Chemosensory Processing in Chemical Communication

描述（由申请人提供）：对大多数哺乳动物来说，化学通讯是同类信息的重要来源。即使在人类中，同居女性的月经同步也是基于气味线索进行潜意识交流的证据。许多证据不太充分的轶事表明，个体之间的化学通讯也可能携带其他信息。在许多哺乳动物中，主要的嗅觉系统和辅助系统，犁鼻器及其相关的中枢神经通路，共同作用，对行为有很大的影响。人类是否存在功能性的犁鼻器官尚不清楚，但大脑结构进化到处理犁鼻信息，内侧和皮质内侧杏仁核，在人类大脑中仍然突出，仍然接受化学感觉输入。本提案描述了研究这些大脑区域功能的实验。这些研究的模型系统是导致雄性仓鼠繁殖和领土行为的化学通讯。通过快速诱导的c-fos基因的表达来评估，在交配或雌性化学信号刺激时，前脑中最明显的事件是中央犁鼻神经通路及其连接区域的激活。来自雌性的化学感觉刺激和来自其他雄性的领土化学信号强烈地激活了雄性仓鼠的这条通路，包括杏仁核的前部和后部。初步数据表明，来自其他物种的化学感觉刺激，对仓鼠具有重要的生物学意义，但与“社会”无关，会强烈激活该通路的一个分支的第一阶段（前内侧杏仁核），但这种激活不会传递到下一个大脑区域（后内侧杏仁核）。通过电刺激或兴奋性药物对犁鼻通道的人工刺激也能激活杏仁核前部而不是后部内侧。我们将验证杏仁核中存在一个功能性过滤器的假设，该过滤器根据其社会相关性选择输入信息，并由后内侧杏仁核继续传递和处理。辅助嗅球，系统中的一个优先继电器，对相同的刺激表现出不同的选择性。我们将使用电生理学和c-los基因表达来证实这些反应的选择性，并研究激活的空间和时间模式，或某些类型细胞的激活，是否可能是机制。

DESCRIPTION (provided by applicant): For most mammals, chemical communication is an important source of information about others of the same species. Even in humans, the well-documented menstrual synchrony among women living together is evidence for subliminal communication based on odor cues. Numerous less well-documented anecdotes suggest that chemical communication may also carry other information between individuals. In many mammals, the main olfactory system and an accessory system, the vomeronasal organ and its associated central neural pathways, act together and have a large influence on behavior. The presence of functional vomeronasal organs in humans is questionable but the brain structures evolved to process vomeronasal information, the medial and cortico-medial amygdala, are still prominent in the human brain and still receive chemosensory input. This proposal describes experiments to investigate the function of these brain regions. The model system for these studies is the chemical communication that leads to male hamster reproductive and territorial behavior. Activation of the central vomeronasal neural pathway and the regions it connects to, are the most obvious events in the forebrain during mating or stimulation with female chemosignals - as assessed by the expression of the rapidly induced gene c-fos. Chemosensory stimuli from females and territorial chemical-signals from other males strongly activate this pathway in male hamsters, including both the anterior and posterior medial amygdala. Preliminary data suggest that chemosensory stimuli from other species, biologically important but with no "social" relevance for hamsters strongly activate the first stage of one branch of the pathway (anterior medial amygdala), but that activation is not passed on to the next brain region (posterior medial amygdala). Artificial stimulation of the vomeronasal pathway by electrical stimulation or an excitatory drug also activates anterior but not posterior medial amygdala. We will test the hypothesis that there is a functional filter in the amygdala that selects input information for onward transmission and processing by posterior medial amygdala on the basis of its social relevance. The accessory olfactory bulb, a prior relay in the system, appears differently selectivity for the same stimuli. We will use electrophysiology and c-los gene expression to confirm these selectivities of response and to investigate whether spatial and temporal patterns of activation, or the activation of certain classes of cells, could be the mechanism.