Enthorhinal cortex

Associations between pathophysiological events and cognitive measures provide insights regarding brain networks affected during the clinical progression of Alzheimer's disease (AD). In this study, we assessed patients' scores in two delayed episodic memory tests, and investigated their associations with regional amyloid deposition and brain metabolism across the clinical spectrum of AD. We assessed the clinical, neuropsychological, structural, and positron emission tomography (PET) baseline measures of participants from the Alzheimer's Disease Neuroimaging Initiative...

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neurostimulation technique for the treatment of various neurological and psychiatric disorders. To investigate the working mechanism of this treatment approach, we designed a small-animal coil for dedicated use in rats and we combined this neurostimulation method with small-animal positron emission tomography (microPET or μPET) to quantify regional 2-deoxy-2-((18)F)fluoro-d-glucose ([(18)F]-FDG) uptake in the rat brain, elicited by a low- (1 Hz) and a high- (50 Hz) frequency paradigm...

Enhanced memory for emotional faces is a significant component of adaptive social interactions, but little is known on its neural developmental correlates. We explored the role of amygdaloid complex (AC) and medial temporal lobe (MTL) in emotional memory recognition across development, by comparing fMRI activations of successful memory encoding of fearful and neutral faces in children (n = 12; 8-12 years) and adolescents (n = 12; 13-17 years). Memory for fearful faces was enhanced compared with neutral ones in adolescents, as opposed to children...

BACKGROUND: The endocannabinoid 2-arachidonoyl glycerol (2-AG) acts as a retrograde messenger and modulates synaptic signaling e. g. in the hippocampus. 2-AG also exerts neuroprotective effects under pathological situations. To better understand the mechanism beyond physiological signaling we used Organotypic Entorhino-Hippocampal Slice Cultures (OHSC) and investigated the temporal regulation of 2-AG in different cell subsets during excitotoxic lesion and dendritic lesion of long range projections in the enthorhinal cortex (EC), dentate gyrus (DG) and the cornu ammonis region 1 (CA1)...

Dietary lipids modify brain fatty acid profile, but evidence of their direct effect on neuronal function is sparse. The enthorinal cortex (EC) neurons connecting to the hippocampus play a critical role in learning and memory. Here, we have exposed mice to diets based on canola:soybean oils (40 : 10, g/kg) or safflower : corn oils (25 : 25, g/kg) to investigate the relationship between the lipid profile of brain fatty acids and the intrinsic properties of EC neurons. Consumption of canola : soybean oil-enriched diet led to the increase of the monounsaturated fatty acid oleic acid and to a decrease of arachidonic acid in ethanolamine glycerophospholipids of the white matter...

For more than a decade, spinal cord stimulation (SCS) has been used as an adjuvant treatment for patients who are unresponsive to conventional therapies for angina pectoris. Many studies showed that SCS has both electro-analgesic and anti-ischemic effects. Nonetheless, the biological substrates by which SCS acts have not yet been unraveled, although recently areas in the brain have been described that show changes in blood flow, following SCS, and during provocation of angina. In search of a putative mechanism of action of SCS, we hypothesized that SCS affects processing of nociceptive information within the central nervous system (CNS)...

Female mice are more susceptible to radiation-induced cognitive changes than male mice. Previously, we showed that, in female mice, androgens antagonize age-related cognitive decline in aged wild-type mice and androgens and selective androgen receptor modulators (SARMs) antagonize cognitive changes induced by human apolipoprotein E4, a risk factor for developing age-related cognitive decline. In this study, the potential effects of the SARM ACP-105 were assessed in female mice that were either sham-irradiated or irradiated with ¹³⁷Cesium at a dose of 10Gy...

We examined whether acute administration of phencyclidine (PCP), an antagonist of the N-methyl-D-aspartate (NMDA) receptor-channel complex, can cause neuronal toxicity that is associated with apoptosis. Three- and 24-month-old rats were placed in locomotor activity chambers. PCP (50 mg/kg) or saline (0.15 M NaCl) were simultaneously administered to the treated and age-matched controls. After observing changes of locomotor activities, the animals were killed 24 h after treatment. The brains were processed for in situ analysis of apoptosis either by propidium iodide (PI) staining, or for the terminal dUTP nick-end labelling (TUNEL) method...

Previously we found apoE isoform-dependent effects of (137)Cs irradiation on cognitive function of female mice 3 months following irradiation. Alterations in the number of immature neurons and in the levels of the dendritic marker microtubule-associated protein 2 (MAP-2) might contribute to the cognitive changes following irradiation. Therefore, in the present study we determined if, following (137)Cs irradiation, there are apoE isoform-dependent effects on loss of doublecortin-positive neuroprogenitor cells or MAP-2 immumonoreactivity...

Here, we examine morphological changes in cortical thickness of patients with Alzheimer's disease (AD) using image analysis algorithms for brain structure segmentation and study automatic classification of AD patients using cortical and volumetric data. Cortical thickness of AD patients (n=14) was measured using MRI cortical surface-based analysis and compared with healthy subjects (n=20). Data was analyzed using an automated algorithm for tissue segmentation and classification. A Support Vector Machine (SVM) was applied over the volumetric measurements of subcortical and cortical structures to separate AD patients from controls...

With the rise in methamphetamine (MA) use among women of childbearing age, the potential consequences of MA exposure to the developing brain for cognition in adulthood is a major concern. Histamine might mediate these MA effects. Following MA administration in neonatal mice, histamine levels in brain were elevated and the hypothalamic-pituitary-adrenal axis was activated. Co-administration of MA with the H3 receptor agonist immepip antagonized these effects. The effects of MA on histamine levels and on hypothalamic-pituitary-adrenal axis activation at P20 were more pronounced in female than male mice...

The large number of transgenic mice realized thus far with different purposes allows addressing new questions, such as which animals, over the entire set of transgenic animals, show a specific behavioural abnormality. In the present study, we have used a metanalytical approach to organize a database of genetic modifications, brain lesions and pharmacological interventions that increase locomotor activity in animal models. To further understand the resulting data set, we have organized a second database of the alterations (genetic, pharmacological or brain lesions) that reduce locomotor activity...

The neuropeptide CART (cocaine and amphetamine regulated transcript) is suggested to be regulated by psychostimulant administration. We review here the localization of CART mRNA expression in the human brain and its possible relevance to human cocaine abuse. Except for strong hypothalamic expression, the CART transcript is predominately expressed in target regions of the mesocorticolimbic dopamine system, such as the nucleus accumbens shell, amygdala complex, extended amygdala and orbitofrontal, enthorhinal and piriform cortices...

In the mammalian olfactory system, oscillations related to odour representation have been described in field potential activities. Previous results showed that in olfactory bulb (OB) of awake rats engaged in an olfactory learning, odour presentation produced a decrease of oscillations in gamma frequency range (60-90 Hz) associated with a power increase in beta frequency range (15-40 Hz). This response pattern was strongly amplified in trained animals. The aim of this work was twofold: whether learning also induces similar changes in OB target structures and whether such OB response depends on its centrifugal inputs...

The objective of the present study was to examine whether neurofibrillary tangles densities are increased in elderly patients with late-onset schizophrenia (LOS). A neuropathological examination was performed in 32 consecutive autopsy brain specimens of ten patients with early-onset schizophrenia (EOS; onset of symptoms before the age of 40 years), eight patients with LOS (onset of symptoms after the age of 40 years) and 14 age-matched controls with no known neuropsychiatric disorder. Neurofibrillary tangle densities observed in the CA1 field of the hippocampus, the enthorhinal cortex, and the inferior temporal cortex in patients with LOS, EOS, and controls were not significantly different...

Viral tropism refers to the ability of a virus to selectively infect a given subset of cells. It relies on a variety of viral and host determinants that entail virus binding and entry into target cells, in addition to the presence of genetic elements that allow or enhance viral gene expression in a specific manner. Here we report the results of neuroanatomical studies in rat brains injected in different cerebral structures with vectors derived from the canine adenovirus type 2 (CAV2), whose natural target is the respiratory epithelium...

The brain localization of the neurotensin receptor NTS2 was studied with [3H]levocabastine, using an autoradiographic procedure. This study suggests that NTS2 receptors are mainly intracellular. High densities of binding sites were observed in the cingulate, insular, temporal, occipital, enthorhinal cortex, amygdaloid complex, septohippocampal nuclei, medial thalamus, mammillary bodies and superior colliculi; a moderate labelling was observed in the anterior and medial hippocampus, olfactory tubercle, hypothalamus, periaqueductal gray matter, caudate putamen, nucleus accumbens, septum, lateral thalamus, dorsal raphe nucleus and cerebellum; finally, a low labelling was apparent in the ventral tegmentum area and substantia nigra...

Patients with absence epilepsy frequently develop convulsions later in life. We were therefore interested whether tissue from rats with a genetic absence epilepsy is more prone to seizure generation than normal animals. We compared the epileptiform activities induced by 4-aminopyridine (4-AP) induced in hippocampal-entorhinal cortex slices from genetic absence epilepsy rats of Strasbourg (GAERS, age 6 months) in which absence seizures have been present for about 4 months and from control non epileptic rats (NE)...

The distribution of constitutively expressed mRNA encoding 2 isoforms of heat shock protein 90 (HSP90) was investigated in adult rat brain by in situ hybridization with 35S-labeled cRNA probes. HSP90 mRNA density was estimated by semiquantitative autoradiography and by microscopic analysis. The distribution of HSP90 transcripts was similar for the 2 probes. HSP90 mRNA was widespread but not ubiquitous, and labeling intensity varied among different regions. In particular, HSP90 mRNA was abundant in limbic system-related structures, such as the hippocampus, amygdala, mamillary body, piriform cortex, enthorhinal cortex, bed nucleus of the stria terminalis, medial habenular nucleus, and preoptic hypothalamic nuclei...

It has been established that hippocampus, enthorhinal cortex, amygdala and substantia nigra (pars reticulata) lesions before head injury lead to a decrease of kainic acid-induced behavioral and electrographic seizure expressions. It can be concluded that after head injury the activation of limbic structures excitability due to excitation of "inputs" to these formations takes place. The obtained data indicate the significant role of nucleus caudatus in activation of posttraumatic brain excitatory mechanisms.