Homer proteins shape Xenopus optic tectal cell dendritic arbor development in vivo

Van Keuren-Jensen, K. R., Cline, H. T. (September 2008) Homer proteins shape Xenopus optic tectal cell dendritic arbor development in vivo. Developmental Neurobiology, 68 (11). pp. 1315-1324. ISSN 1932-846X

URL: http://www.ncbi.nlm.nih.gov/pubmed/18636533
DOI: 10.1002/dneu.20659

Abstract

Considerable evidence suggests that the Homer family of scaffolding proteins contributes to synaptic organization and function. We investigated the role of both Homer 1b, the constitutively expressed, and developmentally regulated form of Homer, and Homer 1a, the activity-induced immediate early gene, in dendritic arbor elaboration and synaptic function of developing Xenopus optic tectal neurons. We expressed exogenous Homer 1a or Homer 1b in developing Xenopus tectal neurons. By collecting in vivo time lapse images of individual, EGFP-labeled and Homer-expressing neurons over 3 days, we found that Homer 1b leads to a significant decrease in dendritic arbor growth rate and arbor size. Synaptic transmission was also altered in developing neurons transfected with Homer 1b. Cells expressing exogenous Homer 1b over 3 days had a significantly greater AMPA to NMDA ratios, and increased AMPA mEPSC frequency. These data suggest that increasing Homer 1b expression increases excitatory synaptic inputs, increases synaptic maturation, and slows dendritic arbor growth rate. Exogenous Homer 1a expression increases AMPA mEPSC frequency, but did not significantly affect tectal cell dendritic arbor development. Changes in the ratio of Homer 1a to Homer 1b may signal the neuron that overall activity levels in the cell have changed, and this in turn could affect protein interactions at the synapse, synaptic transmission, and structural development of the dendritic arbor. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.

Item Type: Paper
Subjects: organism description > animal > Frog
organism description > animal
organs, tissues, organelles, cell types and functions > cell types and functions > cell types
organs, tissues, organelles, cell types and functions > cell types and functions > cell types
organs, tissues, organelles, cell types and functions > cell types and functions > cell types

organs, tissues, organelles, cell types and functions > cell types and functions
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic arbors
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic arbors
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic arbors

organs, tissues, organelles, cell types and functions > tissues types and functions > visual cortex
organism description > animal > Frog > xenopus
CSHL Authors:
Communities: CSHL labs > Cline lab
Depositing User: Matt Covey
Date: 15 September 2008
Date Deposited: 26 Feb 2013 17:48
Last Modified: 26 Feb 2013 17:48
Related URLs:
URI: http://repository.cshl.edu/id/eprint/27543

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