Activity Affects Dendritic Shape and Synapse Elimination during Steroid Controlled Dendritic Retraction inManduca sexta
Year: 2004
Type: article
Abstract: Insect metamorphosis is a compelling example for dendritic and synaptic remodeling as larval and adult behaviors place distinct demands on the CNS. During the metamorphosis of the moth, Manduca sexta, many larval motoneurons are remodeled to serve a new function in the adult. During late larval life, steroid hormones trigger axonal and dendritic regression as well as larval synapse elimination. These regressive events are accompanied by stereotypical changes in motor behavior during the so-called wandering stages. Both normally occurring changes in dendritic shape and in motor output have previously been analyzed quantitatively for the individually identified motoneuron MN5. This study tested whether activity affected steroid-induced dendritic regression and synapse disassembly in MN5 by means of chronically implanted extracellular electrodes. Stimulating MN5 in vivo in intact, normally developing animals during a developmental period when it usually shows no activity significantly slowed the regression of high-order dendrites. Both physiological and anatomical analysis demonstrated that reduced dendritic regression was accompanied by a significant reduction in larval synapse disassembly. Therefore, steroid-induced alterations of dendritic shape and synaptic connectivity are modified by activity-dependent mechanisms. This interaction might be a common mechanism for rapid adjustments of rigid, inflexible, hormonal programs.
Source: Journal of Neuroscience
Authors: Carsten Duch, Tim Mentel
Institution: Freie Universität Berlin
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: hybrid
Funder: Deutsche Forschungsgemeinschaft
Award: G6482936760
OpenAlex ID: W2021604226