Bedwell Stacey A, Billett E Ellen, Crofts Jonathan J, MacDonald Danielle M, Tinsley Chris J
Division of Biosciences, School of Science and Technology, Nottingham Trent University Nottingham, UK.
Front Syst Neurosci. 2015 May 20;9:80. doi: 10.3389/fnsys.2015.00080. eCollection 2015.
Understanding the structural organization of the prefrontal cortex (PFC) is an important step toward determining its functional organization. Here we investigated the organization of PFC using different neuronal tracers. We injected retrograde (Fluoro-Gold, 100 nl) and anterograde [Biotinylated dextran amine (BDA) or Fluoro-Ruby, 100 nl] tracers into sites within PFC subdivisions (prelimbic, ventral orbital, ventrolateral orbital, dorsolateral orbital) along a coronal axis within PFC. At each injection site one injection was made of the anterograde tracer and one injection was made of the retrograde tracer. The projection locations of retrogradely labeled neurons and anterogradely labeled axon terminals were then analyzed in the temporal cortex: area Te, entorhinal and perirhinal cortex. We found evidence for an ordering of both the anterograde (anterior-posterior, dorsal-ventral, and medial-lateral axes: p < 0.001) and retrograde (anterior-posterior, dorsal-ventral, and medial-lateral axes: p < 0.001) connections of PFC. We observed that anterograde and retrograde labeling in ipsilateral temporal cortex (i.e., PFC inputs and outputs) often occurred reciprocally (i.e., the same brain region, such as area 35d in perirhinal cortex, contained anterograde and retrograde labeling). However, often the same specific columnar temporal cortex regions contained only either labeling of retrograde or anterograde tracer, indicating that PFC inputs and outputs are frequently non-matched.
了解前额叶皮质（PFC）的结构组织是确定其功能组织的重要一步。在此，我们使用不同的神经元示踪剂研究了PFC的组织。我们将逆行示踪剂（荧光金，100 nl）和顺行示踪剂[生物素化葡聚糖胺（BDA）或荧光红宝石，100 nl]注入PFC各亚区（边缘前区、腹侧眶区、腹外侧眶区、背外侧眶区）沿PFC冠状轴的部位。在每个注射部位，分别进行一次顺行示踪剂注射和一次逆行示踪剂注射。然后在颞叶皮质分析逆行标记神经元和顺行标记轴突终末的投射位置：颞叶区Te、内嗅皮质和梨状周皮质。我们发现了PFC顺行连接（前后轴、背腹轴和内外侧轴：p < 0.001）和逆行连接（前后轴、背腹轴和内外侧轴：p < 0.001）均存在有序排列的证据。我们观察到，同侧颞叶皮质中的顺行和逆行标记（即PFC的输入和输出）常常相互对应（即同一脑区，如梨状周皮质的35d区，同时含有顺行和逆行标记）。然而，通常同一特定柱状颞叶皮质区域仅含有逆行或顺行示踪剂的标记，这表明PFC的输入和输出常常不匹配。
