Strube-Bloss Martin F, Brown Austin, Spaethe Johannes, Schmitt Thomas, Rössler Wolfgang
Department of Behavioral Physiology & Sociobiology, Theodor-Boveri-Institute of Bioscience, Biocenter University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Department of Molecular and Cellular Biology, University of Arizona, Life Sciences South Building, 1007 E. Lowell Street, Tucson, AZ, 85721, United States of America.
PLoS One. 2015 Sep 4;10(9):e0137413. doi: 10.1371/journal.pone.0137413. eCollection 2015.
To trigger innate behavior, sensory neural networks are pre-tuned to extract biologically relevant stimuli. Many male-female or insect-plant interactions depend on this phenomenon. Especially communication among individuals within social groups depends on innate behaviors. One example is the efficient recruitment of nest mates by successful bumblebee foragers. Returning foragers release a recruitment pheromone in the nest while they perform a 'dance' behavior to activate unemployed nest mates. A major component of this pheromone is the sesquiterpenoid farnesol. How farnesol is processed and perceived by the olfactory system, has not yet been identified. It is much likely that processing farnesol involves an innate mechanism for the extraction of relevant information to trigger a fast and reliable behavioral response. To test this hypothesis, we used population response analyses of 100 antennal lobe (AL) neurons recorded in alive bumblebee workers under repeated stimulation with four behaviorally different, but chemically related odorants (geraniol, citronellol, citronellal and farnesol). The analysis identified a unique neural representation of the recruitment pheromone component compared to the other odorants that are predominantly emitted by flowers. The farnesol induced population activity in the AL allowed a reliable separation of farnesol from all other chemically related odor stimuli we tested. We conclude that the farnesol induced population activity may reflect a predetermined representation within the AL-neural network allowing efficient and fast extraction of a behaviorally relevant stimulus. Furthermore, the results show that population response analyses of multiple single AL-units may provide a powerful tool to identify distinct representations of behaviorally relevant odors.
为了触发先天行为，感觉神经网络会预先进行调整以提取生物学相关刺激。许多雌雄之间或昆虫与植物之间的相互作用都依赖于这一现象。特别是社会群体中个体之间的交流依赖于先天行为。一个例子是成功的大黄蜂觅食者对巢穴伙伴的高效招募。返回的觅食者在巢穴中释放一种招募信息素，同时进行“舞蹈”行为以激活未就业的巢穴伙伴。这种信息素的主要成分是倍半萜类法尼醇。法尼醇是如何被嗅觉系统处理和感知的，尚未得到确定。很可能处理法尼醇涉及一种先天机制，用于提取相关信息以触发快速可靠的行为反应。为了验证这一假设，我们对100个触角叶（AL）神经元进行了群体反应分析，这些神经元是在活的大黄蜂工蜂中记录的，在反复用四种行为上不同但化学相关的气味剂（香叶醇、香茅醇、香茅醛和法尼醇）刺激下。分析确定了与主要由花朵释放的其他气味剂相比，招募信息素成分的独特神经表征。法尼醇在AL中诱导的群体活动使得能够可靠地将法尼醇与我们测试的所有其他化学相关气味刺激区分开来。我们得出结论，法尼醇诱导的群体活动可能反映了AL神经网络内的一种预先确定的表征，允许高效快速地提取行为相关刺激。此外，结果表明，对多个单个AL单元的群体反应分析可能提供一种强大的工具来识别行为相关气味的不同表征。
