Search results for "Calbindin"
showing 10 items of 26 documents
Expression of regulatory genes in the embryonic brain of a lizard and implications for understanding pallial organization and evolution
2017
The comparison of gene expression patterns in the embryonic brain of mouse and chicken is being essential for understanding pallial organization. However, the scarcity of gene expression data in reptiles, crucial for understanding evolution, makes it difficult to identify homologues of pallial divisions in different amniotes. We cloned and analyzed the expression of the genes Emx1, Lhx2, Lhx9, and Tbr1 in the embryonic telencephalon of the lacertid lizard Psammodromus algirus. The comparative expression patterns of these genes, critical for pallial development, are better understood when using a recently proposed six-part model of pallial divisions. The lizard medial pallium, expressing all…
PSA-NCAM expression in the human prefrontal cortex.
2006
The prefrontal cortex (PFC) of adult rodents is capable of undergoing neuronal remodeling and neuroimaging studies in humans have revealed that the structure of this region also appears affected in different psychiatric disorders. However, the cellular mechanisms underlying this plasticity are still unclear. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) may mediate these structural changes through its anti-adhesive properties. PSA-NCAM participates in neurite outgrowth and synaptogenesis and changes in its expression occur parallel to neuronal remodeling in certain regions of the adult brain. PSA-NCAM is expressed in the hippocampus and temporal cortex of adult hum…
Poorly differentiated synovial sarcoma: A case report
2001
Poorly differentiated synovial sarcoma is a rare soft tissue tumor. We studied a case arising in the pleural cavity of a young subject, characterised by the presence of spindle cell, small cell, and large epithelioid cell areas. We performed stains for mucosubstances and analysed the expression of cytokeratins 5/6, 7, 8, 18, 19, CEA, CD34, Ber-Ep4 and calretinin to characterize the phenotype of this neoplasm. We furthermore assessed immunohistochemically the presence of p53, Bcl-2, Bax and caspase 3, four apoptotic markers, to evaluate a relationship between apoptotic activity and the behaviour of this tumor. Our findings showed a strong presence of calretinin, p53 and Bcl-2 in all three ar…
An increase of hippocampal calretinin-immunoreactive neurons correlates with early febrile seizures in temporal lobe epilepsy
1999
Numerous studies indicate that initial precipi- tating injuries (IPI) such as febrile seizures during early childhood may play a pivotal role in the pathogenesis of temporal lobe epilepsy (TLE) and Ammon's horn sclero- sis (AHS). Previous data demonstrate an increase of hori- zontally oriented neurons in molecular layers of hip- pocampal subfields, which are immunoreactive for calre- tinin (CR-ir) and resemble Cajal-Retzius-like cells. Cajal- Retzius cells are transiently expressed in the murine de- veloping hippocampus and are critically involved in neu- ronal pattern formation. Here we investigated a potential relationship between the distribution of horizontally ori- ented calretinin-imm…
Glutamatergic projection from the nucleus incertus to the septohippocampal system
2012
Abstract Recent findings support a relevant role of the nucleus incertus in the control of the hippocampal activity through the modulation of theta rhythm. Previous studies from our group have shown that this nucleus is a critical relay between reticularis pontis oralis and the medial septum/diagonal band, regarded as the main activator and the pacemaker of the hippocampal oscillations, respectively. Besides, the nucleus incertus is highly linked to activated states related to the arousal response. The neurotransmission of the nucleus incertus, however, remains uncertain. Only GABA and the neuromodulator relaxin 3 are usually considered to be involved in its contribution to the septohippoca…
Soluble guanylyl cyclase appears in a specific subset of periglomerular cells in the olfactory bulb
2005
In the brain, nitric oxide acts as an atypical messenger in cellular nonsynaptic transmission. In the olfactory bulb, this gas is produced at the level of the olfactory glomeruli by a subpopulation of periglomerular cells that participates in the first synaptic relay of the olfactory information between the olfactory nerve and the dendritic tufts of principal cells. It has been proposed that nitric oxide modulates intraglomerular synaptic integration of sensory inputs, but its specific role in the glomerular circuitry remains to be understood. In this article, we demonstrate that, in the glomerular circuits, a specific subset of periglomerular cells, most of them expressing the calcium bind…
VIP-containing deep short-axon cells of the olfactory bulb innervate interneurons different from granule cells
2003
This study investigates the targets of the population of vasoactive intestinal polypeptide (VIP)-containing deep short-axon cells of the rat olfactory bulb (OB), combining single- and double-immunocytochemical approaches under light and electron microscopy. It has been assumed that deep short-axon cells innervate granule cells in the mammalian OB, but their synaptic connectivity has not been demonstrated to date. Our results indicate that, instead of the accepted scheme of the bulbar circuitry, VIP-containing deep short-axon cells are gamma-aminobutyric acid (GABA)ergic interneurons specialized in the selective innervation of other GABAergic deep short-axon cells. Their axons contact with t…
Loss of input from the mossy cells blocks maturation of newly generated granule cells.
2007
The objective of this work is to check whether the input from the mossy cells to the inner molecular layer is necessary for the integration and maturation of the newly generated granule cells of the dentate gyrus (DG) in mice, and if after status epilepticus the sprouting of the mossy fibers can substitute for this projection. Newly generated cells were labeled by administration of 5-bromo-deoxyuridine either before or after pilocarpine administration. The neuronal loss in the hippocampus after administration of pilocarpine combined with scopolamine and diazepam seemed restricted to the hilar mossy cells. The maturation of the granule cells was studied using immunohistochemistry for calreti…
Calcium-binding proteins in the dorsal ventricular ridge of the lizardPsammodromus algirus
1999
The aim of the present work was to study further the intrinsic organization of the dorsal ventricular ridge of lizards. For that purpose, the morphology and distribution of cells and fibers containing the calcium-binding proteins calbindin-D28k, parvalbumin, and calretinin were investigated by using immunohistochemical methods. Colocalization of calcium-binding proteins with the neurotransmitter gamma-aminobutyric acid (GABA) was also studied because they are shown to coexist in many areas of the telencephalon where they define distinct subpopulations of GABAergic local circuit neurons. Neurons containing calcium-binding proteins are limited to the anterior part of the dorsal ventricular ri…
Nrg1 haploinsufficiency alters inhibitory cortical circuits
2021
Neuregulin 1 (NRG1) and its receptor ERBB4 are schizophrenia (SZ) risk genes that control the development of both excitatory and inhibitory cortical circuits. Most studies focused on the characterization ErbB4 deficient mice. However, ErbB4 deletion concurrently perturbs the signaling of Nrg1 and Neuregulin 3 (Nrg3), another ligand expressed in the cortex. In addition, NRG1 polymorphisms linked to SZ locate mainly in non-coding regions and they may partially reduce Nrg1 expression. Here, to study the relevance of Nrg1 partial loss-of-function in cortical circuits we characterized a recently developed haploinsufficient mouse model of Nrg1 (Nrg1tm1Lex). These mice display SZ-like behavioral d…