Ryglewski Stefanie, Kadas Dimitrios, Hutchinson Katie, Schuetzler Natalie, Vonhoff Fernando, Duch Carsten
Institute of Neurobiology, Johannes Gutenberg University of Mainz, 55099 Mainz, Germany.
Institute of Neurobiology, Johannes Gutenberg University of Mainz, 55099 Mainz, Germany
Proc Natl Acad Sci U S A. 2014 Dec 16;111(50):18049-54. doi: 10.1073/pnas.1416247111. Epub 2014 Dec 1.
Dendrites are highly complex 3D structures that define neuronal morphology and connectivity and are the predominant sites for synaptic input. Defects in dendritic structure are highly consistent correlates of brain diseases. However, the precise consequences of dendritic structure defects for neuronal function and behavioral performance remain unknown. Here we probe dendritic function by using genetic tools to selectively abolish dendrites in identified Drosophila wing motoneurons without affecting other neuronal properties. We find that these motoneuron dendrites are unexpectedly dispensable for synaptic targeting, qualitatively normal neuronal activity patterns during behavior, and basic behavioral performance. However, significant performance deficits in sophisticated motor behaviors, such as flight altitude control and switching between discrete courtship song elements, scale with the degree of dendritic defect. To our knowledge, our observations provide the first direct evidence that complex dendrite architecture is critically required for fine-tuning and adaptability within robust, evolutionarily constrained behavioral programs that are vital for mating success and survival. We speculate that the observed scaling of performance deficits with the degree of structural defect is consistent with gradual increases in intellectual disability during continuously advancing structural deficiencies in progressive neurological disorders.
树突是高度复杂的三维结构，它决定了神经元的形态和连接性，并且是突触输入的主要部位。树突结构缺陷与脑部疾病高度相关。然而，树突结构缺陷对神经元功能和行为表现的确切影响仍然未知。在这里，我们通过使用基因工具选择性地消除已鉴定的果蝇翅运动神经元中的树突，而不影响其他神经元特性，来探究树突的功能。我们发现，这些运动神经元树突对于突触靶向、行为期间定性正常的神经元活动模式以及基本行为表现而言出人意料地并非必需。然而，在复杂的运动行为中，如飞行高度控制和离散求偶歌曲元素之间的切换，显著的行为表现缺陷与树突缺陷程度相关。据我们所知，我们的观察提供了首个直接证据，即复杂的树突结构对于在强大的、受进化限制的行为程序中的微调与适应性至关重要，而这些行为程序对于交配成功和生存至关重要。我们推测，观察到的行为表现缺陷与结构缺陷程度相关，这与进行性神经疾病中结构缺陷不断进展时智力残疾逐渐增加是一致的。
