Mirror Movement-Like Defects in Startle Behavior of ZebrafishdccMutants Are Caused by Aberrant Midline Guidance of Identified Descending Hindbrain Neurons
| Autor: | Roshan A. Jain, Chi-Bin Chien, Hannah S. Bell, Michael Granato, Amy Lim |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Reflex
Startle DNA Complementary Movement disorders Genotype Mutant Mutation Missense Fluorescent Antibody Technique Stimulation Hindbrain Interneurons Neural Pathways medicine Animals Zebrafish Swimming Neurons Behavior Animal biology General Neuroscience fungi Chromosome Mapping Articles Anatomy Commissure biology.organism_classification Startle reaction Axons Rhombencephalon Genes DCC Phenotype nervous system Touch Larva Mutation Axon guidance medicine.symptom Neuroscience Gene Deletion |
| Zdroj: | The Journal of Neuroscience. 34:2898-2909 |
| ISSN: | 1529-2401 0270-6474 |
| Popis: | Mirror movements are involuntary movements on one side of the body that occur simultaneously with intentional movements on the contralateral side. Humans with heterozygous mutations in the axon guidance receptorDCCdisplay such mirror movements, where unilateral stimulation results in inappropriate bilateral motor output. Currently, it is unclear whether mirror movements are caused by incomplete midline crossing and reduced commissural connectivity ofDCC-dependent descending pathways or by aberrant ectopic ipsilateral axonal projections of normally commissural neurons. Here, we show that in response to unilateral tactile stimuli, zebrafishdccmutant larvae perform involuntary turns on the inappropriate body side. We show that these mirror movement-like deficits are associated with axonal guidance defects of two identified groups of commissural reticulospinal hindbrain neurons. Moreover, we demonstrate that indccmutants, axons of these identified neurons frequently fail to cross the midline and instead project ipsilaterally. Whereas laser ablation of these neurons in wild-type animals does not affect turning movements, their ablation indccmutants restores turning movements. Thus, our results demonstrate that indccmutants, turns on the inappropriate side of the body are caused by aberrant ipsilateral axonal projections, and suggest that aberrant ipsilateral connectivity of a very small number of descending axons is sufficient to induce incorrect movement patterns. |
| Databáze: | OpenAIRE |
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