Search results for "Dendrites"
showing 10 items of 54 documents
Characterization of a population of tyrosine hydroxylase-containing interneurons in the external plexiform layer of the rat olfactory bulb
2012
The olfactory bulb (OB) of mammals contains the major endogenous dopamine-producing system in the forebrain. The vast majority of dopaminergic neurons consists of juxtaglomerular cells, which innervate the olfactory glomeruli and modulate the entrance of sensory information to the OB. Although dopaminergic juxtaglomerular cells have been widely investigated, the presence of dopaminergic interneurons other than juxtaglomerular cells has been largely unexplored. In this study, we analyze a population of tyrosine hydroxylase (TH)-containing interneurons located in the external plexiform layer (EPL) of the rat OB. These interneurons are GABAergic and morphologically heterogeneous. They have an …
Streptozotocin diabetic mice display depressive-like behavior and alterations in the structure, neurotransmission and plasticity of medial prefrontal…
2015
Diabetes mellitus patients are at increased risk of developing depression, although the neurobiological bases of this comorbidity are not yet fully understood. These patients show CNS alterations, similar to those found in major depression, including changes in the structure and neurotransmission of excitatory neurons. However, although depressive patients and animal models also display alterations in inhibitory networks, little is known about the effects of diabetes on interneurons. Our main objective was to study the impact of diabetes on interneurons of the medial prefrontal cortex (mPFC), one of the regions most affected by major depression. For this purpose we have induced diabetes wit…
Short-term ischemia usually used for ischemic preconditioning causes loss of dendritic integrity after long-term survival in the gerbil hippocampus
2006
Ischemic preconditioning has been established as a powerful experimental neuroprotective strategy, both after global and focal cerebral ischemia. Little is known, however, about the structural and functional long-term outcome. Therefore, our present study was designed to check for potential subtle alterations in the hippocampus after long-term survival. Gerbils were subjected either to short-term ischemia of 2.5 min duration usually used for ischemic preconditioning (n=8) or to sham operation (n=6) and allowed to survive for 6 weeks. Hippocampi with neuronal densities comparable to those of sham-operated control animals were analyzed for dendritic marker proteins MAP2, MAP1B and synaptopodi…
Temporal coherency between receptor expression, neural activity and AP-1-dependent transcription regulates Drosophila motoneuron dendrite development.
2013
Neural activity has profound effects on the development of dendritic structure. Mechanisms that link neural activity to nuclear gene expression include activity-regulated factors, such as CREB, Crest or Mef2, as well as activity-regulated immediate-early genes, such as fos and jun. This study investigates the role of the transcriptional regulator AP-1, a Fos-Jun heterodimer, in activity-dependent dendritic structure development. We combine genetic manipulation, imaging and quantitative dendritic architecture analysis in a Drosophila single neuron model, the individually identified motoneuron MN5. First, Dα7 nicotinic acetylcholine receptors (nAChRs) and AP-1 are required for normal MN5 dend…
Mutations in KATNB1 Cause Complex Cerebral Malformations by Disrupting Asymmetrically Dividing Neural Progenitors
2014
SummaryExome sequencing analysis of over 2,000 children with complex malformations of cortical development identified five independent (four homozygous and one compound heterozygous) deleterious mutations in KATNB1, encoding the regulatory subunit of the microtubule-severing enzyme Katanin. Mitotic spindle formation is defective in patient-derived fibroblasts, a consequence of disrupted interactions of mutant KATNB1 with KATNA1, the catalytic subunit of Katanin, and other microtubule-associated proteins. Loss of KATNB1 orthologs in zebrafish (katnb1) and flies (kat80) results in microcephaly, recapitulating the human phenotype. In the developing Drosophila optic lobe, kat80 loss specificall…
Unusual target selectivity of perisomatic inhibitory cells in the hilar region of the rat hippocampus.
2000
Perisomatic inhibitory innervation of all neuron types profoundly affects their firing characteristics and vulnerability. In this study we examined the postsynaptic targets of perisomatic inhibitory cells in the hilar region of the dentate gyrus where the proportion of potential target cells (excitatory mossy cells and inhibitory interneurons) is approximately equal. Both cholecystokinin (CCK)- and parvalbumin-immunoreactive basket cells formed multiple contacts on the somata and proximal dendrites of mossy cells. Unexpectedly, however, perisomatic inhibitory terminals arriving from these cell types largely ignored hilar GABAergic cell populations. Eighty-ninety percent of various GABAergic…
Putative excitatory and putative inhibitory inputs are localised in different dendritic domains in aDrosophilaflight motoneuron
2012
Input-output computations of individual neurons may be affected by the three-dimensional structure of their dendrites and by the targeting of input synapses to specific parts of their dendrites. However, only few examples exist where dendritic architecture can be related to behaviorally relevant computations of a neuron. By combining genetic, immunohistochemical, and confocal laser scanning methods this study estimates the location of the spike initiating zone and the dendritic distribution patterns of putative synaptic inputs on an individually identified Drosophila flight motorneuron, MN5. MN5 is a monopolar neuron with more than 4000 dendritic branches. The site of spike initiation was e…
The Origin, Location, and Projections of the Embryonic Abdominal Motorneurons ofDrosophila
1997
We have used a retrograde labeling technique to identify motorneurons for each of the 30 body wall muscles of an abdominal hemisegment in the late stage 16Drosophilaembryo. Each motorneuron has a characteristic cell body position, dendritic arborization, and axonal projection. In addition, we have determined the neuroblasts of origin for most of the motorneurons we describe. Some organizational principles for the neuromuscular system have become apparent: (1) There is no obvious topographic relationship between the cell body positions of motorneurons and the position or orientation of the muscles they innervate; (2) motorneurons that innervate muscles of similar position and orientation are…
Dendritic Ih selectively blocks temporal summation of unsynchronized distal inputs in CA1 pyramidal neurons.
2004
The active dendritic conductances shape the input-output properties of many principal neurons in different brain regions, and the various ways in which they regulate neuronal excitability need to be investigated to better understand their functional consequences. Using a realistic model of a hippocampal CA1 pyramidal neuron, we show a major role for the hyperpolarization-activated current, I-h, in regulating the spike probability of a neuron when independent synaptic inputs are activated with different degrees of synchronization and at different distances from the soma. The results allowed us to make the experimentally testable prediction that the I-h in these neurons is needed to reduce ne…
Dscam1 Is Required for Normal Dendrite Growth and Branching But Not for Dendritic Spacing in Drosophila Motoneurons
2014
Down syndrome cell adhesion molecule, Dscam, serves diverse neurodevelopmental functions, including axon guidance and synaptic adhesion, as well as self-recognition and self-avoidance, depending on the neuron type, brain region, or species under investigation. InDrosophila, the extensive molecular diversity that results from alternative splicing of Dscam1 into >38,000 isoforms provides neurons with a unique molecular code for self-recognition in the nervous system. Each neuron produces only a small subset of Dscam1 isoforms, and distinct Dscam1 isoforms mediate homophilic interactions, which in turn, result in repulsion and even spacing of self-processes, while allowing contact with neig…