Neuroimaging Research (neuroimaging + research)

Distribution by Scientific Domains

Selected Abstracts

A survey of neuroimaging research in European neurological departments

K. Herholz
In the international neurological literature, neuroimaging research plays an important role. Neuroimaging techniques are also of steadily increasing importance for clinical diagnosis and treatment monitoring. Therefore, neuroimaging research activities were surveyed by a questionnaire, which was completed by 100 neurological centres across Europe. It showed that most groups use magnetic resonance imaging (MRI), fMRI, computerized tomography (CT) and single photon emission computerized tomography (SPECT). Positron emission tomography (PET) and ultrasound are also employed by nearly half of the centres. Neuroimaging research involves co-operation amongst typically five to 10 disciplines. Cerebrovascular disease, dementia, cognitive disorders, epilepsy, movement disorders, brain tumours and multiple sclerosis are frequently being studied. Many groups rely on small budgets, have few full-time scientists and limited access to expensive resources. There is little exchange of scientists amongst laboratories. It was felt that funding and co-operation needed improvement in order to maintain a high standard in neuroimaging research. [source]

Corpus callosum and posterior fossa development in monozygotic females: a morphometric MRI study of Turner syndrome

Susannah L Fryer BA
Previous neuroimaging research in Turner syndrome (TS) has indicated parietal lobe anomalies, while anomalies in other brain loci have been less well-substantiated. This study focused on potential cerebellar abnormalities and possible disruptions of interhemispheric (parietal) callosal connections in individuals with TS. Twenty-seven female children and adolescents with TS (mean age 13 years, SD 4 years 2 months) and 27 age-matched female control individuals (mean age 13 years 2 months, SD 4 years 1 month) underwent MRI. Age range of all participants was 7 to 20 years. Morphometric analyses of midline brain structures were conducted using standardized, reliable methods. When compared with control participants, females with TS showed reduced areas of the genu of the corpus callosum, the pons, and vermis lobules VI,VII, and an increased area of the fourth ventricle. No group difference in intracranial area measurements was observed. The reduced area of the genu in TS may reflect compromised connectivity between inferior parietal regions. Further, cerebellar vermis hypoplasia associated with TS agrees with literature that suggests the posterior fossa as a region prone to structural alterations in the face of early developmental insult. [source]

Differential contributions of the parahippocampal place area and the anterior hippocampus to human memory for scenes

HIPPOCAMPUS, Issue 6 2002
Stefan Köhler
Abstract Past neuroimaging research has identified a parahippocampal place area (PPA) in the posterior medial temporal lobe (MTL), which responds preferentially to visual scenes and plays a role in episodic memory for this class of stimuli. In the present positron emission tomography study, we examined to what extent the functional characteristics of the PPA resemble those of other, more anterior MTL regions across various learning and recognition-memory tasks. We also determined whether the involvement of the PPA in recognition of previously studied scenes is specific to a particular type of scene information. We found that, like the PPA, anterior hippocampal regions showed a novelty response (higher activation for novel than repeated scenes) and a stimulus-related response (higher activation for scenes than objects) during learning, indicating that MTL structures other than the PPA contribute to the encoding of novel stimulus relationships in scenes. However, these anterior hippocampal regions showed no involvement during recognition of either spatial or nonspatial information contained in scenes. The PPA, by contrast, was consistently involved in recognition of all types of scene details, presumably through interactions with co-activated parietal and occipitotemporal cortices. We suggest that MTL contributions from the PPA are sufficient to support recognition of scenes when the task can be based on a perceptually based familiarity process. Hippocampus 2002;12:718,723. © 2002 Wiley-Liss, Inc. [source]

Recent advances in the neurobiology of anxiety disorders: Implications for novel therapeutics,

Sanjay J. Mathew
Abstract Anxiety disorders are a highly prevalent and disabling class of psychiatric disorders. This review focuses on new directions in neurobiological research and implications for the development of novel psychopharmacological treatments. Neuroanatomical and neuroimaging research in anxiety disorders has centered on the role of the amygdala, reciprocal connections between the amygdala and the prefrontal cortex, and, most recently, alterations in interoceptive processing by the anterior insula. Anxiety disorders are characterized by alterations in a diverse range of neurochemical systems, suggesting ample novel targets for drug therapies. Corticotropin-releasing factor (CRF) concentrations are elevated in a subset of anxiety disorders, which suggests the potential utility of CRF receptor antagonists. Pharmacological blockade of the memory-enhancing effects of stress hormones such as glucocorticoids and noradrenaline holds promise as a preventative approach for trauma-related anxiety. The glutamatergic system has been largely overlooked as a potential pharmacological target, although convergent preclinical, neuroimaging, and early clinical findings suggest that glutamate receptor antagonists may have potent anxiolytic effects. Glutamatergic receptor agonists (e.g., D -cycloserine) also have an emerging role in the treatment of anxiety as facilitators of fear extinction during concurrent behavioral interventions. The neuropeptides substance P, neuropeptide Y, oxytocin, orexin, and galanin are each implicated in anxiety pathways, and neuropeptide analogs or antagonists show early promise as anxiolytics in preclinical and/or clinical research. Each of these active areas of research holds promise for expanding and improving evidence-based treatment options for individuals suffering with clinical anxiety. © 2008 Wiley-Liss, Inc. [source]


BIOETHICS, Issue 6 2009
ABSTRACT According to many researchers, it is inevitable and obvious that psychiatric illnesses are biological in nature, and that this is the rationale behind the numerous neuroimaging studies of individuals diagnosed with mental disorders. Scholars looking at the history of psychiatry have pointed out that in the past, the origins and motivations behind the search for biological causes, correlates, and cures for mental disorders are thoroughly social and historically rooted, particularly when the diagnostic category in question is the subject of controversy within psychiatry. This is obscured by neuroimaging studies that drive researchers to proclaim ,revolutions' in psychiatry, namely in the DSM. Providing neuroimaging evidence to support the contention that a condition is ,real' is likely to be extremely influential, as has been extensively discussed in the neuroethics literature. This type of evidence will also reinforce the pre-existing beliefs of those researchers or clinicians who are already expecting a biological description. The uncritical credence given to neuroimaging research is an ethical issue, not in its potential for contributing to misdiagnosis per se but because of the motivations that often drive this research. My claim is that this research should proceed with an awareness of presumptions and motivations underlying the field as a whole, in addition to an explicit focus on the past and potential future consequences of classification and diagnosis on the groups of individuals under study. [source]