Topic
Nervous system
About: Nervous system is a research topic. Over the lifetime, 16729 publications have been published within this topic receiving 847181 citations.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: It is demonstrated that nerve cells that overexpress tagged α-synuclein can transmit the protein to neural stem cells in both in vitro and in vivo models, which could explain the remarkable finding that human embryonic dopamine nerve cells implanted into the striatum of patients with Parkinson's disease develop PD pathology with loss of dopamine markers and classic Lewy bodies.
Abstract: In this issue of PNAS, Desplats et al. (1) demonstrate that nerve cells that overexpress tagged α-synuclein can transmit the protein to neural stem cells in both in vitro and in vivo models. This important study could explain the remarkable finding that human embryonic dopamine nerve cells implanted into the striatum of patients with Parkinson's disease (PD) develop PD pathology with loss of dopamine markers and classic Lewy bodies (2, 3). It also provides insight into how α-synuclein pathology might sequentially spread throughout the nervous system in PD.
239 citations
••
TL;DR: Recent studies have identified molecular cues that activate intracellular signalling pathways in axons and mediate dynamic reorganization of the cytoskeleton to promote the formation of axon branches.
Abstract: The remarkable ability of a single axon to extend multiple branches and form terminal arbors enables vertebrate neurons to integrate information from divergent regions of the nervous system. Axons select appropriate pathways during development, but it is the branches that extend interstitially from the axon shaft and arborize at specific targets that are responsible for virtually all of the synaptic connectivity in the vertebrate CNS. How do axons form branches at specific target regions? Recent studies have identified molecular cues that activate intracellular signalling pathways in axons and mediate dynamic reorganization of the cytoskeleton to promote the formation of axon branches.
239 citations
••
TL;DR: It is shown that flies can perform complex brain functions in the absence of neural DA, whereas specific behaviors involving, in particular, arousal and choice require normal levels of this neuromodulator.
Abstract: The neuromodulatory function of dopamine (DA) is an inherent feature of nervous systems of all animals. To learn more about the function of neural DA in Drosophila, we generated mutant flies that lack tyrosine hydroxylase, and thus DA biosynthesis, selectively in the nervous system. We found that DA is absent or below detection limits in the adult brain of these flies. Despite this, they have a lifespan similar to WT flies. These mutants show reduced activity, extended sleep time, locomotor deficits that increase with age, and they are hypophagic. Whereas odor and electrical shock avoidance are not affected, aversive olfactory learning is abolished. Instead, DA-deficient flies have an apparently “masochistic” tendency to prefer the shock-associated odor 2 h after conditioning. Similarly, sugar preference is absent, whereas sugar stimulation of foreleg taste neurons induces normal proboscis extension. Feeding the DA precursor l-DOPA to adults substantially rescues the learning deficit as well as other impaired behaviors that were tested. DA-deficient flies are also defective in positive phototaxis, without alteration in visual perception and optomotor response. Surprisingly, visual tracking is largely maintained, and these mutants still possess an efficient spatial orientation memory. Our findings show that flies can perform complex brain functions in the absence of neural DA, whereas specific behaviors involving, in particular, arousal and choice require normal levels of this neuromodulator.
239 citations
••
TL;DR: In this review, recent advances in neurotrophin research are highlighted and their relevance to neurologic disease is discussed.
239 citations
••
TL;DR: These findings raise the possibility that exposure to environmental neurotoxins that affect cholinergic systems may seriously compromise brain development and have long-lasting morphologic, neurochemical, and functional consequences.
Abstract: In the adult nervous system, neurotransmitters mediate cellular communication within neuronal circuits. In developing tissues and primitive organisms, neurotransmitters subserve growth regulatory and morphogenetic functions. Accumulated evidence suggests that acetylcholine, (ACh), released from growing axons, regulates growth, differentiation, and plasticity of developing central nervous system neurons. In addition to intrinsic cholinergic neurons, the cerebral cortex and hippocampus receive extensive innervation from cholinergic neurons in the basal forebrain, beginning prenatally and continuing throughout the period of active growth and synaptogenesis. Acute exposure to ethanol in early gestation (which prevents formation of basal forebrain cholinergic neurons) or neonatal lesioning of basal forebrain cholinergic neurons, significantly compromises cortical development and produces persistent impairment of cognitive functions. Neonatal visual deprivation alters developmental expression of muscarinic acetylcholine receptors (mAChR) in visual cortex, whereas local infusion of mAChR antagonists impairs plasticity of visual cortical neurons. These findings raise the possibility that exposure to environmental neurotoxins that affect cholinergic systems may seriously compromise brain development and have long-lasting morphologic, neurochemical, and functional consequences.
239 citations