Search results for "campus"
showing 10 items of 667 documents
Reference standard space hippocampus labels according to the European Alzheimer's Disease Consortium–Alzheimer's Disease Neuroimaging Initiative harm…
2017
Abstract Introduction A harmonized protocol (HarP) for manual hippocampal segmentation on magnetic resonance imaging (MRI) has recently been developed by an international European Alzheimer's Disease Consortium–Alzheimer's Disease Neuroimaging Initiative project. We aimed at providing consensual certified HarP hippocampal labels in Montreal Neurological Institute (MNI) standard space to serve as reference in automated image analyses. Methods Manual HarP tracings on the high-resolution MNI152 standard space template of four expert certified HarP tracers were combined to obtain consensual bilateral hippocampus labels. Utility and validity of these reference labels is demonstrated in a simple …
Loss of spatial learning in a patient with topographical disorientation in new environments
2003
The case is described of a patient who, following cerebral hypoxia, developed severe difficulty in orienting himself in new environments in the context of a mild global amnesic syndrome. Some episodes he related suggested that his main difficulty was remembering the spatial/directional value of landmarks he recognised. A neuroradiological examination documented severe bilateral atrophy of the hippocampi associated with atrophic changes in the cerebral hemispheres, most marked in the dorsal regions. Neuropsychological and experimental evaluation showed a severe deficit of spatial learning with substantially preserved ability to learn verbal and visual-object information. He was also virtuall…
Generalization of seizures parallels the formation of "dark" neurons in the hippocampus and pontine reticular formation after focal-cortical applicat…
2008
Abstract Distribution and time course of the occurrence of “dark” neurons were compared with the EEG activity and behavior of rats during 4-aminopyridine (4-AP) induced epileptic seizures. A crystal of the K + channel blocker 4-AP (0.5 mg/kg) was placed onto the exposed parieto-occipital cortex of Halothane-anesthetized rats for 40 min. Thereafter, the anesthesia was discontinued and the behavioral signs of the epileptic seizure activity were observed. The presence of “dark” neurons was demonstrated by the sensitive silver method of Gallyas in rats sacrificed at 0, 3 and 6 h after the end of the 4-AP crystal application. The EEG activity was recorded in the rats with longer survival times. …
Involvement of TRPV1 channels in the activity of the cannabinoid WIN 55,212-2 in an acute rat model of temporal lobe epilepsy
2016
The exogenous cannabinoid agonist WIN 55,212-2, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN), has revealed to play a role on modulating the hyperexcitability phenomena in the hippocampus. Cannabinoid-mediated mechanisms of neuroprotection have recently been found to imply the modulation of transient receptor potential vanilloid 1 (TRPV1), a cationic channel subfamily that regulate synaptic excitation. In our study, we assessed the influence of pharmacological manipulation of TRPV1 function, alone and on WIN antiepileptic activity, in the Maximal Dentate Activation (MDA) acute model of temporal lobe epilepsy. Our r…
Neuroprotective action of diazepam at very low and moderate doses in Alzheimer's disease model rats
2018
Abstract Early manifestations of Alzheimer's disease (AD) include neuroinflammation, disrupted neurotransmission and cognitive deficits. Impairment of the GABAergic system is essentially involved in the pathogenesis of AD. Traditionally, agonists of GABAA receptors at doses above 1 mg/kg are known to possess memory impairing effects. However, we have previously found that GABAA receptor GABA site ligand muscimol at very low doses acted contrary – enhanced spatial learning/memory, as well as prevented neuroinflammation and augmented neurotransmission in AD model rats. Therefore, in the present study we focused on the assessment of the effects of non-sedative – very low (0.05 mg/kg) and moder…
Neural stem cell lineage-specific cannabinoid type-1 receptor regulates neurogenesis and plasticity in the adult mouse hippocampus
2018
Abstract Neural stem cells (NSCs) in the adult mouse hippocampus occur in a specific neurogenic niche, where a multitude of extracellular signaling molecules converges to regulate NSC proliferation as well as fate and functional integration. However, the underlying mechanisms how NSCs react to extrinsic signals and convert them to intracellular responses still remains elusive. NSCs contain a functional endocannabinoid system, including the cannabinoid type-1 receptor (CB1). To decipher whether CB1 regulates adult neurogenesis directly or indirectly in vivo, we performed NSC-specific conditional inactivation of CB1 by using triple-transgenic mice. Here, we show that lack of CB1 in NSCs is su…
Memory-enhancing and brain protein expression-stimulating effects of novel calcium antagonist in Alzheimer’s disease transgenic female mice
2016
The prevalence of Alzheimer's disease (AD) is higher in females than in males, and causes more severe cognitive, memory and behavioral impairments. Previously, in male transgenic (Tg) APPSweDI mice, we reported that the novel lipophilic 1,4-dihydropyridine (DHP) derivative AP-12 crossed the blood-brain barrier, blocked neuronal and vascular calcium channels, changed brain protein expression and improved behavior. In this study, we used female Tg APPSweDI mice to assess the effects of AP-12 on behavior, and brain protein expression, with a particular focus on those of the GABAergic system. The results showed that in female Tg mice, similar to male Tg mice, AP-12 improved spatial learning/mem…
Effects of the Antidepressant Fluoxetine on the Somatostatin Interneurons in the Basolateral Amygdala
2018
Although the precise mechanism of action of antidepressant drugs remains elusive, the neuroplastic hypothesis has gained acceptance during the last two decades. Several studies have shown that treatment with antidepressants such as Fluoxetine is associated with enhanced plasticity in control animals, especially in regions such as the visual cortex, the hippocampus and the medial prefrontal cortex. More recently, the basolateral amygdala has been shown to be affected by Fluoxetine leading to a reopening of critical period-like plasticity in the fear and aggression circuits. One of the key elements triggering this type of brain plasticity are inhibitory networks, especially parvalbumin intern…
Exercise and probiotics attenuate the development of Alzheimer's disease in transgenic mice: Role of microbiome
2018
Abstract It has been suggested that exercise training and probiotic supplementation could decelerate the progress of functional and biochemical deterioration in APP/PS1 transgenic mice (APP/PS1TG). APP/PS1TG mice were subjected to exercise training and probiotic treatments and functional, biochemical and microbiome markers were analyzed. Under these conditions the mice significantly outperformed controls on The Morris Maze Test, and the number of beta-amyloid plaques decreased in the hippocampus. B. thetaiotaomicron levels correlated highly with the results of the Morris Maze Test (p
Existence of muscarinic acetylcholine receptor (mAChR) and fibroblast growth factor receptor (FGFR) heteroreceptor complexes and their enhancement of…
2017
Abstract Background Recently, it was demonstrated that G-protein-coupled receptors (GPCRs) can transactivate tyrosine kinase receptors in absence of their ligands. In this work, driven by the observation that mAChRs and fibroblast growth factor receptors (FGFRs) share signalling pathways and regulation of brain functions, it was decided to explore whether mAChRs activation may transactivate FGFRs and, if so, to characterize the related trophic effects in cultured hippocampal neurons. Methods Oxotremorine-M transactivation of FGFRs and related trophic effects were tested in primary hippocampal neurons. Western blotting and in situ proximity ligation assay (PLA) were used to detect FGFR phosp…