Cádiz-Moretti Bernardita, Abellán-Álvaro María, Pardo-Bellver Cecília, Martínez-García Fernando, Lanuza Enrique
Laboratori de Neuroanatomia Funcional Comparada, Departament de Biologia Cel⋅lular i Biologia Funcional, Facultat de Ciències Biològiques, Universitat de València València, Spain.
Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I Castelló de la Plana, Spain.
Front Neuroanat. 2016 Dec 23;10:125. doi: 10.3389/fnana.2016.00125. eCollection 2016.
The transitional zone between the ventral part of the piriform cortex and the anterior cortical nucleus of the amygdala, named the cortex-amygdala transition zone (CxA), shows two differential features that allow its identification as a particular structure. First, it receives dense cholinergic and dopaminergic innervations as compared to the adjacent piriform cortex and amygdala, and second, it receives projections from the main and accessory olfactory bulbs. In this work we have studied the pattern of afferent and efferent projections of the CxA, which are mainly unknown, by using the retrograde tracer Fluorogold and the anterograde tracer biotinylated dextranamine. The results show that the CxA receives a relatively restricted set of intratelencephalic connections, originated mainly by the olfactory system and basal forebrain, with minor afferents from the amygdala. The only relevant extratelencephalic afference originates in the ventral tegmental area (VTA). The efferent projections of the CxA reciprocate the inputs from the piriform cortex and olfactory amygdala. In addition, the CxA projects densely to the basolateral amygdaloid nucleus and the olfactory tubercle. The extratelencephalic projections of the CxA are very scarce, and target mainly hypothalamic structures. The pattern of connections of the CxA suggests that it is indeed a transitional area between the piriform cortex and the cortical amygdala. Double labeling with choline acetyltransferase indicates that the afferent projection from the basal forebrain is the origin of its distinctive cholinergic innervation, and double labeling with dopamine transporter shows that the projection from the VTA is the source of dopaminergic innervation. These connectivity and neurochemical features, together with the fact that it receives vomeronasal in addition to olfactory information, suggest that the CxA may be involved in processing olfactory information endowed with relevant biological meaning, such as odors related to reproductive or defensive behaviors.
梨状皮质腹侧部分与杏仁核前皮质核之间的过渡区，称为皮质 - 杏仁核过渡区（CxA），具有两个不同特征，使其可被识别为一个特殊结构。首先，与相邻的梨状皮质和杏仁核相比，它接受密集的胆碱能和多巴胺能神经支配；其次，它接受来自主嗅球和副嗅球的投射。在本研究中，我们使用逆行示踪剂荧光金和顺行示踪剂生物素化葡聚糖胺，研究了CxA主要未知的传入和传出投射模式。结果表明，CxA接受一组相对受限的脑内连接，主要起源于嗅觉系统和基底前脑，杏仁核的传入较少。唯一相关的脑外传入来自腹侧被盖区（VTA）。CxA的传出投射与来自梨状皮质和嗅觉杏仁核的输入相互对应。此外，CxA密集投射到基底外侧杏仁核和嗅结节。CxA的脑外投射非常稀少，主要靶向下丘脑结构。CxA的连接模式表明它确实是梨状皮质和皮质杏仁核之间的过渡区域。用胆碱乙酰转移酶进行双重标记表明，来自基底前脑的传入投射是其独特胆碱能神经支配的起源，用多巴胺转运体进行双重标记表明，来自VTA的投射是多巴胺能神经支配的来源。这些连接性和神经化学特征，以及它除了嗅觉信息外还接受犁鼻器信息这一事实，表明CxA可能参与处理具有相关生物学意义的嗅觉信息，例如与生殖或防御行为相关的气味。
