Strengths and limitations of morphological and behavioral analyses in detecting dopaminergic deficiency in Caenorhabditis elegans.

This study focuses on methods of measuring neurodegeneration involving the dopaminergic system and the identification of compounds with actions that disrupt dopamine function in the model organism Caenorhabditis elegans. Several dopamine-mediated locomotory behaviors, Area Exploration, Body Bends, and Reversals, as well as Swimming-Induced Paralysis and learned 2-Nonanone Avoidance, were compared to determine the best behavioral method for screening purposes. These behavioral endpoints were also compared to morphological scoring of neurodegeneration in the dopamine neurons. We found that in adult worms, Area Exploration is more sensitive than the other behavioral methods for identifying DA-deficient locomotion and is comparable to neuromorphological scoring outputs. For larval stage worms, locomotion was an unreliable endpoint, and neuronal scoring appeared to be the best method. We compared the wild-type N2 strain to the commonly used dat-1p::GFP reporter strains BY200 and BZ555, and we further characterized the dopamine-deficient strains, cat-2 e1112 and cat-2 n4547. In contrast to published results, we found that the cat-2 strains slowed on food almost as much as N2s. Both showed decreased levels of cat-2 mRNA and DA content, rather than none, with cat-2 e1112 having the greatest reduction in DA content in comparison to N2. Finally, we compared and contrasted strengths, limitations, cost, and equipment needs for all primary methods for analysis of the dopamine system in C....
Source: Neurotoxicology - Category: Neurology Authors: Tags: Neurotoxicology Source Type: research