Search results for "Pyramidal cell"
showing 10 items of 51 documents
Functional Improvement after Photothrombotic Stroke in Rats Is Associated with Different Patterns of Dendritic Plasticity after G-CSF Treatment and G…
2016
We have previously shown that granulocyte-colony stimulating factor (G-CSF) treatment alone, or in combination with constraint movement therapy (CIMT) either sequentially or concomitantly, results in significantly improved sensorimotor recovery after photothrombotic stroke in rats in comparison to untreated control animals. CIMT alone did not result in any significant differences compared to the control group (Diederich et al., Stroke, 2012;43:185-192). Using a subset of rat brains from this former experiment the present study was designed to evaluate whether dendritic plasticity would parallel improved functional outcomes. Five treatment groups were analyzed (n = 6 each) (i) ischemic contr…
Lateral habenula and hippocampus: A complex interaction raphe cells-mediated
1997
The study has shown an excitatory influence exerted by lateral habenula (LH) on hippocampal pyramidal cells. The modulatory influence is paradoxically serotonine-mediated; in fact all LH stimulation effects were abolished by intrahippocampal iontophoretic methysergide application. The data suggest the involvement of dorsal raphe nucleus. In fact, the dorsal raphe nucleus stimulation caused on hippocampus an expected inhibitory effect antagonized by intrahippocampal iontophoretic methysergide application. In the context of this neural structure we have highlighted a disinhibitory relation between two types of cells: slow serotonergic efferent neurones and fast GABAergic interneurones. The di…
A model study for the progressive disruption of CA1 firing properties during Alzheimer’s disease
2011
Several independent studies show that β-Amyloid (Aβ) peptides accumulation, one of the characteristic hallmark of Alzheimer’s Disease (AD), can affect the normal neuronal activity in different ways causing an increase or a decrease in neuronal membrane excitability. For example, experimental evidence for a negative impact on neuronal membrane in animal models of AD has been obtained in dual patch recordings in rat hippocampal tissue slices, in which Aβ blocked K channels in pyramidal cell dendrites, causing an increase in dendritic membrane excitability. The resulting increased Ca2+ influx and excitoxicity may lead to dendritic degeneration. However, further experimental evidence suggests t…
Neocortical Layer 6B as a Remnant of the Subplate - A Morphological Comparison.
2015
The fate of the subplate (SP) is still a matter of debate. The SP and layer 6 (which is ontogenetically the oldest and innermost neocortical lamina) develop coincidentally. Yet, the function of sublamina 6B is largely unknown. It has been suggested that it consists partly of neurons from the transient SP, however, experimental evidence for this hypothesis is still missing. To obtain first insights into the neuronal complement of layer 6B in the somatosensory rat barrel cortex, we used biocytin stainings of SP neurons (aged 0-4 postnatal days, PND) and layer 6B neurons (PND 11-35) obtained during in vitro whole-cell patch-clamp recordings. Neurons were reconstructed for a quantitative charac…
Characterization of the cortical laser-doppler flow and hippocampal degenerative patterns after global cerebral ischaemia in the goat.
1998
Large-animal models offer several advantages in the study of cerebral ischaemia: easier control of physiological variables, easier neuropathological evaluation, etc. In the present study we have taken advantage of the unique cerebrovascular anatomy of the goat to reproduce a model of reversible, incomplete, global cerebral ischaemia in a large-sized animal species, in which the effects of successive manoeuvres to stop and re-start cerebral blood flow can be recorded continuously. Early cortical laser-Doppler flow response (up to 2 h) and delayed neuronal degeneration (7 days) in the hippocampal CA1 subfield have been analysed in goats undergoing 5, 10 or 20 min of transient, global cerebral…
Brain erythropoietin fine-tunes a counterbalance between neurodifferentiation and microglia in the adult hippocampus
2021
In adult cornu ammonis hippocampi, erythropoietin (EPO) expression drives the differentiation of new neurons,independent of DNA synthesis, and increases dendritic spine density. This substantial brain hardwareupgrade is part of a regulatory circle: during motor-cognitive challenge, neurons experience ‘‘functional’’hypoxia, triggering neuronal EPO production, which in turn promotes improved performance. Here, weshow an unexpected involvement of resident microglia. During EPO upregulation and stimulated neurodifferentiation,either by functional or inspiratory hypoxia, microglia numbers decrease. Treating mice with recombinanthuman (rh)EPO or exposure to hypoxia recapitulates these changes and…
Optical release of caged glutamate for stimulation of neurons in the in vitro slice preparation
2005
Optical stimulation techniques prove useful to map func- tional inputs in the in vitro brain slice preparation: Glutamate released by a focused beam of UV light induces action potentials, which can be detected in postsynaptic neurons. The direct activation effect is influenced by factors such as compound concentration, focus depth, light absorption in the tissue, and sensitivity of different neuronal do- mains. We analyze information derived from direct stimulation ex- periments in slices from rat barrel cortex and construct a computa- tional model of a layer V pyramidal neuron that reproduces the experimental findings. The model predictions concerning the influ- ence of focus depth on inpu…
Switching between persistent firing and depolarization block in individual rat CA1 pyramidal neurons
2018
The hippocampal formation plays a role in mnemonic tasks and epileptic discharges in vivo. In vitro, these functions and malfunctions may relate to persistent firing (PF) and depolarization block (DB), respectively. Pyramidal neurons of the CA1 field have previously been reported to engage in either PF or DB during cholinergic stimulation. However, it is unknown whether these cells constitute disparate populations of neurons. Furthermore, it is unclear which cell-specific peculiarities may mediate their diverse response properties. However, it has not been shown whether individual CA1 pyramidal neurons can switch between PF and DB states. Here, we used whole cell patch clamp in the current …
Phenotypic characterization of MCP-1 expressing neurons in the rat cerebral cortex.
2020
Chemokines are small, secreted molecules that mediate inflammatory reactions. Neurons and astrocytes constitutively express chemokines implicated in the process of neuroinflammation associated with neurodegenerative diseases. The monocyte chemoattractant protein-1 (MCP-1) has been widely related to this process. However, the constitutive expression of this molecule by neurons has not been elucidated so far. In this study, we set out to characterize the neurochemical phenotype of MCP-1-expressing neurons in the rat neocortex to infer its role in basal conditions. We observed the presence of two populations of neurons expressing MCP-1: One population of cells with weak expression of MCP-1 cor…
Special Features of the Hippocampal Formation with Respect to Seizure Conditions
1987
The hippocampus has long been known as a region particularly prone to epileptiform discharges (Kandel et al. 1961). Connections and physiology of this archaic cortical structure are relatively well charac-terized and a wealth of information on features favoring exaggerated neuronal activity has emerged in recent years. The lamellar organization of the hippo-campus (Andersen et al. 1971) may be one of these features; it certainly has facilitated their investigation. Tissue slices cut along the lamellae, perpendicular to the axis of the structure, contain a relatively undisturbed chain of neurons which can be rigorously investigated in vitro. The results from such experiments have allowed mod…