Search results for "hippocampal"
showing 10 items of 352 documents
Lack of APP and APLP2 in GABAergic Forebrain Neurons Impairs Synaptic Plasticity and Cognition.
2020
AbstractAmyloid-β precursor protein (APP) is central to the pathogenesis of Alzheimer’s disease, yet its physiological functions remain incompletely understood. Previous studies had indicated important synaptic functions of APP and the closely related homologue APLP2 in excitatory forebrain neurons for spine density, synaptic plasticity, and behavior. Here, we show that APP is also widely expressed in several interneuron subtypes, both in hippocampus and cortex. To address the functional role of APP in inhibitory neurons, we generated mice with a conditional APP/APLP2 double knockout (cDKO) in GABAergic forebrain neurons using DlxCre mice. These DlxCre cDKO mice exhibit cognitive deficits i…
A Golgi study of the short-axon interneurons of the cell layer and inner plexiform layer of the medial cortex of the lizardPodarcis hispanica
1997
The medial cortex of lizards is a three-layered brain region displaying cyto- and chemoarchitectonical, connectional, and ontogenetic characteristics that relate it to the hippocampal fascia dentata of mammals. Three interneuron types located in the cell layer and ten others in the inner plexiform layer (six in the juxtasomatic zone and four in the deep zone) are described in this study. The granuloid neurons, web-axon neurons, and deep-fusiform neurons lay within the cell layer. These neurons were scarce; they were probably gamma-aminobutyric acid (GABA)-, and parvalbumin-immunoreactive and presumably participated in feed forward as well as in feed back inhibition of the principal projecti…
Parvalbumin Interneurons and Perineuronal Nets in the Hippocampus and Retrosplenial Cortex of Adult Male Mice After Early Social Isolation Stress and…
2021
Both early life aversive experiences and intrinsic alterations in early postnatal neurodevelopment are considered predisposing factors for psychiatric disorders, such as schizophrenia. The prefrontal cortex and the hippocampus have protracted postnatal development and are affected in schizophrenic patients. Interestingly, similar alterations have been observed in the retrosplenial cortex (RSC). Studies in patients and animal models of schizophrenia have found alterations in cortical parvalbumin (PV) expressing interneurons, making them good candidates to study the etiopathology of this disorder. Some of the alterations observed in PV+ interneurons may be mediated by perineuronal nets (PNNs)…
Regulation of X Chromosome-Linked Inhibitor of Apoptosis Protein (XIAP) in Kainic Acid Induced Neuronal Cell Death in the Rat Hippocampus
2001
INTRODUCTION. Inhibitor of apoptosis protein (IAP) family consists of several antiapoptotic proteins conserved among species. The IAPs have a well-conserved motif of approximately 65 residues, called the baculovirus inhibitory repeat (BIR) (1). Baculovirus and drosophila IAPs have two, but most IAPs contain three BIR domains. Most of the IAPs also have a C-terminal RING domain which consists of conserved amino acids with zinc binding capacity. XIAP is one of the five known human IAPs and it binds directly and inhibits the activity of caspases (2). The BIR2 domain in XIAP is sufficient to mediate this inhibition (3). However little is known about the presence and function of XIAP in the nerv…
Calretinin/PSA-NCAM immunoreactive granule cells after hippocampal damage produced by kainic acid and DEDTC treatment in mouse.
2003
There is a dramatic increase in the number of lightly immunoreactive calretinin cells in the granular layer of the dentate gyrus of the mouse hippocampus 1 day after excitotoxic injury using kainic acid combined with the zinc chelator diethyldithiocarbamate. At 7 days after treatment, these cells are strongly immunoreactive for calretinin and for the polysialated form of the glycoprotein neural cell adhesion molecule (PSA-NCAM). The reexpression of calretinin and PSA-NCAM after treatment corresponds well with the loss of input from the damaged hilar mossy cells. These cells could be considered immature granule cells since they are immunoreactive to markers for immature cells such as PSA-NCA…
Optogenetically blocking sharp wave ripple events in sleep does not interfere with the formation of stable spatial representation in the CA1 area of …
2016
During hippocampal sharp wave/ripple (SWR) events, previously occurring, sensory inputdriven neuronal firing patterns are replayed. Such replay is thought to be important for plasticity-related processes and consolidation of memory traces. It has previously been shown that the electrical stimulation-induced disruption of SWR events interferes with learning in rodents in different experimental paradigms. On the other hand, the cognitive map theory posits that the plastic changes of the firing of hippocampal place cells constitute the electrophysiological counterpart of the spatial learning, observable at the behavioral level. Therefore, we tested whether intact SWR events occurring during th…
The expression mechanism of the residual LTP in the CA1 region of BDNF k.o. mice is insensitive to NO synthase inhibition
2011
Abstract BDNF and nitric oxide signaling both contribute to long-term potentiation (LTP) at glutamatergic synapses, but to date, few studies analyzed the interaction of both signaling cascades in the same synaptic pathway. Here we addressed the question whether the residual LTP in the CA1 region of hippocampal slices from heterozygous BDNF knockout mice (BDNF +/− ) is dependent on nitric oxide (NO) signaling. Extracellular recording of synaptic field potentials elicited by presynaptic Schaffer collateral stimulation was performed in the CA1 region of hippocampal slices of 4- to 6-week-old mice, and LTP was induced by a theta burst stimulation protocol. Application of the nitric oxide inhibi…
Cannabinoid CB1 Receptor Calibrates Excitatory Synaptic Balance in the Mouse Hippocampus
2015
The endocannabinoid system negatively regulates the release of various neurotransmitters in an activity-dependent manner, thereby influencing the excitability of neuronal circuits. In the hippocampus, cannabinoid type 1 (CB1) receptor is present on both GABAergic and glutamatergic axon terminals. CB1 receptor-deficient mice were previously shown to have increased hippocampal long-term potentiation (LTP). In this study, we have investigated the consequences of cell-type-specific deletion of the CB1 receptor on the induction of hippocampal LTP and on CA1 pyramidal cell morphology. Deletion of CB1 receptor in GABAergic neurons in GABA-CB1-KO mice leads to a significantly decreased hippocampal …
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 …
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. …