线虫(Caenorhabditis elegans)的神经回路仅由302个神经元组成,可称之为有一个“社会脑”的最简单的动物。当有细菌可吃时,“社会”类线虫便选择聚集在一起,但独行类线虫却不会这么做。
现在,一项新的研究工作发现RMG inter/motor神经元对是多个传感线索的集成及关于群居的决策中所涉及的神经计算的枢纽。RMG神经元处在一个“轮轴及轮辐”回路的中心,通过非突触“间隙连接”与相邻的传感神经元相连。这个回路控制神经元对信息素梯度的反应方式。(生物谷Bioon.com)
生物谷推荐原始出处:
Nature 458, 1171-1175 (30 April 2009) | doi:10.1038/nature07886
A hub-and-spoke circuit drives pheromone attraction and social behaviour in C. elegans
Evan Z. Macosko1, Navin Pokala1, Evan H. Feinberg1, Sreekanth H. Chalasani1, Rebecca A. Butcher2, Jon Clardy2 & Cornelia I. Bargmann1
1 Howard Hughes Medical Institute, Laboratory of Neural Circuits and Behavior, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA
2 Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
Innate social behaviours emerge from neuronal circuits that interpret sensory information on the basis of an individual's own genotype, sex and experience. The regulated aggregation behaviour of the nematode Caenorhabditis elegans, a simple animal with only 302 neurons, is an attractive system to analyse these circuits. Wild social strains of C. elegans aggregate in the presence of specific sensory cues, but solitary strains do not1, 2, 3, 4. Here we identify the RMG inter/motor neuron as the hub of a regulated circuit that controls aggregation and related behaviours. RMG is the central site of action of the neuropeptide receptor gene npr-1, which distinguishes solitary strains (high npr-1 activity) from wild social strains (low npr-1 activity); high RMG activity is essential for all aspects of social behaviour. Anatomical gap junctions connect RMG to several classes of sensory neurons known to promote aggregation, and to ASK sensory neurons, which are implicated in male attraction to hermaphrodite pheromones5. We find that ASK neurons respond directly to pheromones, and that high RMG activity enhances ASK responses in social strains, causing hermaphrodite attraction to pheromones at concentrations that repel solitary hermaphrodites. The coordination of social behaviours by RMG suggests an anatomical hub-and-spoke model for sensory integration in aggregation, and points to functions for related circuit motifs in the C. elegans wiring diagram.