Search results for "hippocampus"
showing 10 items of 622 documents
State dependent posterior hippocampal volume increases in patients with major depressive disorder.
2011
Abstract Background The hippocampal formation has been implicated in etiology and therapy response in major depressive disorder (MDD). However, prospective longitudinal studies investigating volumes in hippocampal subregions and their association with clinical findings are still lacking. Methods Global and regional hippocampal volumes and neuropsychological performance were assessed longitudinally in 15 young patients with unipolar early onset MDD who responded to therapy and 13 matched healthy control subjects. Results Although volumes at baseline did not differ between groups, patients with MDD showed significant posterior hippocampal volume increases during the treatment course (mean obs…
Hippocampal dose during Linac-based stereotactic radiotherapy for brain metastases: An observational study
2017
Abstract Introduction Aim of the present study is to evaluate homolateral and contralateral hippocampus (H-H, C-H, respectively) dose during Fractionated Stereotactic Radiotherapy (FSRT) or Radiosurgery (SRS) for brain metastases (BM). Materials & methods Patients with BM 3 months, were considered for SRS/FSRT (total dose 15–30 Gy, 1–5 fractions). For each BM, a Flattening Filter Free (FFF) Volumetric Modulated Arc Therapy (VMAT) plan was generated with one or two arcs. Hippocampi were not considered during optimizations phase and were contoured and evaluated retrospectively in terms of dose: the Dmedian, Dmean, D0.1cc and the V1Gy, V2Gy, V5Gy and V10Gy were analyzed. Results From April 2…
An increase of hippocampal calretinin-immunoreactive neurons correlates with early febrile seizures in temporal lobe epilepsy
1999
Numerous studies indicate that initial precipi- tating injuries (IPI) such as febrile seizures during early childhood may play a pivotal role in the pathogenesis of temporal lobe epilepsy (TLE) and Ammon's horn sclero- sis (AHS). Previous data demonstrate an increase of hori- zontally oriented neurons in molecular layers of hip- pocampal subfields, which are immunoreactive for calre- tinin (CR-ir) and resemble Cajal-Retzius-like cells. Cajal- Retzius cells are transiently expressed in the murine de- veloping hippocampus and are critically involved in neu- ronal pattern formation. Here we investigated a potential relationship between the distribution of horizontally ori- ented calretinin-imm…
Recovery of cortical volume and thickness after remission from acute anorexia nervosa
2018
Objective Reduced grey (GM) and white matter (WM) volumes and increased cerebrospinal fluid (CSF) have been frequently reported in anorexia nervosa (AN), but studies focusing on cortical thickness (CT) are scarce and findings inconsistent. We conducted the first study in AN that analyzed both parameters in the same study to gain novel and comprehensive insight. Method Voxel-based morphometry (VBM) analysis was performed on T1-weighted magnetic resonance images from 34 predominantly adult women with acute AN, 24 REC participants, and 41 healthy controls (HC). Global brain segment volumes (GM, WM, and CSF), regional GM volume, and cortical thickness measures were obtained from the same study …
Alterations in the expression of PSA-NCAM and synaptic proteins in the dorsolateral prefrontal cortex of psychiatric disorder patients.
2012
Alterations in the structure and physiology of the prefrontal cortex (PFC) have been found in different psychiatric disorders and some of them involve inhibitory networks, especially in schizophrenia and major depression. Changes in the structure of these networks may be mediated by the polysialylated neural cell adhesion molecule (PSA-NCAM), a molecule related to neuronal structural plasticity, expressed in the PFC exclusively by interneurons. Different studies have found that PSA-NCAM expression in the hippocampus and the amygdala is altered in schizophrenia, major depression and animal models of these disorders, in parallel to changes in the expression of molecules related to inhibitory …
Hedgehog signaling and primary cilia are required for the formation of adult neural stem cells.
2008
Neural stem cells that continue to produce neurons are retained in the adult hippocampal dentate gyrus. The mechanisms by which embryonic neural progenitors expand and transform into postnatal neural stem cells, an essential process for the continual production of neurons throughout life, remain unknown. We found that radial astrocytes, the postnatal progenitors in the dentate gyrus, failed to develop after embryonic ablation of ciliary genes or Smoothened (Smo), an essential component for Sonic hedgehog (Shh) signaling. Postnatal dentate neurogenesis failed in these mutant mice, and the dentate gyrus became severely hypotrophic. In contrast, expression of a constitutively active Smo (SmoM2…
A simplified framework to optimize MRI contrast preparation
2018
PURPOSE This article proposes a rigorous optimal control framework for the design of preparation schemes that optimize MRI contrast based on relaxation time differences. METHODS Compared to previous optimal contrast preparation schemes, a drastic reduction of the optimization parameter number is performed. The preparation scheme is defined as a combination of several block pulses whose flip angles, phase terms and inter-pulse delays are optimized to control the magnetization evolution. RESULTS The proposed approach reduces the computation time of B 0 -robust preparation schemes to around a minute (whereas several hours were required with previous schemes), with negligible performance loss. …
Neuroprotective effects of behavioural training and nicotine on age-related deficits in spatial learning.
2006
Studies in humans and animals show a clear decline in spatial memory with age and several approaches have been adopted to alleviate this impairment. The purpose of our review is to assess the studies that have suggested the possible neuroprotective actions of behavioural training and nicotine-applied both independently and in conjunction-on age-related deficits in spatial learning. Both spatial pretraining and nonspatial experiences influence an animal's performance in spatial tasks. In aged rats, the experience of training in the water maze task increases the number of newly generated neurons in the hippocampus. The neuroprotective effects of nicotine have been demonstrated in both in-vitr…
Glutamate Activates Phospholipase D in Hippocampal Slices of Newborn and Adult Rats
1993
Phospholipase D (PLD) is activated by many neurotransmitters in a novel signal transduction pathway. In the present work, PLD activity was studied comparatively in hippocampal slices of newborn and adult rats. Basal PLD activity in adult rats was almost three times higher than in newborn rats. In newborn rats, L-glutamate and 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) time- and concentration-dependently enhanced the formation of [3H]phosphatidylpropanol ([3H]PP) and of [3H]phosphatidic acid in the presence of 2% propanol. N-Methyl-D-aspartate and kainate (both 1 mM) caused small, but significant increases (approximately 50%), whereas alpha-amino-3-hydroxy-5-methylisoxazole…
Impaired calcium homeostasis in aged hippocampal neurons
2009
Abstract Development of neurodegenerative diseases such as Alzheimer's and Parkinson's disease is strongly age-associated. The impairment of calcium homeostasis is considered to be a key pathological event leading to neuronal dysfunction and cell death. However, the exact impact of aging on calcium homeostasis in neurons remains largely unknown. In the present work we have investigated intracellular calcium levels in cultured primary hippocampal neurons from young (2 months) and aged (24 months) rat brains. Upon stimulation with glutamate or hydrogen peroxide aged neurons in comparison to young neurons demonstrated an increased vulnerability to these disease-related toxins. Measurement of c…