Neuroscience 2003 Abstract
| Presentation Number: | 143.25 |
|---|---|
| Abstract Title: | Effects of ß-catenin on dendritic morphology and simulated firing patterns in cultured hippocampal neurons. |
| Authors: |
Krichmar, J. L.*1
; Yu, X.2
; Velasquez, D.3
; Malenka, R. C.2
; Ascoli, G. A.3
1The Neurosci. Inst., San Diego, CA 2CA, 10640 John J. Hopkins Dr., 92121, 3USA, 10640 John J. Hopkins Dr., 92121, |
| Primary Theme and Topics |
Development - Axonal and Dendritic Development -- Dendritic growth and branching |
| Secondary Theme and Topics | Synaptic Transmission and Excitability<br />- Intrinsic Membrane Properties<br />-- Modulation and plasticity of intrinsic membrane properties |
| Session: |
143. Dendritic Growth & Branching I Poster |
| Presentation Time: | Sunday, November 9, 2003 8:00 AM-9:00 AM |
| Location: | Morial Convention Center - Hall F-I, Board # B54 |
| Keywords: | dendrite, modeling, burst, structure |
It has recently been demonstrated that ß-catenin plays a key role in dendritic morphogenesis (Yu and Malenka, SFN abs., 2003). Here, we examine the detailed morphological changes in the dendritic arbor of cultured hippocampal neurons elicited by overexpression of ß-catenin and simulate the electrophysiological consequences of these changes. Cells expressing a stabilized form of ß-catenin fused to GFP (GFP-ß-catenin) had significantly larger dendritic surface area and length than control cells. Other morphological measurements of size (i.e. bifurcations, termination tips, and branch order) revealed the same trend. To investigate the effect of GFP-ß-catenin expression on electrophysiological properties we converted digitized traces of cultured hippocampal neurons into the GENESIS computational simulator format using parameters which evenly distributed voltage-dependent channels across the cells’ membranes. In simulated current clamp experiments, somata were injected with a normalized current such that the observed electrophysiological differences in the neurons would only be due to morphological differences. We found that GFP-ß-catenin expressing neurons had significantly smaller action potential amplitude than control neurons. As a consequence, GFP-ß-catenin expressing neurons tended to exhibit short, high frequency bursts of action potentials (~90Hz) with an interburst interval of 250-1500 ms. Control neurons, in contrast, tended to spike regularly with single action potentials at 10-20 Hz. These findings show that by modifying dendritic arborization, ß-catenin may also have a profound influence on the electrophysiological behavior of neurons.
Supported by The Neurosciences Research Foundation and NIH NS39600
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
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