2007年10月31日，北京生命科学研究所罗敏敏实验室在Journal of Neurophysiology杂志上发表了题为“Cortical-Like Functional Organization of the Pheromone-Processing Circuits in the Medial Amygdala”的文章。该文章揭示了内侧杏仁核处理信息素信息的基本神经环路。
信息素（pheromone）可以调节动物的社会行为和生殖行为，在处理信息素信号的神经通路中，内侧杏仁核处于核心位置。目前为止，内侧杏仁核处理信号的细胞机制尚未被阐明。曾经有学者提出内侧杏仁核采用类似纹状体的神经环路。纹状体向其目标区域提供抑制性投射，投射神经元呈星型，有延迟放电等独特的生理特性。在此一研究中，罗敏敏实验室的卞希玲运用多种手段检验内侧杏仁核的细胞是否具备纹状体细胞的特性。
罗敏敏实验室用神经示踪技术，遗传标记GABA能神经元的方法，以及对谷氨酸能的突触进行免疫组化的办法，证明内侧杏仁核对下丘脑腹内核主要提供兴奋性输出。全细胞膜片钳记录的结果显示：投射到腹内核的神经元在细胞形态和内在特性方面形成均一的群体。几乎所有的神经元都有H电流和T电流，这些神经元的树突会延伸至内侧杏仁核的外层来，以接受上一级感觉皮层的直接的兴奋性输入。它们还接受局部GABA能的神经元的抑制性输入。这些结果表明：内侧杏仁核通过独特的皮层环路，而不是采用纹状体环路来处理信息素信息。本工作对处理信息素的神经环路提供了重要数据。
博士生卞希玲为本文第一作者，论文的其他作者还有日本群马大学的Yuchio Yanagawa和耶鲁大学的陈伟博士，罗敏敏博士为本文通讯作者。此项研究由中国科技部, 北京市政府，中国自然科学基金, 人类前沿科学计划等资助，在北京生命科学研究所完成。（援引：北京生命科学研究所）
原始出处:
J Neurophysiol (October 31, 2007). doi:10.1152/jn.00902.2007
Submitted on August 13, 2007
Accepted on October 25, 2007
Cortical-like Functional Organization of the Pheromone-processing Circuits in the Medial Amygdala
Xiling Bian1, Yuchio Yanagawa2, Wei R Chen3, and Minmin Luo4*
1 Institute of Biophysics, Chinese Academy of Sciences, Beijing , Beijing, China; NIBS, Beijing , Beijing, China
2 Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine and SORST, Maebashi , Japan
3 Department of Neurobiology, Yale University, New Haven, Connecticut, United States
4 NIBS, Beijing , Beijing, China
* To whom correspondence should be addressed. E-mail: luominmin@nibs.ac.cn .
The medial amygdala (MeA) is a critical center for processing pheromonal signals that regulate social and reproductive behaviors, but the fundamental cellular mechanisms underlying signal processing in the MeA have remained largely unknown. Some studies suggest that the MeA belongs to the striatum and provides inhibitory output to hypothalamic areas including the ventromedial hypothalamus (VMH). By combining tract tracing, genetic labeling of GABAergic neurons, and immunostaining against markers for glutamatergic synapses, we found that a majority of MeA neurons projecting to the VMH are glutamatergic. Whole-cell patch clamp recordings revealed that VMH-projecting neurons form a homogeneous population in terms of morphological and intrinsic properties. Nearly all cells possess Ih and IT and in some cases they can give rise to post-inhibitory rebound spikes. Morphological analysis of neurobiotin filled cells revealed neurons with long dendritic arbors that extend to the MeA external layer and within the amygdala. Thus, the VMH-projecting neurons in the MeA differ from the medium spiny neurons, the principal neurons of striatum, in terms of intrinsic physiological properties and morphology. In contrast, they resemble a subset of pyramidal cells in deep piriform cortex. Similar to pyramidal cells in piriform cortex, the VMH-projecting neurons in the MeA received direct excitatory input from their upstream sensory areas and inhibitory input from local GABAergic neurons. We conclude that pheromonal signals relayed to the VMH are processed by unique cortical, but not striatal, circuitry in the MeA.
