Search results for "Interneurons"
showing 10 items of 79 documents
Progressive derivation of serially homologous neuroblast lineages in the gnathal CNS of Drosophila
2018
Along the anterior-posterior axis the central nervous system is subdivided into segmental units (neuromeres) the composition of which is adapted to their region-specific functional requirements. In Drosophila melanogaster each neuromere is formed by a specific set of identified neural stem cells (neuroblasts, NBs). In the thoracic and anterior abdominal region of the embryonic ventral nerve cord segmental sets of NBs resemble the ground state (2nd thoracic segment, which does not require input of homeotic genes), and serial (segmental) homologs generate similar types of lineages. The three gnathal head segments form a transitional zone between the brain and the ventral nerve cord. It has be…
The activation of NMDA receptors alters the structural dynamics of the spines of hippocampal interneurons
2017
N-Methyl-d-Aspartate receptors (NMDARs) are present in both pyramidal neurons and interneurons of the hippocampus. These receptors play a key role in the structural plasticity of excitatory neurons, but to date little is known about their influence on the remodeling of interneurons. Among hippocampal interneurons, the somatostatin expressing cells in the CA1 stratum oriens are of special interest because of their functional importance and structural characteristics: they display dendritic spines, which change their density in response to different stimuli. In order to understand the role of NMDAR activation on the structural dynamics of the spines of somatostatin expressing interneurons in …
NMDA Receptors Regulate the Structural Plasticity of Spines and Axonal Boutons in Hippocampal Interneurons
2017
N-methyl-D-aspartate receptors (NMDARs) are present in both pyramidal neurons and interneurons of the hippocampus. These receptors play an important role in the adult structural plasticity of excitatory neurons, but their impact on the remodeling of interneurons is unknown. Among hippocampal interneurons, somatostatin-expressing cells located in the stratum oriens are of special interest because of their functional importance and structural characteristics: they display dendritic spines, which change density in response to different stimuli. In order to understand the role of NMDARs on the structural plasticity of these interneurons, we have injected acutely MK-801, an NMDAR antagonist, to …
Increased Motor-Impairing Effects of the Neuroactive Steroid Pregnanolone in Mice with Targeted Inactivation of the GABAA Receptor γ2 Subunit in the …
2016
Endogenous neurosteroids and neuroactive steroids have potent and widespread actions on the brain via inhibitory GABAA receptors. In recombinant receptors and genetic mouse models their actions depend on the α, β, and δ subunits of the receptor, especially on those that form extrasynaptic GABAA receptors responsible for non-synaptic (tonic) inhibition, but they also act on synaptically enriched γ2 subunit-containing receptors and even on αβ binary receptors. Here we tested whether behavioral sensitivity to the neuroactive steroid agonist 5β-pregnan-3α-ol-20-one is altered in genetically engineered mouse models that have deficient GABAA receptor-mediated synaptic inhibition in selected neuro…
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…
Reduced interneuronal dendritic arborization in CA1 but not in CA3 region of mice subjected to chronic mild stress
2016
Abstract Introduction Chronic stress induces dendritic atrophy and decreases spine density in excitatory hippocampal neurons, although there is also ample evidence indicating that the GABAergic system is altered in the hippocampus after this aversive experience. Chronic stress causes dendritic remodeling both in excitatory neurons and interneurons in the medial prefrontal cortex and the amygdala. Methods In order to know whether it also has an impact on the structure and neurotransmission of hippocampal interneurons, we have analyzed the dendritic arborization, spine density, and the expression of markers of inhibitory synapses and plasticity in the hippocampus of mice submitted to 21 days …
A screen for constituents of motor control and decision making in Drosophila reveals visual distance-estimation neurons
2016
AbstractClimbing over chasms larger than step size is vital to fruit flies, since foraging and mating are achieved while walking. Flies avoid futile climbing attempts by processing parallax-motion vision to estimate gap width. To identify neuronal substrates of climbing control, we screened a large collection of fly lines with temporarily inactivated neuronal populations in a novel high-throughput assay described here. The observed climbing phenotypes were classified; lines in each group are reported. Selected lines were further analysed by high-resolution video cinematography. One striking class of flies attempts to climb chasms of unsurmountable width; expression analysis guided us to C2 …
Maternal inflammation has a profound effect on cortical interneuron development in a stage and subtype-specific manner
2018
AbstractSevere infections during pregnancy are one of the major risk factors for cognitive impairment in the offspring. It has been suggested that maternal inflammation leads to dysfunction of cortical GABAergic interneurons that in turn underlies cognitive impairment of the affected offspring. However, the evidence comes largely from studies of adult or mature brains and how the impairment of inhibitory circuits arises upon maternal inflammation is unknown. Here we show that maternal inflammation affects multiple steps of cortical GABAergic interneuron development, i.e., proliferation of precursor cells, migration and positioning of neuroblasts, as well as neuronal maturation. Importantly,…
Spinal plasticity with motor imagery practice.
2019
KEY POINTS: While a consensus has now been reached on the effect of motor imagery (MI) – the mental simulation of an action – on motor cortical areas, less is known about its impact on spinal structures. The current study, using H‐reflex conditioning paradigms, examined the effect of a 20 min MI practice on several spinal mechanisms of the plantar flexor muscles. We observed modulations of spinal presynaptic circuitry while imagining, which was even more pronounced following an acute session of MI practice. We suggested that the small cortical output generated during MI may reach specific spinal circuits and that repeating MI may increase the sensitivity of the spinal cord to its effects. T…
Neural stem cells in the adult olfactory bulb core generate mature neurons in vivo.
2021
17 páginas, 7 figuras.