor distribution in eight drug-free unipolar depressed patients and 22 healthy subjects.
As low-weight anorectic patients presented a global as well as a regional absolute hypometabolism of glucose, we investigated a population of ten age- and sex-matched low-weight depressed patients without anorexia nervosa to evaluate the impact of weight loss on cerebral glucose metabolism evaluated by positron emission tomography and [18F]-fluorodeoxyglucose. Ten age- and sex-matched healthy volunteers were used as controls. Absolute global and regional glucose activity was significantly lower in anorectic and low weight depressed patients than in control subjects.
View Article and Find Full Text PDFRelationships between eating and affective disorders remain complex and unclear. Brain glucose metabolism of anorectic patients has been demonstrated to be reduced both globally and regionally, with a particular relative hypometabolism in the parietal cortex. To explore the possible influence of weight loss or depressive symptomatology on brain metabolism, we studied age- and sex-matched low-weight anorectic and depressed patients, normal-weight depressed patients, and healthy volunteers.
View Article and Find Full Text PDFTo further validate its use in positron emission tomography (PET), we studied the binding of [18F]altanserin, a specific 5HT2 radioligand, in the rat brain using in vivo autoradiography. Distribution of [18F]altanserin binding was comparable to the in vitro mapping of 5HT2 receptors reported in the literature. Selective displacers were used to test the reversibility and the selectivity of this radioligand.
View Article and Find Full Text PDFObjective: A cerebral function lateralization has been described in bulimic patients in positron emission tomography (PET) studies realized during a specific cognitive task. The purpose of this study was to evaluate, at rest, brain glucose metabolism in patients with bulimia nervosa.
Method: PET with (18-F)-fluorodeoxyglucose was used to evaluate cerebral glucose metabolism in 11 normal-weight bulimic girls compared to 11 age- and sex-matched healthy volunteers.
Using positron emission tomography and (18-F)-fluorodeoxyglucose, we studied cerebral glucose metabolism in 10 anorectic girls within their underweight state and after weight gain. Ten age- and sex-matched healthy volunteers were used as controls. Both groups were scanned during rest, eyes closed and with low ambient noise.
View Article and Find Full Text PDFEur Neuropsychopharmacol
May 1996
To investigate metabolic relationships between different brain regions in schizophrenia, we measured regional brain metabolism using positron emission tomography (PET) and [18F]fluorodeoxyglucose (FDG) in 15 unmedicated schizophrenic patients and 15 healthy subjects. We analyzed correlations between glucose metabolism data of multiple brain regions using factorial analysis and correlation coefficient comparisons. Absolute regional intercorrelations in schizophrenic brains were found to be significantly stronger than in controls, in relationship to the greater variability of metabolic rates in schizophrenic patients.
View Article and Find Full Text PDFPositron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (FDG) is frequently used to study the metabolic correlates of movement and mental disorders. These studies generally focus on changes in the frontal cortex and the basal ganglia. The reproducibility of glucose metabolism estimates in these structures was tested in 13 normal subjects studied at rest using a standard and simple protocol.
View Article and Find Full Text PDFPsychiatry Res
September 1995
Positron emission tomography with [18F]-fluoro-2-deoxy-D-glucose as tracer was used to investigate frontal glucose metabolism in 15 unmedicated schizophrenic patients and 15 healthy subjects under resting conditions. Although no difference in absolute frontal cerebral metabolic rates of glucose (CMRglu) were found between schizophrenic patients and control subjects, relative measures significantly differentiated the two groups. Whole frontal metabolism and frontocaudate ratio were significantly decreased in both hemispheres in the patients.
View Article and Find Full Text PDFActa Psychiatr Belg
January 1996
Cerebral frontal glucose metabolism was investigated in 12 unipolar depressed patients and compared to these of 12 healthy volunteers using Positron Emission Tomography (PET) and (F18) fluorodeoxyglucose. The PET investigation was made in a quiet room with a dimly light and each subject remained in a resting state with closed eyes. Results show a decreased in a frontal superobasal calculated ratio in depressed patients compared to control subjects for left and for right values.
View Article and Find Full Text PDFJ Neurol Neurosurg Psychiatry
April 1995
Brain glucose metabolism was investigated with PET and [18F]fluorodeoxyglucose, before and after a bifrontal stereotactic leukotomy in a 37 year old woman with refractory obsessive-compulsive disorder. A bilateral decrease in glucose metabolism was found in the orbital frontal cortex after psychosurgery. Glucose metabolism was decreased to a lesser degree in Brodmann's area 25, in the thalamus, and in the caudate nucleus.
View Article and Find Full Text PDFBiol Psychiatry
February 1995
Cerebral glucose metabolism was studied in 20 underweight anorectic girls and in 10 age- and sex-matched healthy volunteers using positron emission tomography with (18-F)-fluorodeoxy-glucose. Both groups were scanned during rest, with eye closed and with low ambient noise. Compared to controls, the underweight anorectic group showed a global hypometabolism (p = .
View Article and Find Full Text PDFBorderline personality disorder does not have a first choice pharmacological treatment. We studied 20 borderline inpatients in a double-blind parallel placebo-controlled trial with carbamazepine for a mean of 30.9 days.
View Article and Find Full Text PDFThe pathophysiology of borderline personality disorder (BPD) is obscure. Underlying organic factors such as epilepsy are suspected because clinical characteristics of the syndrome are similar to some manifestations of patients with complex partial seizures (CPS). Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) reveals hypometabolism in the area surrounding epileptic foci.
View Article and Find Full Text PDFThe authors investigated brain glucose utilization using positron emission tomography (PET) in 12 normal volunteers and 12 unipolar unmedicated depressed patients (six endogenous; six nonendogenous) following injection of [18F]fluoro-deoxyglucose (FDG). Compared by analyses of variance, absolute and relative regional glucose metabolic rates appeared different in depressed patients and control subjects, especially in parietal and frontal lobes. In patients with unipolar depression, metabolic rates were increased in the orbital part of the frontal lobe and decreased in a frontal dorsolateral area.
View Article and Find Full Text PDF