Mustaparta H
Department of Zoology, University of Trondheim-AVH, Dragvoll, Norway.
Chem Senses. 1996 Apr;21(2):269-75. doi: 10.1093/chemse/21.2.269.
An advantage of using pheromones in olfactory studies is that they are chemical signals for which receptor neurons are evolved and thus elicit biologically relevant odour-information to be processed in the brain. In many vertebrate and insect species, the olfactory system is separated into a 'main' and an 'accessory' division, the latter mediating pheromone information. In moths, the pheromone information is first processed in the brain in a large and sexually dimorphic structure, the macroglomerular complex (MGC) of the antennal lobe (AL). Also in vertebrates the pheromone information is processed in specific or modified glomerular complexes. One principle question is whether individual olfactory glomeruli are functional units, processing specific information concerning both the chemical quality and spatiotemporal features of the stimulus, like the pheromone plume. Indeed it has been shown that the axons of different pheromone-selective receptor neurons project into different MGC-glomeruli. Intracellular recordings from the AL projection (output) neurons also show that information about single components of the pheromone blend is preserved in some output pathways, whereas other output neurons respond in a unique fashion to the blend. The information about interspecific signals, which interrupts pheromone attraction, is processed in a specific MGC-glomerulus and is to a large extent kept separate from the pheromone information throughout the AL. Many of the output neurons accurately encode changes in the temporal characteristics of the stimulus.
在嗅觉研究中使用信息素的一个优势在于，它们是受体神经元已经进化出对应机制的化学信号，因此能够引发具有生物学相关性的气味信息，并在大脑中进行处理。在许多脊椎动物和昆虫物种中，嗅觉系统分为“主要”和“辅助”两个部分，后者负责介导信息素信息。在蛾类中，信息素信息首先在大脑中一个大型的、具有性别二态性的结构——触角叶（AL）的大glomerular复合体（MGC）中进行处理。在脊椎动物中，信息素信息也在特定的或经过修饰的glomerular复合体中进行处理。一个主要问题是，单个嗅觉glomeruli是否是功能单元，处理与刺激的化学性质和时空特征（如信息素羽流）相关的特定信息。事实上，已经表明不同信息素选择性受体神经元的轴突投射到不同的MGC - glomeruli中。来自AL投射（输出）神经元的细胞内记录还表明，关于信息素混合物单个成分的信息在一些输出途径中得以保留，而其他输出神经元则以独特的方式对混合物做出反应。关于种间信号（它会中断信息素吸引）的信息在特定的MGC - glomerulus中进行处理，并且在整个AL中在很大程度上与信息素信息分开。许多输出神经元能够准确地编码刺激时间特征的变化。
