Search results for "Temporal cortex"
showing 10 items of 54 documents
Opposite effects of suicidality and lithium on gray matter volumes in bipolar depression
2011
Background: Mood disorders are associated with the highest increase of attempted and completed suicide. Suicidality in major depressive disorder and in schizophrenia has been associated with reduced gray matter volumes in orbitofrontal cortex. Lithium reduces the suicide risk of patients with bipolar disorder (BD) to the same levels of the general population, and can increase GM volumes. We studied the effect of a positive history of attempted suicide and ongoing lithium treatment on regional GM volumes of patients affected by bipolar depression. Methods: With a correlational design, we studied 57 currently depressed inpatients with bipolar disorder: 19 with and 38 without a positive histor…
Relationship between dopamine D2 receptor occupancy, clinical response, and drug and monoamine metabolites levels in plasma and cerebrospinal fluid. …
2009
Combining measurements of the monoamine metabolites in the cerebrospinal fluid (CSF) and neuroimaging can increase efficiency of drug discovery for treatment of brain disorders. To address this question, we examined five drug-naive patients suffering from schizophrenic disorder. Patients were assessed clinically, using the Positive and Negative Syndrome Scale (PANSS): at baseline and then at weekly intervals. Plasma and CSF levels of quetiapine and norquetiapine as well CSF 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxyindole-acetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were obtained at baseline and again after at least a 4 week medication trai…
Striatal and extrastriatal D2/D3-receptor-binding properties of ziprasidone: a positron emission tomography study with [18F]Fallypride and [11C]raclo…
2008
To elucidate the Batypicality( of ziprasidone, its striatal and extrastriatal D2/D3-receptor binding was characterized in patients with schizophrenia under steady-state conditions. These data were compared with striatal receptor occupancy values after single-dose ziprasidone ingestion in healthy controls. ( 18 F)fallypride positron emission tomography (PET) recordings were obtained in 15 patients under steady-state ziprasidone treatment at varying time points after the last dose. Binding potentials were calculated for striatal and extrastriatal regions. D2/D3-receptor occupancies were expressed relative to binding potentials in 8 unmedicated patients. In a parallel ( 11 C)raclopride-PET stu…
The striatal and extrastriatal D2/D3 receptor-binding profile of clozapine in patients with schizophrenia.
2005
Positron emission tomography (PET) studies reveal that clozapine at clinically used doses occupies less than 60% of D2/D3 dopamine receptors in human striatum. Here, the occupancy of D2/D3 dopamine receptors by clozapine in patients with schizophrenia was determined to test the hypothesis that clozapine binds preferentially to extrastriatal dopamine receptors. A total of 15 clozapine-treated inpatients with schizophrenia underwent a [18F]fallypride PET scan. Receptor occupancy was calculated as percent reduction in binding potential relative to unblocked values measured in seven normal volunteers. Mean D2/D3 receptor occupancy was statistically significantly higher in cortical (inferior tem…
Age at First Episode Modulates Diagnosis-Related Structural Brain Abnormalities in Psychosis.
2016
Brain volume and thickness abnormalities have been reported in first-episode psychosis (FEP). However, it is unclear if and how they are modulated by brain developmental stage (and, therefore, by age at FEP as a proxy). This is a multicenter cross-sectional case-control brain magnetic resonance imaging (MRI) study. Patients with FEP (n = 196), 65.3% males, with a wide age at FEP span (12-35 y), and healthy controls (HC) (n = 157), matched for age, sex, and handedness, were scanned at 6 sites. Gray matter volume and thickness measurements were generated for several brain regions using FreeSurfer software. The nonlinear relationship between age at scan (a proxy for age at FEP in patients) and…
Semantic and action tool knowledge in the brain: Identifying common and distinct networks.
2021
Most cognitive models of apraxia assume that impaired tool use results from a deficit occurring at the conceptual level, which contains dedicated information about tool use, namely, semantic and action tool knowledge. Semantic tool knowledge contains information about the prototypical use of familiar tools, such as function (e.g., a hammer and a mallet share the same purpose) and associative relations (e.g., a hammer goes with a nail). Action tool knowledge contains information about how to manipulate tools, such as hand posture and kinematics. The present review aimed to better understand the neural correlates of action and semantic tool knowledge, by focusing on activation, stimulation an…
Different World Views
2010
When we study communication systems in other animal species, we are led to the conclusion that extraterrestrial intelligent beings are likely to have systems of communication similar to the human one in at least some aspects. That is to say, communication is accomplished by means of the combination of certain information elements playing a role analogous to words, or that the system is a symbolic language (or even both things simultaneously). But in communication, it is also very important how information is transmitted (pictorially, by means of ideograms, letters, etc.), which is going to be strongly determined by the species’specific perception of the world.
[ 18 F]Fluoroethylflumazenil: a novel tracer for PET imaging of human benzodiazepine receptors
2001
5-(2'-[18F]Fluoroethyl)flumazenil ([18F]FEF) is a fluorine-18 labelled positron emission tomography (PET) tracer for central benzodiazepine receptors. Compared with the established [11C]flumazenil, it has the advantage of the longer half-life of the fluorine-18 label. After optimisation of its synthesis and determination of its in vitro receptor affinities, we performed first PET studies in humans. PET studies in seven healthy human volunteers were performed on a Siemens ECAT EXACT whole-body scanner after injection of 100-280 MBq [L8F]FEF. In two subjects, a second PET scan was conducted after pretreatment with unlabelled flumazenil (1 mg or 2.5 mg i.v., 3 min before tracer injection). A t…
Grandmother cells: much ado about nothing
2016
International audience; We do not dispute the possibility of the existence in the brain of “grandmother cells”, which are very finely tuned neurons that fire only in the presence of specific objects or categories. However, we question the causal efficacy of such neurons at the functional or behaviour level. We claim that, even though very familiar items, such as “my grandmother”, may well have associated grandmother neurons, these neurons have very little, or no impact on the actual recognition of my grandmother. A study by Thomas, Van Hulle, and Vogels [(2002). Encoding of categories by noncategory-specific neurons in the inferior temporal cortex. Journal of Cognitive Neuroscience, 13, 190…
Grey matter reduction in the occipitotemporal cortex in Spanish children with dyslexia: A voxel-based morphometry study
2020
Abstract Structural and functional neuroimaging studies have reported brain alterations in occipitotemporal, temporoparietal, and left frontal areas in dyslexic patients. These areas have been linked to reading skill impairments, due to their involvement in word recognition and processing. However, most of the patients in these studies were speakers of languages with a deep orthography. In this study, we used voxel-based morphometry (VBM) to investigate brain differences in grey matter volume associated with a transparent language in a sample of 25 native Spanish participants (13 dyslexic and 12 non-dyslexic children). Results revealed a volume reduction in the left occipitotemporal cortex …