Search results for "Hippocampus"
showing 10 items of 622 documents
Diffusion Tensor Imaging of the Hippocampus in MCI and Early Alzheimer's Disease
2011
The hippocampus is among the first brain structures to be affected by Alzheimer's disease (AD) pathology. Microstructural alterations within this region have been quantified in vivo using diffusion tensor imaging (DTI), a relatively novel MRI-based technique for mapping diffusion properties of water. Existing evidence indicates that DTI-derived mean diffusivity (MD) of the anterior hippocampus is more predictive than ordinary volumetric indices of the degree of episodic memory impairment in patients with early AD. Thus, altered MD of the (anterior) hippocampus might be highly indicative of hippocampal dysfunction, thereby potentially qualifying this measure as a candidate marker for monitor…
Nucleus incertus contribution to hippocampal theta rhythm generation.
2006
The hippocampal theta rhythm is generated by the pacemaker activity of the medial septum-diagonal band of Broca (MS/DBB) neurons. These nuclei are influenced by brainstem structures that modulate the theta rhythm. The aim of the present work is to determine whether the nucleus incertus (NI), which has important anatomical connections with the MS/DBB, contributes to the hippocampal theta rhythm generation in rats. Hippocampal field activity was recorded in urethane-anaesthetized rats. Electrical stimulation of the NI not only evoked theta rhythm in the hippocampus, but also decreased the amplitude of delta waves. Unit recordings in the NI revealed either a non-rhythm discharge pattern in mos…
Regional distribution of the leucine-rich glioma inactivated (LGI) gene family transcripts in the adult mouse brain
2009
25 p., figuras y bibliografía
Anti-inflammatory and antioxidant effects of muscarinic acetylcholine receptor (mAChR) activation in the rat hippocampus
2019
AbstractRecently we found that acute treatment with Oxotremorine (Oxo), a non-selective mAChRs agonist, up-regulates heat shock proteins and activates their transcription factor heat shock factor 1 in the rat hippocampus. Here we aimed to investigate: a) if acute treatment with Oxo may regulate pro-inflammatory or anti-inflammatory cytokines and oxidative stress in the rat hippocampus; b) if chronic restraint stress (CRS) induces inflammatory or oxidative alterations in the hippocampus and whether such alterations may be affected by chronic treatment with Oxo. In the acute experiment, rats were injected with single dose of Oxo (0.4 mg/kg) and sacrificed at 24 h, 48 h and 72 h. In the CRS ex…
Acute effects of antidepressant drugs on long-term potentiation (LTP) in rat hippocampal slices.
1991
The actions of three clinically effective antidepressant drugs with different pharmacological profiles were investigated in the CA1 area of rat hippocampal slices. Imipramine and (+) or (-)-oxaprotiline had negligible effects on population spikes evoked by stratum radiatum stimulation, but reduced postsynaptic excitability in low Ca high Mg medium after an exposure of more than 15 min. Imipramine and (+)-oxaprotiline at 10 mumol/l enhanced long-term potentiation (LTP) when a lower stimulation strength was applied while (+)-oxaprotiline reduced LTP when a higher stimulus amplitude was used to evoke population spikes. (-)-oxaprotiline (levoprotiline) had a similar effect which was, however, n…
Cue valence representation studied by Fos immunocytochemistry after acquisition of a discrimination learning task.
2003
The piriform cortex (PCx) and related structures such as hippocampus and frontal cortex could play an important role in olfactory memory. We investigated their involvement in learning the biological value of an odor cue, i.e. predicting reward or non-reward in a two-odor discrimination task. Rats were sacrificed after stimulation by either rewarded or non-rewarded odor and Fos immunocytochemistry was performed. The different experimental groups of rats did not show strongly differentiated Fos expression pattern in either the PCx or the hippocampus. A few differences were noted in frontal areas. In the ventro-lateral orbital cortex, rats, ramdomly rewarded during the conditionning had a high…
Harmonized benchmark labels of the hippocampus on magnetic resonance: The EADC-ADNI project
2015
Abstract Background A globally harmonized protocol (HarP) for manual hippocampal segmentation based on magnetic resonance has been recently developed by a task force from European Alzheimer's Disease Consortium (EADC) and Alzheimer's Disease Neuroimaging Initiative (ADNI). Our aim was to produce benchmark labels based on the HarP for manual segmentation. Methods Five experts of manual hippocampal segmentation underwent specific training on the HarP and segmented 40 right and left hippocampi from 10 ADNI subjects on both 1.5 T and 3 T scans. An independent expert visually checked segmentations for compliance with the HarP. Descriptive measures of agreement between tracers were intraclass cor…
A "double hit" murine model for schizophrenia shows alterations in the structure and neurochemistry of the medial prefrontal cortex and the hippocamp…
2013
Both alterations in neurodevelopment and aversive experiences during childhood and adolescence seem important risk factors for schizophrenia. Animal models reproducing these alterations mimic some of the symptoms, constituting a valid approach to study the etiopathology of this disorder. Among these models, the perinatal injection of N-methyl-d-aspartate receptor antagonists and the postweaning social isolation rearing are among the most widely used. Our aim is to combine them in a "double hit" model, which should produce a wider spectrum of alterations. Lister Hooded rats have been subjected to a single injection of MK-801 at postnatal day 7 and socially isolated from postweaning to adulth…
Non-granule PSA-NCAM immunoreactive neurons in the rat hippocampus
2002
The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) continues to be expressed in the adult hippocampus, mainly in a subset of neurons located in the innermost portion of the granule cell layer. PSA-NCAM immunoreactive neurons have also been described outside this layer in humans, where they are severely reduced in schizophrenic brains. Given this important clinical implication, we were interested in finding whether similar neurons existed in the adult rat hippocampus and to characterize their distribution, morphology and phenotype. PSA-NCAM immunocytochemistry reveals labeled neurons in the subiculum, fimbria, alveus, hilus, and stratum oriens, lucidum and radiatum of CA…
Hippocampal GABAergic Synapses Possess the Molecular Machinery for Retrograde Nitric Oxide Signaling
2007
Nitric oxide (NO) plays an important role in synaptic plasticity as a retrograde messenger at glutamatergic synapses. Here we describe that, in hippocampal pyramidal cells, neuronal nitric oxide synthase (nNOS) is also associated with the postsynaptic active zones of GABAergic symmetrical synapses terminating on their somata, dendrites, and axon initial segments in both mice and rats. The NO receptor nitric oxide-sensitive guanylyl cyclase (NOsGC) is present in the brain in two functional subunit compositions: α1β1and α2β1. The β1subunit is expressed in both pyramidal cells and interneurons in the hippocampus. Using immunohistochemistry andin situhybridization methods, we describe that the …